Great Marsh Boardwalk

Leopold Memorial Reserve

Great Marsh Boardwalk Site & Budget Analyses

Gregory A. Tenn

Leopold Memorial Reserve

Great Marsh Boardwalk Site & Budget Analyses

Gregory A. Tenn, ASLA

Design and Planning Associate Aldo Leopold Foundation

2015

Special thanks to Susan Flader for providing the initiative and support that has brought the Great Marsh Boardwalk project so many steps closer to reaching the Leopold Shack.

Disclaimer: This document is intended to provide generalized information pertaining only to the Great Marsh Boardwalk project. It should not be utilized for construction purposes or be considered in lieu of professional consultation regarding project planning, design, engineering, and/or construction.

Cover Image: Great Marsh in Early Autumn (Tenn, G., 2014)

Contents

02 09 10

Curbs & Guardrails............... 40 Floodplain Considerations ... 46 Additional Features .............. 50

Executive Summary Introduction Site Analysis Aldo Leopold in Wisconsin ... 10 Leopold Memorial Reserve .. 14 Glacial Topography .............. 16 Wisconsin River Floodplain.. 17 Soil Classification ................ 18 Wetland Classification & Permitting ............................. 22 Boardwalk Route & Trails .... 24

26 27 28

Summer wildflowers at the Leopold Center (Tenn, G., 2014)

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(A1) Shallow Foundations: Volunteer-Led Installation .. 52 (A2) Shallow Foundations: Contractor Installed ............ 53 (B1) Helical Pile Foundation: Standard PT Boardwalk ....... 54 (B2) Standard PT w/ Vertical Guardrails ............................. 56 (B2a) Phased Approach: 500ft Segment to 1st Pond .. 58 (B3) Standard PT w/ Welded Wire Mesh Guardrails........... 60 (C1) Helical Pile Foundation: White Oak & Tension Cable . 62 (C2) Helical Pile Foundation: Ipe & Tension Cable ............. 64

Budget Scope and Overview Components of Estimates Estimates Custom Manufacturing速 ... 28 Foundations: Helical Piles ... 30 Decking Materials ................ 32 Substructure/Framing .......... 36

Budget Scenarios

66 72

Photo & Image Credits Selected Resources

Executive Summary Each year, the Aldo Leopold Foundation welcomes thousands of visitors to learn about the life and work of Aldo Leopold and to explore the land which helped influence his concept of a “Land Ethic.” Many come to see the historic Leopold Shack from which Leopold and his family began their famous experiment in land restoration and which was featured in his best known work, A Sand County Almanac.

In 2012, the foundation began envisioning a means of creating a pedestrian corridor between the Leopold Center and the historic Shack and Farm.

The visioning process included the enhancement of an existing system of recreational trails, as well as the development of a boardwalk spanning the largest impediment to this goal—an undeveloped floodplain wetland known as the Great Marsh.

Historic Context: Aldo Leopold grew up at the turn of the 20th century during the reform-minded Progressive Era of the United States. Trained as part of the country’s first generation of foresters, his early career took him to the expansive forests of the American Southwest. There his experiences helped to fundamentally shape his attitudes toward natural resource management and the environment.

He eventually moved to Madison, Wisconsin and in 1935 acquired a farmstead along the Wisconsin River. There he, his wife Estella, and their five children worked to restore health to the land, and renovated an old chicken coop that would serve as their home away from home. They lovingly called it the “Shack.”

The following years proved arduous but fruitful, and their experiences influenced what is widely regarded as Leopold’s most influential work, A Sand County Almanac. In it, he coined the term Land Ethic to provide context to the complex relationship between people and the environment. Unfortunately, Leopold died in 1948, only one year before its publication.

Approximately two decades after Aldo Leopold’s death, pressure to develop the land surrounding the Leopold Shack led to the establishment of the Leopold Memorial Reserve (LMR). A land management plan was developed, a full-time manager was appointed, and a tradition of creating and sharing knowledge about working on the land began.

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In 1982, the Aldo Leopold Foundation (ALF) was established by the Leopold children and grandchildren. Its mission emphasizes the continued study of science and philosophy on the land, the legacy of Aldo Leopold, and the Land Ethic. Today, the foundation’s lands have grown to over 600 acres, and it helps influence and inspire individuals, as well as private and public entities, on a national level. From the recently built Leopold Center, the foundation invites visitors to explore the LMR while continuing to promote mindful land stewardship and share knowledge that is acquired from their ongoing and evolving management practices.

Project Rationale: The Leopold Shack and Leopold Center can be accessed via Levee Road and are separated by approximately one mile. Unfortunately, little infrastructure exists to accommodate pedestrians. Additionally, a floodplain wetland known as the Great Marsh limits the potential for the development of trails between the sites. A boardwalk through the marsh would create a safe pedestrian corridor while also allowing users to explore some of the rich and unique cultural, historical, and ecological landscapes that influenced Aldo Leopold’s work and writings.

Site Analysis: The LMR is located in a diverse ecological region surrounded by well-known environmental attractions such as the Dells of the Wisconsin River and Devil’s Lake State Park. However, some of the same factors making this area attractive to visitors also pose challenges to development.

In planning for the development of a boardwalk in the Great Marsh, this document considers local geology and soil characteristics, topography, floral and faunal communities, site history, and visitor experience. Of primary concern to development are the influence of the site’s organic surface soils, its location within a floodplain wetland of the Wisconsin River, and efficient utilization of topographic variation within the relatively flat marsh.

Rich in organic content, the marsh’s surface soils can be unstable and provide little structural support.

A geotechnical analysis conducted in September of 2014 set out to analyze the suitability of subsurface soils for structural development. Results helped to

corroborate available site information and found conditions suitable for the implementation of a number of deep foundation systems.

While the marsh is essentially a flat basin, subtle variations in elevation can be utilized to positively influence user experience and reduce costs. Berms surrounding man-made ponds in the marsh provide vantage points and can be used to elevate the boardwalk above water levels. These previously disturbed areas are also more suitable for development than their relatively undisturbed surroundings.

The marsh is an active part of the Wisconsin River floodplain. Thus, potential flooding and its associated forces, as well as normally fluctuating water levels, must be considered in foundation design and placement of framing, decking, and guardrails.

Active use of both floodplain and wetland environments will also require appropriate permitting at local, state, and federal levels. However, structural design can reduce permitting requirements by limiting the introduction of “fill� materials into the environment. Associated lead-time, permitting costs, and compensatory mitigation activities would also be reduced. Working closely with regulatory agencies will help ensure a smooth process, and a preliminary permitting meeting with representatives from the United State Army Corps of Engineers (USACE), Wisconsin Department of Natural Resources (WI DNR), and Sauk County was held in May of 2014.

Budget Analysis Overview: At this preliminary stage, the budget analyses rely on professional consultation, assessment of other completed projects, general engineering principles, and best practices to develop estimates for boardwalk components.

Costs are divided amongst four component categories: foundations; decking; substructure/framing; and guardrails. Additional elements not critical to the structure of the boardwalk (e.g. multipurpose platforms, interpretive signage) are considered separately. All estimates include information pertaining to materials, design, installation best practices, code compliance, permitting, aesthetics, and functionality. Additionally, a single prefabricated shallow

foundation boardwalk system intended for use in similar environments was examined.

To allow for extrapolation to various boardwalk lengths, costs are described on a per linear deck-foot basis. With few noted exceptions, they include materials and necessary hardware. Labor costs are represented in budget summaries that provide overall costs for a few development scenarios.

Custom Manufacturing produces a shallow foundation system which rests directly upon the surface soils. The system is comprised of beveled square metal pans to which wooden posts are attached.

The company prefabricates all modular components of pressure treated lumber and delivers them to the installation site. Boardwalks of four, five, six, or eight feet in width can be installed by the manufacturer, a separate contractor, or volunteers.

The primary benefit of the system is its low cost.

However, the vast majority of savings are derived from the utilization of a shallow foundation system.

While inexpensive relative to deep foundation systems, they are limited with regard to stability and durability given the soil and hydrologic conditions in the marsh. (According to Custom Manufacturing, their foundation design assumes a soil bearing capacity of 1500psf. The geotechnical analysis revealed a compressive strength of surface soils to be 200psf.)

Given the relative simplicity of the system, a volunteer-led installation could also be implemented to achieve further savings. However, this scenario fails to recognize the associated costs of project management, coordination, and oversight/quality control.

Deep foundations bearing on subsurface soils can provide added stability and durability relative to shallow foundations but also represent a greater immediate expense. Helical piles (also screw piles or helical piers) are primarily considered for this project over other systems (e.g. friction piles), because they are relatively cost effective and will likely prove effective in the deep sandy soils found within the Great Marsh. They are also flexible with regard to design and application, can be installed with small equipment that limits physical site impacts, and can provide

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immediate feedback during installation. It is also important to note that unlike shallow foundations, the use of helical piles may result in less stringent regulatory requirements at state and federal levels.

Price varies based on local site conditions that determine final installed depth and can reach over $1000 per pile. However, a project of this size should provide an economy of scale, and maximizing intervals between foundations will also reduce costs.

Budget scenarios utilized a price point of $900 per piling with an average interval of 12 feet.

Decking materials offer great opportunity for customizing and may vary considerably in terms of strength, durability, availability, environmental impacts, installation, aesthetics, and cost. Thus, materials are first categorized by type: domestic pressure treated lumber; domestic decay resistant lumber; exotic and domestic hardwoods; natural fiber-plastic composites and recycled plastics; or steel, aluminum, and fiberglass panels.

Even within categories, significant price variation depending on material qualities and availability is not uncommon. A large selection falls beneath $70 per linear-deck-foot, but prices over $200 are also possible. Most material and hardware costs fall within a range of $10 to $100 per linear-deck-foot.

At the low end, pressure treated southern yellow pine lumber represents the most economical choice and will be a durable choice if care is taken to specify the appropriate grade and finish.

Decay resistant lumber (e.g. redwood, eastern cedar) can provide desirable aesthetic qualities with good durability in exterior applications. Once again, quality varies, and higher grades can be expensive. As they rely on older growth stands, it is important to consider the environmental implications of specifying such quality grades.

With natural fiber composites or recycled plastic materials, care should be taken when selecting both manufacturer and grade. High quality materials are available, but “maintenance free� claims are generally misleading. Decay from insects, moisture, and

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ultraviolet light are possible, and compared to lumber, material strength is generally also reduced.

Hardwood lumber is an ideal choice from the standpoint of both durability and aesthetics.

However, expense can be higher than many materials, and installation may require more preparation (e.g. pre-drilling). Tropical hardwoods such as Ipe have become more common, but care should be taken to utilize sustainable sources. On the other hand, domestic hardwoods may be difficult to source in the quantities necessary for a project of this size.

Metal or fiberglass grating offers a unique and durable choice and is relatively competitive with composites and hardwoods in terms of cost. Deck framing design may need adjustment to accommodate this type of decking. Additionally, the appropriate spacing and pattern of grating should be chosen to enable comfortable pedestrian and wheeled traffic.

Framing is comprised of structural beams and joists that transfer loads to the foundation and support mounted objects such as guardrails. While variation in deck layout, load specifications, materials, size and configuration of components, and hardware will create price variation, specifications for beams and joists is relatively straightforward given the need to follow prescriptive structural design guidelines.

As a standard and economical material, pressure treated southern yellow pine is the only material included in final budget scenarios. Taken together, beams and joists account for approximately $10-$30 per linear-deck-foot of the total cost. A large portion of this cost is associated with joist mounting hardware. To avoid underestimating costs, beam-to-post attachments are also included in estimates. However, they will be unnecessary if they are provided with helical pile foundations. (Costs for untreated Douglas fir lumber are approximately 15–25% lower, but untreated lumber is not recommended for structural purposes in exposed conditions.)

Placement should consider regular high water levels within the marsh (approximately 806 feet) to avoid exposure to alternate wet and dry periods that can lead to decay. Additionally, cantilever of beams

and joists should be considered as a means of providing additional deck space for signage or seating.

While the size of support members and, thus, cost of framing may increase in a given area, gains in functional deck space may limit the need for additional (and costly) foundations.

Guardrails and curbs are necessary for safety but can also serve as visual cues, provide areas for rest, offer a sense of security, be aesthetically appealing, and deter access to sensitive environmental areas.

Great aesthetic variety can be achieved in their implementation, but aspects such as height, load bearing capacity, permeability/porosity (e.g. intermediate rail spacing), and application/location is governed by regulatory standards.

With regard to recreational trails, the applicability of regulatory standards such as those established by the International Building Council (IBC) is not always straightforward. For components of recreational trails (including bridges and boardwalks), the United States Forest Service (USFS) adopts standards established by the American Association of State Highway and Transportation Officials (AASHTO) and the International Code Council’s International Building Code (IBC). Their application is based on anticipated use and risk. Here, direction for standards is taken from both the USFS guidelines for moderate risk recreational trails and the IBC. Ultimately, local authorities will have jurisdiction over plan approval.

Guardrails are located where the finished deck height is greater than 30 inches above grade, with curbs along the remaining length of the boardwalk.

This amounts to guardrail coverage for approximately 45% of the boardwalk (see below). Curb costs were generally under $10 per linear-deck-foot and basic horizontal railings were under $20 per linear-deckfoot. However, baluster or welded wire mesh installations can create a more elegant look for between $20 and $30 per linear-deck-foot.

Deck height influences railing placement and is influenced by flood risk. Ultimately, avoiding flood damage by increasing height must be weighed against the increasing costs of guardrails, additional

lateral support for foundations, and potential loss to aesthetic or experiential functions. At a deck height of 808 feet above sea level (corresponding to the lowest 100-year flood elevation in the marsh), guardrails would be required along 70% of the boardwalk route.

Based on a topographic analysis, a deck height of 807.5 feet is recommended and reduces the guardrail requirements to 45%. Conveniently, this elevation also coincides with the elevation of Levee Road where it is crossed by the boardwalk route.

Additional Features: While not structurally necessary, elements such as seating, signage and multipurpose decks add programmatic and functional values to the boardwalk. They can reduce traffic congestion, offer a place for rest, and enhance interaction with environmental or historic elements.

Cost for some of these elements is provided in final budget scenarios. While unit costs are provided for bench-style seating ($50/unit) and interpretive signage ($1000/unit), deck estimates are derived directly from per linear-deck-foot costs associated with the appropriate budget scenario. For instance, a 96 square foot deck in Scenario B1 (see next page) costs approximately $3,884, whereas it is approximately $3,986 in Scenario B3 due to upgraded railings.

Additionally, a large pond berm along the boardwalk route offers a suitable location for a large multipurpose deck (approximately 500 square feet) that could accommodate formal groups or functions and would be a focal element of the boardwalk. This elevated location offers expansive views, a large open area with previously disturbed soils, and also represents the approximate midpoint along the route. Costs of such a feature were not specifically determined.

However, given the need for additional foundations, a conservative estimate based on smaller deck spaces totals approximately $50,000.

Key Takeaways: 1. The implementation of a shallow foundation system is attractive from an economic standpoint, but surface soil instability, site hydrology, and regulations regarding fill material must also be considered.

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2. A site geotechnical analysis supports the use of a deep foundation system bearing on subsurface soils.

Helical pile foundations can be designed to accommodate various site conditions and are a durable option. They can also be installed with relatively small equipment and with relatively little disturbance to surroundings. Designed properly, such a system may be subject to fewer permitting requirements.

3. Decking costs vary greatly depending on type of material and quality or grade. Care should be taken to select a material that is aesthetically pleasing, functionally appropriate, cost efficient, and easily sourced. For instance, some metal grating may not allow wheeled traffic; hardwood boards will require added attention during installation (e.g. pre-drilling); and composite materials may be prone to rot or UV damage and often make use of specialized hardware for installation. Pressure treated southern yellow pine lumber provides an economical and durable solution that is also widely available in this region.

4. Deck framing should utilize pressure treated lumber and be set above the regular water level within the marsh, in order to reduce chances of decay from alternating wet and dry periods. For relatively little additional cost, design loads can be increased to account for potential future uses (e.g. gatherings, vehicular use). Cantilevers can also be incorporated into the design to extend decking to accommodate signage or seating.

5. Guardrails can provide additional benefits beyond physical safety, but reducing the need for guardrails can also provide substantial savings. A finished deck elevation of 807.5 feet requires that about 45% of the boardwalk route maintain a guardrail.

Most spaces intended specifically for groups or gatherings will likely require a guardrail, and a curb should be installed in all areas where guardrails are excluded.

6. Multipurpose decks/gathering areas, interpretive signage, seating, and shelter should be offered intermittently along the boardwalk route to enhance overall experience. The pond berms along the route offer advantages for the incorporation of decks spaces by providing good vantage points, larger open areas, and previously disturbed soils.

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Budget scenarios were created to present a summary of material pricing data. Options for each scenario draw from the information provided in the booklet and balance cost with accessibility, user experience, safety, and general functionality.

Scenario Notes:

• Shallow pan foundations and helical piles are spaced at 8 and 12 foot intervals, respectively.

• A minimum six foot deck width is recommended and, with one exception (scenario A1), is applied to all scenarios.

• A deck elevation of 807.5ft. above sea level is utilized, and guardrails are applied where the walking surface is 30in. or more above grade (45% of the length of the boardwalk).

Curbing is applied along the remainder.

• For all scenarios, framing is comprised of pressure treated southern yellow pine. Sizing was based on minimum code requirements for the indicated deck width, spans, and 40psf live loads and 10psf dead loads.

• With the exception of scenario A1, an installation cost estimate of $60 per linear-deck-foot was applied. Installation of helical piles is included in foundation estimates.

• Except for the phased approach (scenario C2a), the signage and deck allowance includes six 96sqft decks with a pair of bench seats and an interpretive sign for each.

• Consulting/design, permitting, and cost contingency estimates are not included in these summaries (except in the phased approach, scenario C2a).

(A1) Shallow Foundations: Volunteer-led Installation

• • • • • •

4 foot deck width horizontal railing (AASHTO compliant), 2x4 curbs costs do not include volunteer coordination or management price per linear foot: $58 price per 3000 feet: $172,784 price w/ signage and deck allowance: $187,678

(A2) Shallow Foundations: Contractor Installed

• • • • •

horizontal railing (USFS low-risk, OSHA compliant), 2x6 PT SYP deck boards price per linear foot: $124 price per 3000 feet: $370,901 price w/ signage and deck allowance: $389,369

(B1) Helical Pile Foundation: Standard PT Boardwalk

• • • • •

horizontal railing (USFS low-risk, OSHA compliant) 2x8 PT SYP deck boards price per linear foot: $243 price per 3000 feet: $728,305 price w/ signage and deck allowance: $758,210

(B2) Standard PT w/ Vertical Guardrails

• PT horizontal top and bottom rail with intermediate vertical balusters (IBC compliant) • 2x8 PT SYP deck boards • price per linear foot: $244/ft • price per 3000 feet: $733,315 • price w/ signage and deck allowance: $763,381 (B3) Standard PT w/ Welded Wire Mesh Guardrails

• galvanized welded wire mesh with PT SYP facing, rails, and caps (IBC compliant) • 2x8 PT SYP deck boards • price per linear foot: $249/ft • price per 3000 feet: $747,371 • price w/ signage and deck allowance: $777,887 (C1) Helical Pile Foundation: White Oak & Tension Cable

• 5/4x6 quarter-sawn white oak decking • stainless steel tension cable guardrails w/ PT SYP posts and caps (IBC compliant) • price per linear foot: $299/ft • price per 3000 feet: $898,464 • price w/ signage and deck allowance: $933,815 (C2) Helical Pile Foundation: Ipe & Tension Cable

• 5/4x6 ungrooved Ipe decking • stainless steel tension cable guardrails with Ipe lumber posts and caps (IBC compliant) • price per linear foot: $376/ft • price per 3000 feet: $1,126,713 • price w/ signage and deck allowance: $1,169,367

Phased Approach: In general, scenarios utiliz-

ing pressure treated lumber should offer the desired level of functionality and durability at a reasonable price point. Modest upgrades such as the use of larger deck boards (e.g. 2x8 vs 2x6) and upgraded railings will provide desirable aesthetic enhancement. Even so, higher than expected project cost estimates may make a phased approach to project implementation desirable.

While it may increase overall costs by limiting economies of scale, increasing mobilization costs, and carrying the risk of potential price increases with time, such an approach would significantly reduce immediate financial exposure. Planned correctly, building an initial project phase could also accomplish many of the desired programmatic and functional goals while eliciting excitement about further project development.

A suggested terminus for this initial phase is found along the north berm of the east-most pond. Using scenario B2 as a template over the proposed distance of approximately 500 feet, the project budget falls significantly. The estimate below accounts for increased railing requirements over this short route segment, as well as an origin and termination deck, seating, and interpretive signage.

(B2a) Phased Approach Recommendation: 500ft segment

• • • • • • •

500ft segment leads to first pond west of marsh entrance baluster guardrails (IBC compliant) 2x8 PT SYP deck boards price per linear foot: $253/ft price per 500 feet: $126,569 price w/ signage and deck allowance: $138,869 price w/ consultation & contingency (15%): $157,399

Moving Forward: By examining site conditions, design principles, best practices, regulatory requirements, and costs, it is hoped that this document will further facilitate the identification of opportunities and constraints related to programmatic and functional elements of the Great Marsh Boardwalk project. Once clear project goals are established by the Aldo Leopold Foundation and its stakeholders, a formal design that balances quality, budget, and time frame can be developed. Already, the past year has seen progress made in a number of key areas: • Through coordination with the ALF stewardship crew, outside volunteer organizations, and individual volunteers, approximately 700 feet of pedestrian trails near the Leopold Center have been either created or enhanced.

• A geotechnical analysis of marsh subsurface soils has been completed and will inform the design of a safe and structurally sound foundation system.

• Contact has been made with a number of potential project consultants, contractors, and outside organizations. Many have shown an interest in the project, and a number of their shared experiences and knowledge have assisted in completion of this booklet.

• Representatives from the Army Corps of Engineers, Wisconsin Department of Natural Resources, and Sauk County have visited the site and taken part in an pre-application permit meeting to discuss project goals and the regulatory process. Establishing these relationships will help to ensure smooth forward progress as the project approaches permitting stages.

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Introduction “We can be ethical only in relation to something we can see, feel, understand, love, or otherwise have faith in.”

-- Aldo Leopold, A Sand County Almanac

The Leopold Shack (courtesy Aldo Leopold Foundation Archives, ca 1936)

Aldo Leopold with binoculars (courtesy Aldo Leopold Foundation Archives, 1947)

Situated prominently between the Aldo Leopold Shack and Farm and the Aldo Leopold Foundation’s Leopold Center, the “Great Marsh” was an inspiration for one of Aldo Leopold’s most influential works, A Sand County Almanac. Each year, the Aldo Leopold Foundation (ALF) welcomes thousands of visitors to these landmarks and the other ecologically, culturally, and historically significant places that surround them within the Leopold Memorial Reserve (LMR).

Wisconsin River and the presence of an environmentally sensitive and significant wetland along its length, the magnitude of the project can appear daunting.

However, when broken down into individual, constituent components, such constraints become manageable and can lend themselves to great design and experiential opportunities.

In 2012, the Aldo Leopold Foundation began envisioning a means to provide visitors with access to the landscape of the Great Marsh. Planning for a boardwalk that would connect trails on either side of the marsh began thanks to the Ice Age Trail Alliance and enthusiastic support from a long-time ALF board member, Susan Flader.

Implementation of an approximately 3000 foot long boardwalk is no small feat, and the unique environment of the marsh offers additional challenges. Given its position within the floodplain of the

When completed, the Great Marsh Boardwalk will provide a cohesive link between the Leopold Shack and Leopold Center, as well a number of other significant landscapes found within the LMR. By creating further opportunities for immersion and enrichment within these landscapes, it is hoped that visitors will better understand the places and events that helped shape Aldo Leopold’s writing and philosophy and that they will leave with a greater sense of connection to the land than when they arrived. Additionally, it is hoped that their experiences will elicit individual insight into a concept which remains at the core of the Aldo Leopold Foundation’s mission—Leopold’s “Land Ethic.”

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Site Analysis Since being granted statehood in 1848, Wisconsin has produced many conservation-oriented thinkers. Though many of its contemporaries had contrasting views on important issues, the late 19th century Progressive Era in the United States fostered scientific reasoning and became a time of major political, economic, and cultural shifts. From Wisconsin, individuals such as Increase Allen Lapham, John Muir, Robert La Follette, and Charles Van Hise joined figures such as Susan B. Anthony, W. E. B. Du Bois, and Andrew Carnegie in shaping national dialogues. The era was also critical for natural resource management and saw important figures such as President Theodore Roosevelt and Gifford Pinchot offering new ideas and leadership in the field. In one form or another, their contributions must certainly have influenced the thinking of another influential Wisconsinite, Aldo Leopold.

Aldo Leopold in Wisconsin

Born in 1887 in Burlington, Iowa, Leopold was still young when Gifford Pinchot and Henry S. Graves established the Yale Forestry School in 1900. As a graduate of the school in 1909, Leopold became a member of the earliest generation of American foresters. Stationed in America’s Southwest, his experiences there were instrumental in shaping his views on natural resource management and conservation.

Returning to the Midwest in 1924, he eventually became a professor at the University of Wisconsin, Madison. There, research was beginning on the topic of ecological restoration at the university’s new arboretum, and in 1935 Leopold set out to experiment on his own.

Purchasing a depleted farmstead along the Wisconsin River, he and his family began working to restore health to the land.

Until his death in 1948, Leopold meticulously tracked the influence of these activities on his surroundings and elegantly shared his ideas regarding ecology and conservation ethics in A Sand County Almanac. The Aldo Leopold Foundation was founded to continue learning from direct work on the land and to share their knowledge while promoting a pragmatic approach to conservation and resource management.

The LMR is located along a stretch of the southern bank of the Wisconsin River in Sauk County, WI.

Sauk and Columbia Counties, WI (Tenn, 2014) 43°22’38,25”N and 89°40’10.37”W (Google Earth, 2013)

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Located in northern Sauk County, the Leopold Shack and Farm is approximately an hour’s drive north of Madison and a short distance from the cities of Baraboo (12 miles), Portage (10 miles), and Wisconsin Dells (11 miles). Today, much of the stretch of river between the cities of Portage and Wisconsin Dells, benefits from the knowledge of land management practices that have been shared by the Aldo Leopold Foundation. Approximately 16,000 acres were recently designated as an Important Bird Area (IBA). The location also places it near two of Wisconsin’s most prominent natural areas, Devil’s Lake State Park and the Dells of the Wisconsin River. Both were included in John Nolen’s report to the Wisconsin State Park Board in 1909, “State Parks for Wisconsin,” and both have become important attractions for locals and visitors alike. Other significant, nearby cultural areas include Natural Bridge State Park, the Man Mound Native American effigy mound, the Ice Age National Scenic Trail, and Fountain Lake Farm— John Muir’s boyhood home.

s i n

R i v e r

nearby natural and cultural areas

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W i s c

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Wisconsin Counties and Waterways (Tenn, 2014)

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Leopold Shack

Shack Prairie

Site Aerial The Wisconsin River flows approx-

imately 430 miles from its headwaters in Lac Vieux Desert in northern Wisconsin to its confluence with the Mississippi River at Wyalusing State Park in the southwestern part of the state. The point where the river turns suddenly eastward as it navigates around the Baraboo Hills and past Aldo Leopold’s Shack and Farm was formed near the end of the Wisconsin Glaciation some 11,000 years ago. Retreating ice allowed Glacial Lake Wisconsin to drain, and the torrential flood waters carved the cliffs that comprise the Dells of the Wisconsin River, located just a few miles upstream of the shack.

Great Marsh

Today, both the Shack and Leopold Center are accessible via a stretch of Wisconsin’s Rustic Road 49 (Levee Road). They are separated by less than one mile and are surrounded by a unique mixture of ecosystems that includes barrens, floodplain and hardwood forests, sedge meadow and emergent wetlands, as well as prairies and oak savanna.

The Great Marsh is a relatively undisturbed floodplain wetland situated between the Shack and Leopold Center. A prairie restoration to the southeast of the Shack provided Leopold with a direct view of wildlife in the marsh.

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“Great Marsh” Aerial (Tenn, 2014) DIGITAL ORTHOPHOTO (DOP) COVERAGE FOR SAUK COUNTY (US Department of Agriculture, 2008)

Aldo Leopold Foundation: Leopold Center

Sand Hill

Leopold Shack

Levee

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rmerl

y, Riv e

r Rd.)

Great Marsh

Columbia9211937_14-1164_7x9 historic aerial photograph (USDA, 1937)

The aerial photograph above was taken in 1937, only two years after Aldo Leopold purchased his farm in 1935. Though stressed from overuse and visibly denuded in some areas, many landmarks such as the Great Marsh, the driveway leading to the shack, and the Sand Hill are easily recognizable.

site history

Leopold Memorial Reserve When Aldo Leopold purchased his 35 acre farmstead in 1935, the land was worn, and the only standing structure was a small, dilapidated chicken coop.

However, this structure, the Shack, was refurbished and became the home from which the Leopolds undertook their famous experiment in environmental restoration. Published in 1949, A Sand County Almanac tells the story of this enduring landscape, how it was revitalized, and how Leopold’s efforts on the land shaped a concept he called the Land Ethic.

While going on to become his seminal work, Aldo Leopold would never see its success. He succumbed to a heart attack while fighting a neighboring grass fire near the present location of the Leopold Center.

After his death, Leopold’s wife Estella and their five children continued the work on the farmstead that the family began so many years earlier. However,

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the future integrity of this landscape was not always certain. A series of subdivided properties to the east of the Shack are a reminder of the development pressure facing the area after the completion of Interstate 90/94 to the south in the 1960s.

In order to protect the land surrounding the Leopold property, a cooperative management agreement was made amongst five landholding families (including the Leopolds) in 1967–68. Overseen by the L.R. Head Foundation and totalling 900 acres at that time, the land-trust was known as the Leopold Memorial Reserve and would become a proving ground for private cooperative land management over the decades to follow. A management plan was developed by Bob Ellarson, and Frank Terbilcox, one of the landowners, became the reserve’s full-time manager. Until his retirement in 1993, Frank acted as the

Great Marsh

Partial ALF Property Boundaries (Tenn, 2014)

The holdings of the Leopold family and, subsequently, the Aldo Leopold Foundation have increased from 35 acres to over 600. With the purchase of 305 acres from the Terbilcox family in 2011, a contiguous tract that includes the Great Marsh was established between the Leopold Center and Shack.

property boundaries

public face of the reserve, giving tours, disseminating information, and speaking to other land owners, companies, and educators.

In 1976, Aldo Leopold’s daughter Nina and her husband Charles (Charlie) Bradley returned to the area to start an active retirement. They built the Bradley Study Center near the west end of Levee Road and began the tradition of inviting fellows and students to live and learn on the reserve. Land management practices on the reserve continue to be informed by these and similar ongoing research efforts, as well as from field work conducted by Mr. Terbilcox and the stewardship crews that followed.

The Leopold children and grandchildren established the Aldo Leopold Foundation (ALF), in 1982.

On their 200 acres of the LMR, the ALF hoped to

continue the Bradley’s efforts by emphasizing science, philosophy, and the legacy of Aldo Leopold. As the organization has grown, so have the lands in its care. Purchased from the Terbilcox family in 2011, an additional 305 acres doubled the ALF’s holdings to over 600 acres. Activities are managed from the LEED Platinum certified Leopold Center which was built in 2007.

Presently, the LMR consists of over 1700 acres. The L.R. Head Foundation became the Sand County Foundation (SCF) in 1982 and continues to support private land owners in conservation. Though the SCF and the ALF have grown into separate entities with unique missions, their existence has made possible the preservation and improvement of the LMR while providing invaluable insights into the science and process of cooperative land management.

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Sand Hill

ponds and berms

Frank’s Hill Great Marsh Topography (Tenn, 2014)

Topographic models reveal glacial features such as moraines, as well as subtle elevation changes within the Great Marsh. A number of ponds were created as part of the LMR’s management plan. Their berms offer opportunities for development on previously disturbed ground and can provide critical vantage points in the flat marsh.

elevation model

Glacial Topography While the gentle marsh topography appears to have little variation, even subtle changes can speak to differences in hydrology, microclimate, vegetation, and soils that can influence the course of development.

Much of the topographic variation within the Great Marsh can be traced back to glacial activity, and reminders of Wisconsin’s glaciated past both within and around the LMR abound. The ancient quartzite of the Baraboo Hills marks the edge of glacial advance in this part of Wisconsin. Deep, sandy marsh soils were deposited by outflow from Glacial Lake Wisconsin and are surrounded by glacial moraines.

Near the Leopold Center, Frank’s Hill offers visitors panoramic views of the marsh and surroundings, and the Sand Hill provides high ground and more stable soils for development that were used to the advantage of both the Shack and an original farmhouse.

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High resolution elevation models assist in the delineation of such landscape features and can provide other insights. For instance, the marsh contains elevated berms surrounding man-made ponds. Due to their altered hydrological regimes and soils, they support a plant community reminiscent of disturbed upland sites. Development in these areas would help protect more sensitive plant communities, provide vantage points over the flat landscape, and offer some respite over high water. dells/dalles

• a gorge or area of exposed bedrock extinct glacial lake

• a lake that drained after a glacier or glacial lobe retreated glacial moraine

• a ridge of unconsolidated materials (e.g. gravel, sand, and boulders) that was deposited by glacial activity • terminal/end moraines form where glacial advance ceases

Sand Hill

Frank’s Hill Great Marsh Floodplain (Tenn, 2014)

While flood risk is partially mitigated by structures such as the Kilbourn Dam, the potential for annual flooding within the Great Marsh is real. Any development therein must acknowledge the design and regulatory implications of its position within the 100-year floodplain of the Wisconsin River.

Wisconsin River floodplain

Wisconsin River Floodplain The Wisconsin River has long played a major role in development, and today a series of 26 hydroelectric dams along the river have earned it the nickname of “The Nation’s Hardest Working River.” These dams also serve another function: to mitigate the risk of flood damage along its banks.

The dam in Kilbourn, WI (present day Wisconsin Dells) was originally built in 1859 to regulate water flow for transporting logs through the Dells of the Wisconsin River. Though a modern dam was completed in 1908, flooding remained a natural part of life at the Shack for the Leopolds. Luckily, the location of the Shack on the slope of the Sand Hill meant that marooning and a delayed schedule were the worst consequences of the rising water for Leopold. “There are degrees and kinds of solitude...I know of no solitude so secure as one guarded by a spring flood.”

Though it is often viewed with trepidation, the natural rise and fall of streams and rivers plays a major role in shaping the physical environment and for maintaining ecosystem function. While the threat of a major riverine flood in any given year is small, the location of the marsh within a floodplain creates constraints with regard to project planning and design (pgs. 52–55). Floodplain activities outside of the stream channel are generally regulated by state and local authorities, with regulations aimed at limiting fill or encroachment.

100-year flood

• also known as the regional flood or base flood • annual 1% probability of flooding based on recorded data floodway

• area within floodplain that must carry the base flood • floodplain activity must not increase flood level within the floodway by greater than a designated height (surcharge)

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Great Marsh Soils. (Tenn, 2014)

The Great Marsh is primarily composed of two soil types: Adrian and Houghton muck. Both are characterized by deep, poorly drained organic soils and are unstable with regard to structural development.

Thus, an understanding of subsurface soil conditions is critical to the design of a stable boardwalk foundation. soil survey map

Soil Classification While the iconic “Sand County” is not actually represented by physical or political boundaries, the name is certainly not a misnomer for the areas surrounding Aldo Leopold’s shack. The Leopold Memorial Reserve (LMR) is located within the Central Sand Ridges ecological region and adjacent to the Glacial Lake Wisconsin Central Sand Plains ecological region. The dry, sandy, and loamy till of the Sand Ridges and the sandy outwash of the Sand Plains are characteristic of soils in southwest Wisconsin’s stream bottom and forested, sandy soil regions (pg. 23).

County soil surveys from the Natural Resource Conservation Service (NRCS) provide a good representation of soils found within the LMR and are important tools for identifying soil properties and limitations with regard to land use. The Great Marsh contains two primary surface soil types, Adrian and

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Houghton muck. Muck soils are rich in organic materials, highly compressible, and exhibit low shear strength. Thus, they are considered unstable and generally unsuitable for development. Given that the depth to bedrock in the region is greater than 100 feet, an understanding of the depth of the surface organic soils and the underlying subsurface soil layers is imperative for boardwalk foundation design.

Soil surveys are based on models developed from observations of related geology, landforms, relief, climate, and natural vegetation. While they are fairly accurate, physical observations for any given location are necessarily limited due to the scale and breadth of coverage. For many projects, further site investigations are necessary in order to corroborate soil surveys and to provide more detailed information specific to ...continued on page 22

Wetland Soil Classifications

Other Adjacent Classifications

Ad: Adrian muck • slope: 0–2% • landform: shallow closed depressions of outwash, till, lake (relict), and flood plains; lake terraces, moraines • parent material: organic deposits over sandy outwash • typical profile: muck—sand • natural drainage class: very poorly drained

BrA: Brems loamy sand • slope: 0–3% • landform: acid sandy outwash on outwash plains, lakebeds, stream terraces, and moraines • parent material: outwash sand deposits • typical profile: loamy sand—sand • natural drainage class: moderately well drained

Ae & Af: Alluvial land, sandy, & Alluvial land sandy, wet

GoB & GoC: Gotham loamy sand

• • • •

• • • • •

slope: 0–2% landforms: valleys, flood plains, depressions parent materials: sandy glaciofluvial deposits typical profile: loamy sand—stratified sand to loam (Ae) or loamy sand—stratified sand to loamy fine sand (Af ) • natural drainage class: somewhat poorly drained (Ae) or poorly drained (Af )

Fu & Fw: Fluvaquents & Fluvaquents wet

• slope: 0–2% • landform: flood plains, drainageways, depressions (Fw) • parent material: silty to sandy alluvium over stratified sandy and loamy alluvium • typical profile: variable • natural drainage class: somewhat poorly drained (Fu) or poorly drained (Fw) Gr: Granby Loamy Sand

• • • • •

slope: 0–2% landform: depressions, flood plains, lakebeds (relict) parent material: sandy outwash typical profile: loamy sand—sand natural drainage class: very poorly drained

Ho: Houghton muck • slope: 0–2% • landform: depressions on lakebeds (relict), outwash plains, ground moraines, floodplains • parent material: organic deposits >51 inches thick • typical profile: muck • natural drainage class: very poor • farmland of statewide importance ShA: Shiffer variant sandy loam • slope: 0–3% • landform: drainageways or depressions on outwash plains or stream terraces • parent material: loamy to sandy alluvium over sandy outwash • typical profile: sandy loam—loamy sand—sand • natural drainage class: somewhat poor in loamy deposits; rapid in underlying sandy layers • prime farmland (if drained)

slope: 1–6% (GoB) or 6–12% (GoC) landform: stream terraces, outwash plains parent material: deep sandy outwash deposits typical profile: loamy sand—loamy fine sand—fine sand natural drainage class: well drained

Pd: Pits gravel

• slope: no classification • parent material: gravelly outwash • typical profile: stratified extremely gravelly coarse sand to very gravelly sand PfB, PfC, & PfD: Plainfield loamy sand, till plain

• slope: 1–6% (PfB), 6–12% (PfC), or 12–30% (PfD) • landform: till plains, outwash plains, & moraines • parent material: sandy drift on outwash plains, valley trains, glacial lake basins, stream terraces, moraines and other upland areas • typical profile: loamy sand—sand • natural drainage class: excessively drained WxB: Wyocena sandy loam

• • • • •

slope: 2–6% landform: ground and end moraines, till plains parent materials: sandy till typical profile: sandy loam—loamy sand—gravelly sand natural drainage class: moderately well drained in loamy subsoil; rapid drainage in sandy subsoil • prime farmland (all areas) WxC2 & WxD2: Wyocena sandy loam, eroded

• • • • • •

slope: 6–12% (WxC2) or 12–20% (WxD2) landform: till plains, moraines parent material: sandy till typical profile: sandy loam—loamy sand—sand natural drainage class: well drained farmland of statewide importance (WxC2 only)

Legend: classifications along boardwalk route adjacent classifications

farmland soil classification

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the work planned. Engineering foundations appropriate for soils of the Great Marsh is an example.

A subsurface soil analysis for the marsh was conducted in September of 2014. An all-terrain drill rig was brought to the marsh to determine the depth of surface organic soils and to sample subsurface soils.

Wet soil conditions limited sampling with the drill rig to the edge of the marsh. Two 15 foot soil cores were taken—one at each end of the proposed boardwalk route. As conditions allowed, manual bucket auger samples were taken at points deeper within the marsh, also along the proposed route. In an attempt to locate areas with possible subsurface soil variation,

sample sites were chosen primarily based on differences in surface vegetation. In addition to on-site observations, samples of surface and subsurface soils were taken for laboratory testing.

Results of the analysis corroborated the sandy nature of the region’s soils. Interestingly, a clay soil layer of varying thickness was found beneath the organic surface at varying depths. This layer overlays deeper loose and fine sands. Testing also revealed important information pertaining to the characteristics of subsurface soils and soil profiles that has allowed independent consultants to provide more accurate assessments of structural design requirements and pricing.

ATV Drill Rig in Marsh (Tenn, 2014)

Marsh Soil Core (Tenn, 2014)

An all-terrain drilling rig was utilized to sample soil within the Great Marsh. While mechanical sampling was limited due to the wet conditions, soil profiles reveal positive results with regard to the use of deep foundations such as helical or driven piles that would bear on subsurface soils.

Great Marsh soil sampling

Geotechnical Analysis Summary General info

• Nummelin Testing Services, Inc. (Stevens Point, WI) • date of testing: September 16, 2014 Sampling information

• manual boring: 4 w/ bucket auger to 2–6 feet; one Shelby Tube sample of organic surface soils was recovered • mechanical boring: 2 with drilling rig to 15 feet Sampling results

• water depth: 0-2 feet • typical mechanical boring profile: organic—sand—medium to very stiff clay—loose fine sand • typical manual boring profile: organic—medium clay— loose fine sand • max observed depth of organic materials: 4 feet

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• unconfined compressive strength test of the recovered organic surface soil sample was determined to be 200psf • presumptive bearing capacity for foundations bearing on inorganic soils: 1500psf Report Recommendations

• foundation types bearing on organic soils not recommended • foundation types should bear on inorganic subsurface soils (e.g. post/pier, helical, displacement/driven) with minimum bearing width of 4 inches and embed a minimum of 5 feet into inorganic materials (starting at max scour depth); total settlement expected is 1 inch • organic materials provide little lateral support; slender foundations (e.g. helical piers) should be designed to account for potential buckling • corrosion protection recommended

51c. Glacial Lake Wisconsin Sand Plain

Leopold Center

area of detail

51d. Central Sand Ridges

53c. SE Wisconsin Savannah and Till Plain

52d. Coulee Section

52a. Savannah Section

Ecological Landscapes of Wisconsin (WI DNR, 2014)

Ecoregions contain assemblies of ecosystems within a geographically defined area. The LMR sits within the Central Sand Ridges but also near the boundary of three other level IV classifications: the Glacial Lake Wisconsin Sand Plain; the Coulee Section; and the southeastern Wisconsin Savannah and Till Plain.

Wisconsin ecoregions

Leopold Center area of detail Legend C. Forested, sandy soils (central WI) C. Streambottom and major wetland soils Cm. Prairie, sandy soils B. Forested, silty soils (southeastern WI) A. Forested, silty soils (southwest WI) Soil Regions (WI DNR, 2014)

Soils regions contain soils grouped within similar taxonomic classifications. The soils of the LMR are located at the cusp of three regions and likely exhibit characteristics from each: forested silty soils, stream bottom and major wetland soils, and forested sandy soils.

Wisconsin soil regions

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Great Marsh Wetland Classification (Tenn, 2014)

Wisconsin’s Wetland Inventory is created using stereoscopic black and white infrared aerial photographs. Each mapping unit represents a delineation having a single classification.

Mixed classifications (e.g. T3/E1K) are used when different cover types represent at least 30% of the area.

wetland inventory map

Wetland Classification & Permitting Though the extent and degree to which wetlands provide services is unique, wetland functions are critical to both humans and wildlife. They range from the provision of habitat and enhancing water quality to mitigating the impact of flooding and limiting shoreline erosion. They also provide areas within which to recreate and appreciate the beauty of nature.

Technical definitions vary slightly, but three factors are common to all wetlands: wetland hydrology; hydric soils; and hydrophytic vegetation. Delineating and protecting wetlands is the responsibility of the U.S. Army Corps of Engineers (USACE) and is based on EPA guidelines and provisions within Section 404 of the Clean Water Act. Within Wisconsin, the Department of Natural Resources (DNR) and local authorities work with the USACE to oversee development that might impact wetlands.

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Given the desire to preserve the culturally and environmentally significant marsh landscape, the status of much of the Great Marsh as a wetland is not in question. Thus, delineating precise wetland boundaries for the boardwalk project is unnecessary. However, if the project is deemed to cause a net loss in wetland function (e.g. through the addition of fill materials), permitting may be required. Ultimately, the manner in which the boardwalk is designed can significantly influence permitting requirements.

The question of permitting primarily influences the design of boardwalk foundations. Certain deep foundations that limit environmental impact (e.g. helical piles and some driven pile systems), may not be regulated as fill and, thus, would not be subject to certain permitting requirements. However, this decision must be made by the appropriate regulatory

Forested Wetlands (T3K, T3Kw, T3/E1K) • Forested (T3): broad-leaved deciduous trees of greater than 20 feet in height (e.g. black ash, elm, and silver maple) • Palustrine, wet soils (K) without prolonged periods of surface water • Seasonally flooded (w) forested wetlands associated with the Wisconsin River floodplain complex are found near the Birch Row trail.

Forested Wetlands in Marsh (Tenn, 2014)

Emergent/Wet Meadows (E1K, E2K & E2H) • Emergent Wet Meadows (E) with herbaceous plants which stand above the surface of the water • Plant remains are persistent (1) into next growing season and are grass-like/narrow (2) • Palustrine (K) soils or standing water (H) for much of growing season may be present.

• Reed canary grass is found within the marsh to varying degrees.

Emergent/Wet Meadows in Marsh (Tenn, 2014)

Scrub/Shrub (S3/E1K & S3/E2K) • Scrub or shrub (S) comprised of woody, broad-leaved deciduous vegetation of less than 20 feet in height (e.g. willows, alder, young green ash) • Broad leaf deciduous shrubs other than tamarack (3) are present.

• Generally found along the edges of woodlands and higher/drier areas and pond berms • Palustrine soils (K) (no standing water for prolonged periods) Scrub Wetlands in Marsh (Tenn, 2014)

Open Water (W0H & W0Hx) • • • • •

Lakes and ponds with water depth of 6 feet or less (W) Many have been artificially excavated (x).

Subclasses unknown (0); bottom characteristics of ponds are largely undetermined.

Palustrine systems with standing water (H) The boardwalk is not presently routed over any open water.

Open Water Wetlands in Marsh (Tenn, 2014)

agencies. In that regard, a preliminary permitting meeting regarding the boardwalk project was held with representatives from the USACE, WI DNR, and Sauk County on May 07, 2014.

The issuance of Section 404 individual permits by the USACE requires a stringent review process that considers viable alternatives and the impact of development and would result in a requirement for compensatory mitigation (e.g. via restoration, creation of new wetlands, or programs such as mitigation banking). Many projects, however, are reviewed under national or regional Section 404 general permitting procedures. Wisconsin’s regional general permit (WI-GP-002) imposes maximum allowable impacts up to which a Section 404 individual permit is not needed: less than 10,000 square feet of impact falls under a recreation category; no more than 2 acres is

permissible with a Letter of Permission and subject to a period of public comment. Similarly, the Wisconsin DNR has established criteria for processing its own wetland individual and general permits.

Components of the Classification System (WI DNR, 1992)

components of classification system WI DNR classification codes are based on the U.S. Fish and Wildlife Service “Classification of Wetlands and DeepWater Habitats of the United States.”

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Leopold Shack

E

Great Marsh

Leopold Center A

D D

C

B

“Great Marsh” Boardwalk Route (Tenn, 2014)

Amongst other things, the route between the Leopold Center and Leopold Shack considers potential viewpoints, aesthetic and experiential qualities, limiting site disturbance, and avoiding open water. Nodes were chosen to highlight points of interest such as shifts between plant communities. proposed boardwalk route

Boardwalk Route & Trails The proposed Great Marsh boardwalk route bridges the gap between recreational trails adjacent to the Leopold Center and Leopold Shack. Presently, limited infrastructure along Levee Road does not make for a safe or comfortable pedestrian corridor, and the extension of existing trails into the marsh would prove fruitless from the time of the spring thaw until the ground freezes in late autumn or winter. Routes bypassing the marsh to the south would likely be underutilized given their length and possible time and/or physical constraints faced by visitors.

Attempts were made to minimize the route’s distance while maintaining the integrity of the wetland environment and maximizing user engagement with the marsh landscape. Where possible, the route tracks over areas inundated with invasive reed canary grass,

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rather than desirable sedges. Previously disturbed sites along existing man-made ponds are also prioritized.

These areas provide vantage points within the flat landscape and offer ample room for gathering spaces and interpretive elements.

Overall, the route highlights points of interest, emphasizes environmental changes for interpretation, and also attempts to create a sense of anticipation. For instance, exiting the marsh enveloped in mottled sunlight and under a comfortable canopy of ash, birch, and maple trees creates a quiet place for reflection prior to visiting the pines along Birch Row and seeing the Shack. This segment also avoids a longer path along Levee Road that would have increased visibility from the Shack—something that may be undesirable from the standpoint of the historic site.

A

Aldo Leopold Memorial Site

Aldo Leopold Memorial Site Plan (Tenn, 2014)

B

The Aldo Leopold Memorial commemorates the approximate spot where Aldo Leopold succumbed to a heart attack while fighting a grass fire. It recognizes the legacy of conservation established by the Leopold family while also acknowledging the push and pull that exists between Leopold’s concept of the land as a community and the individual understanding of our obligations toward that community, our Land Ethic. Adjacent to the Leopold Center, the memorial will provide visitors with a culminating experience and a place of rest and reflection after visiting the Leopold Shack and Farm and exploring the trails and landscapes of the Leopold Memorial Reserve.

Development is slated to begin in 2015.

Rain Garden Trail Segment

Rain Garden Connecting Trail Segment (Tenn, 2014)

C

Behind the Leopold Center, a rain garden allows stormwater funneled via an aqueduct from the center’s roof to more slowly infiltrate into the ground. Over time, an informal footpath around the rain garden has been created by visitors making their way to the nearby trails. With the help of volunteers, this path was recently renovated to ensure a more pleasurable aesthetic and walking experience. A new trail segment that more directly links the rain garden to the more extensive trail network was also constructed.

In the future, a portion of this trail will connect the Leopold Center to a nearby intern and guest house—the Future Leaders Center—that is currently in the design and planning phases.

Upland Trail Segment Adjacent to the Great Marsh, a portion of the ALF’s existing trail network ventures onto neighboring property. In order to provide a more direct route to the boardwalk while bypassing this low-lying area, an upland trail was recently constructed. Site analysis using geographic information systems technology and preliminary wetland delineation ensured that the trail avoided the floodplain and wetlands and would remain passable throughout the year. Strategic openings in the understory were created to provide views of the marsh and a sense of anticipation. As with the rain garden segment, volunteers played a significant role in development of the trail.

Upland Trail Segment in Progress (Tenn, 2014)

D

Rest and Activity Nodes

Second Pond Berm in Marsh (late spring) (Tenn, 2014)

E

Many locations along the route to the Shack are suitable for interpretive or reflective activities and/or gatherings. Given the length of the trip (over one mile in each direction) and lack of cover within the marsh, formal areas for rest should also be provided. The boardwalk might strategically utilize the north side of the trees in the marsh to offer visitors areas for seating and relief from the sun. The pond berms also provide elevated vantage points relative to the rest of the marsh and may accommodate larger gathering areas. Even if no such space is immediately planned, maintaining a route that parallels the pond edge would allow space for future deck development (pgs. 56–57).

Levee Road Intersection

Levee Road Near Route Intersection (Tenn, 2014)

When Levee Road was paved in 1977, disagreement existed between Fairfield Township and the L.R. Head Foundation about its modernization. Ultimately, inclusion in Wisconsin’s Rustic Roads program helped to preserve features such as the Sand Hill—the location of the Good Oak. Considering the proposed boardwalk route, an appropriate street crossing will be necessary where it meets the Birch Row trail at Levee Road. Termination of the boardwalk prior to meeting the road would require that pedestrians climb its shoulder to cross. If a level crossing is desired, coordination with the township and county will be necessary to implement any necessary infrastructure (e.g. a culvert) and/or signage within the road easement.

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Budget Scope and Overview To connect the existing trail system surrounding the Leopold Center with the historic Aldo Leopold Shack and Farm, the Great Marsh Boardwalk will span approximately 3000 feet within a floodplain wetland. Selection of the route was determined upon consideration of a number of factors, including distance, property boundaries, physical obstacles or barriers (e.g. large bodies of water), existing sites of disturbance within the marsh, viewsheds, and opportunities for environmental and cultural interpretation.

While there are relatively few architectural elements to consider when compared with more complex structures, a number of environmental, social, and economic factors create challenges for the project. This section provides a synopsis of budget analyses and offers potential cost scenarios associated with the proposed development. Though economics will have considerable weight on the path forward, the document also elaborates on some of the opportunities and constraints associated with the project’s broader planning and design goals.

At this stage, a number of functional and aesthetic details remain unresolved, and specific design elements are unavailable for pricing. However, general architectural and engineering principles have been considered, and numerous completed projects, trade documents, and experienced professionals have been consulted in order to make calculated and detailed

assumptions about some likely project scenarios.

Thus, the analyses represented here may offer greater insight into cost than some preliminary estimates.

Cost is examined by delineating the project into four major components: foundations; decking; guardrails and curbs; and substructure/framing. Structural, environmental, and aesthetic considerations are briefly examined for each component. Additional features that may be desirable but are unnecessary for the basic structure (e.g. viewing platforms or decks, interpretive signage, seating) are included in budget scenarios but examined more generally. Whenever possible, component costs are described on a per linear-deck-foot basis to allow for extrapolation of cost based on various lengths of boardwalk. Except where noted, labor costs are not derived for individual components and are included, along with soft costs (e.g. design), in budget scenarios at the end of the document.

Ultimately, there will be many combinations of materials and techniques that are able to achieve the desired aesthetic, structural, functional, and experiential goals of this project. While these analyses are necessarily limited to a few scenarios, they provide insights that should help clarify the overall vision for the Great Marsh Boardwalk and will assist in making informed decisions about detailed design and pricing scenarios, as well as in selecting project consultants and contractors once such a stage is reached.

Approximate Budget Variation: $175,000–$315,000

• 4 foot deck width, basic materials, pan-style foundations • volunteer-led or contractor installation • curbs and basic railings along 45% of route $370,000–$777,000

• 6 foot deck width, basic materials • shallow and deep foundation options • basic and upgraded railing options along 45% of route $750,000–$1,000,000+

• 6 foot or greater deck width; greater material choice • deep foundations systems (helical piles) • greater material and aesthetic options available for railings along 45% of route Boardwalk Conceptual Rendering (Tenn, 2014)

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Components of Estimates

Horicon Marsh Boardwalk Deck (Tenn, 2014)

Jester’s Creek Path, Morrow, GA (Helical Pile World, 2011)

Foundations The floodplain and wetland environments of the Great Marsh warrant careful consideration with regard to the boardwalk foundation selected. Detailed analyses were conducted for one shallow and one deep foundation system: pan footers produced by Custom Manufacturing (shallow) and helical piles (deep) in general. For the former, discrete pricing is provided by the manufacturer. For the latter, precise estimates will be unavailable until design details are better defined. However, pricing of helical piles was based upon assumptions about design derived from known information about site conditions, a completed geotechnical analysis, and consultation with contractors and engineers familiar with the systems.

Decking Great variety exists with regard to decking material selection. Even within a single category, variation in material quality and size can have a great impact on overall design, cost, and longevity. Thus, analyses certainly do not cover all possible options, but materials were selected to provide an overview of price variation between some of the more common standard and premium options. Additionally, comparisons within categories were utilized to determine systems that could provide greater economic efficiency. In all instances, only grades of specific materials (e.g. #2 prime ACQ or CA pressure treated southern yellow pine) meeting quality standards for the specific purpose were considered.

Cable Railing Around a Pool (American Metal Specialties, n.d.)

Guardrails Given their visual prominence, as well as their role in enhancing the overall user experience, guardrails should be viewed as more than simply utilitarian safety features.

Options for design are nearly limitless, and, as with decking, analyses were intended to provide a broad overview of pricing. Regardless of chosen aesthetic, these features should conform to basic safety standards as set forth by the International Building Code (IBC) or by the American Association of State Highway and Transportation Officials (AASHTO). While some ambiguity exists with regard to their applicability for recreational trails, careful consideration of these standards can lead to significant cost and time savings.

Solid Post Attachments With Threaded Rod (Ellis, 2014)

Substructure/Framing If built sufficiently and properly, the beams and joists comprising the deck framing should hardly be noticeable to guests, except in so far as they sustain a beautiful and comfortable walking surface. Primary considerations include material and spacing requirements for defined loads. With that in mind, framing and foundations are inextricably linked and any changes to one can result in changes to the other. Two readily available materials (southern yellow pine and douglas fir) were considered in various configurations based on International Residential Code (IRC) and American Wood Council standards. Should it be warranted, additional structural support (e.g. for maintenance vehicles) would comprise a relatively inexpensive addition.

Horicon Marsh Viewing Platform/Deck (Tenn, 2014)

Additional Features & Soft Costs Beyond the primary walking route, one or several stopping points of varying size will be desirable to provide opportunities for rest, interpretation, and/or convening.

Interpretive signage and mechanisms for wayfinding should also be thoughtfully considered. Such costs, however, were isolated from the above components so as not to skew interpretation of general costs associated with the basic design elements. In that regard, allowances for small viewing platforms, signage, and seating were included in budget scenarios at the end of the document. Deck allowances were based on per linear-deck-foot prices, but not included in them. Some estimates for soft costs were also provided in final budget scenarios.

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Estimates Custom Manufacturing® The proprietary shallow foundation system developed

by Custom Manufacturing (Clinton, WI) is comprised of beveled square metal pans to which structural wooden posts are attached. The pans sit atop the desired surface and distribute loads as would other spread footings or floating foundations.

Framing and decking systems are modular in nature and available in 8 foot long segments of varying width (4, 5, or 6 feet). Two 4 foot wide segments can be combined with additional footers to create an 8 foot wide deck. All segments are built of pressure treated pine and come pre-assembled. Horizontal and vertical railing “kits” are also available for sale.

Due to the system’s relative simplicity, the company touts the opportunity for self-installation.

Nearby examples of non-contracted installation exist (e.g. Horicon Marsh), and a coordinated volunteer development effort with the Ice Age Trail Alliance and National Park Service has been discussed. While such an effort may be desirable for a number of reasons,

it also has significant drawbacks. Namely, efforts can be greatly protracted for such large projects, and the potential cost savings diminish when one considers inherent overhead costs associated with volunteer coordination. Quality control is also a concern, and self-installation should not preclude the need for professional consultation and guidance.

The primary benefit of the system is its potential low cost. At its high end, the cost of this system overlaps other methods discussed later. Unfortunately, comparison between this and other systems is not necessarily equivalent. The vast majority of savings are derived from the foundation, but concerns over the suitability of shallow foundations on unstable organic soils and within variable hydrological conditions exist.

A small sampling of relatively new projects are available at precedent, but visitation has raised concerns with structural stability and settling. While latitude exists for their alteration, standard components might not meet the quality of design and materials necessary to achieve desired aesthetics, factors of safety, and/or to accommodate alternate usage. Any enhancements will increase price points.

Completed Boardwalk, unknown location (Custom Manufacturing®, n.d.)

Custom Manufacturing Pan Footers (Custom Manufacturing®, n.d.)

Pros:

Cons:

• • • •

• structural concerns (e.g. sagging, heaving/uplift, general stability) with regard to site soils and hydrology • questions about durability and short- and long-term maintenance costs; adjustments to foundations are possible but labor intensive and may degrade integrity of materials • potential for inflated costs relative to estimates depending on desired structural and/or aesthetic enhancements • likely considered fill by regulatory agencies (increased permitting lead time and possible mitigation requirements)

significant savings possible relative to other systems prefabricated modular components some adjustments to design are possible ability to directly involve volunteers (positive w/ regard to outreach and building partnerships with other organizations; this could also be negative when considering cost, logistics, and quality control associated with volunteer coordination)

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Custom Segment with Submerged Foundations (Tenn, 2014)

Typical Panel Layout (Custom Manufacturing®, n.d.)

Deck segments consist of 8 foot long frames in widths of 4, 5, or 6 feet (8 foot widths are achieved by joining 4 foot segments). Frames are joined by brackets along headers at each post. Design specifications listed on the company website assume a 1500psf soil bearing capacity. The marsh geotechnical analysis revealed surface soils with a compressive strength of 200psf. Similar soil conditions were encountered at Horicon Marsh (above) and resulted in structural settling and sagging.

Additionally, rather than being supported by fasteners alone, beams/headers should bear directly on posts.

Custom Manufacturing® boardwalk schematics

Deck Dimensions

Decking

width (ft) 4 5 6 8

4'x8' panel 5'x8' panel 6'x8' panel 2x 4'x8' panels

Curbs 2"x4" Curb Kit 2"x6" Curb Kit 2"x8" Curb Kit

Railing Kits Horizontal Vertical

Pan footers 4'–6' width 8' width

dimensions 15-1/2" x 15-1/2" 19-1/2" x 19-1/2" 15-1/2" x 15-1/2" 19-1/2" x 19-1/2"

Installation (price range)

segment length (ft)

3000

8

length (ft)

segment length (ft)

3000

8

length (ft)

segment length (ft)

3000

8

length (ft)

segment length (ft)

3000

8

units 375 375 375 750

per unit (each) $220.00 $250.00 $265.00 $220.00

units 375 375 375

per unit (each) $44.00 $50.00 $60.00

total $16,500.00 $18,750.00 $22,500.00

per foot $5.50 $6.25 $7.50

375 375

per unit (each) $200.00 $444.00

total $75,000.00 $166,500.00

per foot $25.00 $55.50

per unit (each) $58.00 $68.00 $58.00 $68.00

total $43,616.00 $51,136.00 $65,424.00 $76,704.00

per foot $14.54 $17.05 $21.81 $25.57

total $120,000.00 $240,000.00

per foot $40.00 $80.00

segments 376 376 376 376

units/segment 2 3

length (ft) 3000 3000

low estimate high estimate

Summary (estimates)

Cost

length (ft)

units 752 752 1128 1128

per unit (ft) $40.00 $80.00

total per deck foot $82,500.00 $27.50 $93,750.00 $31.25 $99,375.00 $33.13 $165,000.00 $55.00

Description materials only installed ($40/ft) installed ($60/ft) installed ($60/ft) installed ($80/ft)

note: all estimates assume use of 19-1/2" sq pans 2x4 curbs kits only, no railings 2x4 curbs kits only, no railings horizontal railings (45% of length), 2x4 curb kits (55% of length) vertical railings (45% of length), 2x4 curb kits (55% of length) vertical railings (100% of length)

total $150,136.00 $269,761.00 $356,461.00 $397,636.00 $540,136.00

per deck foot $50.05 $89.92 $118.82 $132.55 $180.05

5' boardwalk

materials only installed ($40/ft) installed ($60/ft) installed ($60/ft) installed ($80/ft)

2x4 curbs kits only, no railings 2x4 curbs kits only, no railings horizontal railings (45% of length), 2x4 curb kits (55% of length) vertical railings (45% of length), 2x4 curb kits (55% of length) vertical railings (100% length)

$161,011.00 $281,011.00 $367,711.00 $408,886.00 $551,386.00

$53.67 $93.67 $122.57 $136.30 $183.80

6' boardwalk

materials only installed ($40/ft) installed ($60/ft) installed ($60/ft) installed ($80/ft)

2x6 curbs kits only, no railings 2x6 curbs kits only, no railings horizontal railings (45% of length), 2x6 curb kits (55% of length) vertical railings (45% of length), 2x6 curb kits (55% of length) vertical railings (100% length)

$167,011.00 $287,011.00 $374,573.50 $415,748.50 $557,011.00

$55.67 $95.67 $124.86 $138.58 $185.67

8' boardwalk

materials only installed ($60/ft) installed ($60/ft) installed ($60/ft) installed ($80/ft)

2x8 curbs kits only, no railings 2x8 curbs kits only, no railings horizontal railings (45% of length), 2x8 curb kits (55% of length) vertical railings (45% of length), 2x8 curb kits (55% of length) vertical railings (100% length)

$257,829.00 $377,829.00 $467,829.00 $509,004.00 $648,204.00

$85.94 $125.94 $155.94 $169.67 $216.07

4' boardwalk

The above table represents scenarios and pricing schemes for the Custom Manufacturing system.

For each deck width shown in the summary table, the first and fifth estimates represent the lowest and highest priced options, respectively. Due to the likely utilization of professional installers/contractors and the need for railings along portions of the boardwalk route, the 3rd and 4th rows within each category represent the most probable estimates.

Custom® estimate

29

Foundations: Helical Piles For a number of reasons, the boardwalk’s foundations is probably the most crucial design element.

Potentially representing the greatest overall project expense, foundations also play a major role in determining allowable use/function, durability, and longevity. Additionally, the location of the boardwalk within a floodplain marsh consisting of widely distributed deep organic surface soils limits options that might be reasonably implemented.

Helical piles (also screw piles or helical piers) represent a cost effective, flexible, strong, and durable option that will also limit the physical impact on the surrounding environment relative to other deep foundation systems. This technology has a long historical track record, having been originally developed in the 19th century to moor ships and later utilized to support light house foundations. Lacking mechanized installation methods, other foundation systems overtook them in popularity, but the last few decades have seen a resurgence in the popularity of helical piles for a number of applications.

Like an Archimedean screw, the piles are comprised of a central shaft with one or more plates wrapped around it (as a helix). The size and shape of the shaft, as well as the size and spacing of the plates, are engineered to accommodate design loads in the specific substrate or soil in which the foundation is installed.

Helical piles are versatile and can act in either tension or compression, can be driven great distances to attain suitable conditions, can be installed in confined areas, limit disturbance, and given continued advances in engineering can be utilized for ever more robust purposes and within a greater number of site conditions.

A recently completed geotechnical analysis revealed that organic surface soils of the Great Marsh are underlain by various sandy and clay layers and that helical piles would be suitable for this project.

Given the depth of the organic soils and the height of the boardwalk above the surface, lateral supports will likely be necessary. Other deep piles such as micro- or mini-piles (a driven friction pile) may also be suitable but will be less likely to resist heave/uplift and could prove to be more costly given the need for large equipment during installation.

Maplin Sand Lighthouse: Founded on Mitchell’s Screw Piles (Alexander Mitchell & Son, 1848)

Boardwalk and Walkway Foundation Bracket with Lateral Support System (Hubbell Incorporated, 2013)

Pros

Cons

• strong and durable materials • can support lateral, compressive, and tensile loads • independent of surface soil conditions for structural stability; resist heave and other changes in soils that other driven piles do not always withstand • immediate feedback during installation • can accommodate various frames, design loads, etc.

• utilize small equipment for installation relative to other deep piles (installation by hand or handheld equipment possible in some instances) • low profile and limited disturbance during installation

• high cost compared to pans • will require specific engineering for the site conditions and for lateral stabilization (economy of scale can reduce costs significantly) • requires trained and experienced installers • accurate pricing/estimates are difficult to obtain (information provided in completed geotechnical analysis allows for greater certainty) • not suitable in all soil conditions

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Chance Solid Square Shaft Helical Pile (Danbro Distributors, 2013)

A central shaft and plates provide bearing capacity. An even pitch reduces soil disturbance, and defined spacing between plates ensures that plates bear atop settled soil.

helical pile components

Hand Driven Screw Piles (Reed Hilderbrand, 2011)

The residential boardwalk in Stockbridge, MA sits atop hand-driven helical piles. Designed by Reed-Hilderbrand, the project won an ASLA Honor Award in 2011.

Berkshire boardwalk

Utilization of helical piles can be an expensive proposition but would also provide many benefits. Costs vary depending on materials, project scale, and the final installed depth.

Maximizing the average distance between foundations will greatly decrease overall costs despite necessary increases to framing costs. While an exact price is difficult to determine, consultation with numerous sources has led to an installed price range of approximately $600-$1200 per foundation. For overall budget scenarios, a $900 price point was utilized.

helical pile estimates

31

Decking Materials A boardwalk’s decking is one of its most highly scrutinized components. Given numerous choices with regard to material type, quality, size, and aesthetics, as well as necessary accommodations for desired functionality, decking costs can vary greatly.

However, even a modest material choice can represent a significant expense for a large project. Nonetheless, the boardwalk deck will have a significant impact on user experience. Therefore, it is important to consider how appropriate design can manage costs while also accounting for pedestrian circulation and safety, possible vehicular traffic, durability and maintenance, environmental impacts, and aesthetics.

The selection of an appropriate decking material is certainly not made easier by the plethora of choices offered in the market: traditional domestic lumber (e.g. pressure treated, rot resistant), exotic and domestic hardwoods (e.g. ipe or black locust), composite materials (e.g. Trex® Azek®, TimberTech®, UltraDecK®, and so on), 100% recycled plastics (e.g.

Axion®), steel, aluminum, and even fiberglass.

A selection of these materials was analyzed for cost within 4, 6, and 8 foot deck widths. Generally, decking costs were found to correlate linearly with deck width. As the 6 foot width represents a dramatic functional improvement over a 4 foot deck, it was chosen as the standard by which all boardwalk components are compared within this text. For decking specifically, it is worth noting that cost efficiency of board sizes (e.g. 2x4 vs. 2x6, etc) varies by material.

However, in many instances larger boards are more cost effective and can be more aesthetically desirable.

All estimates include assumptions for hardware costs. A fixed number of galvanized deck screws (two per board per joist) were included. For simplicity and because joist spacing has not yet been determined, this number was based on a blanket joist spacing scenario.

If applicable, specialty screws (e.g. those necessary for composite materials) or fastener systems (e.g. hidden) were also included. In general, pressure treated lumber such as southern yellow pine and some naturally decay resistant lumber (e.g. cedar) represent the most economical options. More detail about material types are presented on the following page.

Design Considerations • materials: quality, size, color/finish, availability, cost • longevity/durability and maintenance requirements • ease and cost of installation (e.g. pre-drilling requirements, expensive hardware or fastener systems) • deck width, accessibility (present and future) • environmental considerations (e.g. pressure treatment chemicals, source materials)

Figure A1: Minimum Passage Width for One Wheelchair and One Ambulator Person (US Dept of Justic, 2010)

• aesthetics: finish, weathering, size of boards, cuts for accommodating curves, surface texture, other special features (e.g. picture-framing, diagonal decking) • gaps/spacing (light penetration below deck) • being mindful of decking span and manufacturer recommendations (i.e. joist layout), especially with specialty products such as composites

Figure A2: Space Needed for Smooth U-Turn in a Wheelchair (US Dept of Justic, 2010)

Often associated with wheelchair users, it is also important to consider how designing for accessibility can positively impact all user groups. Consider accommodating multiple individuals in passing, visually impaired persons utilizing guide canes, those with pets, strollers, young children, the elderly, vehicles, or any situation which may require additional maneuverability. design for accessibility

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Pressure Treated Pine Decking (Tenn, 2013)

Pressure Treated (PT) Southern Yellow Pine (SYP) Many methods of chemical wood preservation have been developed and can be applied to various types of lumber. With a high proportion of sap wood, yellow pine species are commonly utilized, and #2 graded SYP is an economical solution. Other treated lumber (e.g. hemlock-fir) is more readily available on the west coast. While higher deck-specific grades (e.g. ‘premium’ radius edge) contain fewer defects and are more visually pleasing, boards are more expensive and usually sold in smaller nominal sizes (e.g. 5/4”) that may be prone to warp. It is important to note that many preservatives are corrosive and require the use of hot-dipped galvanized or stainless steel fasteners.

Timber Ridge Trail Boardwalk (Axion Int’l, n.d.)

Black Locust Lumber Deck at George W. Bush Presidential Library (Wolfe, n.d.)

Cedar Decking (Zverina, 2004)

Decay Resistant Lumber The heartwood of some tree species (e.g. cedars, redwood, cypress) contains chemical compounds which provide natural resistance to decay. These compounds also provide aroma and coloration (e.g. red tones in cedar) that is often desirable in application.

Care is needed to maintain these qualities, and treatment with a water repellent is recommended; ground contact and exposure will reduce lifespan. Environmental concerns arise from the fact that old-growth is necessary to attain sufficient heartwood.

Due to expense and a tighter wood grain associated with some species, smaller dimensional lumber (e.g. 5/4”) is often utilized.

Hardwoods (Domestic and Tropical) Hardwoods are very strong, durable, and are naturally decay resistant. Many offer unique and interesting coloration and wood grain that make them an attractive choice.

Though tropical hardwoods (e.g. ipe, cumaru) are widely available, expense remains an issue, and it is important to be aware of concerns surrounding sustainable harvesting. While gaining market traction, sourcing large quantities of domestic hardwoods (e.g. white oak, black locust) can still prove challenging and expensive, especially for larger boards. Additionally, all hardwoods require extra preparation in terms of installation (e.g. predrilling) and will be more labor intensive and difficult to install.

Composites and Recycled Plastics The selection of composite and plastic materials for decking varies widely, with manufacturers offering product lines ranging in quality, color, size/shape, and price. In general, natural fiber composites (including wood-plastic) will be more expensive than PT or decay resistant lumber but less expensive than 100% plastic materials. Additionally, using material-specific hardware (e.g. screws suitable for joining composites to lumber) is recommended. Prior “no maintenance” claims have been limited by variable susceptibility to UV, mold/mildew, discoloration, and physical changes (e.g. expansion & contraction). Susceptibility to fire is also a consideration in this application.

Metal Grate Decking (Huffaker, 2014)

Bar Grating and Welded Wire Mesh Grating produced from galvanized or stainless steel, aluminum, or fiber reinforced polymers can provide a durable and interesting decking alternative. Each has functional and aesthetic strengths and weaknesses, but numerous manufacturing processes (e.g. expanded or swaged) create a wide selection of forms and patterns for consideration.

Depending on specifications (e.g. size, corrosion resistance), grating may still prove cost competitive. Steel connection details also increase complexity and cost. Welding provides the strongest support but also requires an expensive steel substructure. Here, hybrid steel-wood connections utilizing fasteners were assumed for estimates.

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price per linearͲdeckͲfoot

$0

$10

$20

$30

$40

$50

$60

$70

$80

$90

$100

$110

$120

$130

$140

Pressure Treated

Southern Yellow Pine

2x8

5/4x8

1x5.5

Cedar

2x10

2x4

5/4x4

board sizes (nominal)

Redwood (construction common) Decay Resistant

2x12

2x6

5/4x6

Redwood (heartwood)

Select

Material Categories

Trex Composite

Transcend

Black Locust

Wht Oak (qtr sawn) Hardwood

Wht Oak

Ipe

option over pretreated lumber, because not all grades are suitable for exterior applications. Composite and recycled materials are more expensive but quality and price can vary considerably within and between brands. They may also require the use of specialized hardware and depending on their material makeup will still be subject to various forms of decay. Hardwoods can make a beautiful deck but can be quite expensive. Domestic materials can be difficult to source in consistent sizes and in the quantity necessary. However, they may be more desirable than imported tropical hardwoods due to the nature of the project and concerns with sustainability.

Enhance

In general, pressure treated lumber and other softwoods provide the least expensive options. Care should be taken when selecting a decay resistant

Decking prices will vary depending on the specific material type, quality, finish, and size. All estimates below consider a six foot deck width and include galvanized hardware for anchoring to framing. Utilization of hidden fastener systems requires grooved boards and additional labor and can add approximately 10-30% to overall costs. Installation costs are not included here but are factored into budget scenarios at the end of the document.

decking estimates: lumber and composites

35

price per linearͲdeckͲfoot

$0

$25

$50

$75

$100

$125

$150

$175

$200

$225

$250

$275

Expanded (galvanized)

square (2x2)

resin (TͲbar)

resin (IͲbar)

aluminum (flush bar)

aluminum (TͲbar)

aluminum (IͲbar)

aluminum (rect. bar)

stainless steel

galvanized

Material Categories

Fiberglass Resins

pultruded

molded

The relationship between decking and framing is also a key consideration when selecting grating. Different manufacturing processes (e.g. swaging, welding, riveting, etc) impart varying degrees of strength and/or stiffness, and the number and layout of joists may need to be adjusted. Choosing standard sizes will also likely reduce costs. Anchoring these materials to the framing can also be achieved by a number of means. While field welding can provide a stronger connection than anchoring hardware, it would require more costly metal framing, additional labor, and galvanization after welding to protect welded joints from corrosion.

swaged rectangular bar press locked (galvanized) (aluminum) Metal Grating

welded bar (galvanized)

material specifications

With greater porosity relative to other decking materials, metal or fiberglass grating can enhance light infiltration (for plants and wildlife) and visibility to surfaces below the deck. This porosity may also reduce potential impacts of uplift and loading (e.g. with snow). The materials are also highly durable and come in a variety of patterns, colors, and finishes that can add unique aesthetic qualities to the boardwalk. When considering grating, it is important to understand future use. Certain forms/patterns may not be suitable for wheeled or vehicular access and may be uncomfortable for pedestrians (e.g. using walkers or canes).

bar grating and welded wire

Substructure/Framing Boardwalk framing closely parallels traditional deck framing and is comprised of beams/headers and joists/stringers, and any associated hardware. Its primary function is to transfer loads from the deck to the foundation while providing support for mounted objects such as guardrails, signage, or seating.

Framing layout is relatively simple. Beams of varying size span a prescribed distance between foundations and should rest atop the bearing post using a notched post or bracket configuration. Anchoring beams to the side of a post can damage the wood and eventually shear the connections. Joists then span the distance between beams and may be flush/face mounted or mounted atop beams in a dropped configuration. The addition of blocking between joists provides rigidity and helps to counteract twisting.

Design loads and the distance between foundations have significant impact on joist size or span, spacing, and, ultimately, beam specifications. As joist spans increase so do the loads carried by each joist. These loads are ultimately transferred to beams. Because joists act in combination to support a load, increasing the size of the joists will decrease the number of joists necessary and increase the spacing between them.

However, this does not occur in a linear fashion, and increasing the joist span does not necessarily increase cost for a given deck width. Once a joist span and

spacing are established, suitable beams for the given deck width may be selected.

Here, pressure treated southern yellow pine (PT SYP) was the primary material considered for framing. Costs for untreated Douglas fir are approximately 15–25% lower than PT SYP, but untreated lumber is, in general, not recommended for exterior structural applications. In fact, some jurisdictions mandate the use of treated lumber for framing. Composite materials or plastics are sometimes utilized in framing, but many have reduced strength compared to lumber; and composite decking details often incorporate lumber framing. Steel framing is a durable options but is very expensive; a single sample utilizing C-channel beams is included in estimates for reference.

Costs for joists are more substantial than for beams primarily due to the quantity of members and mounting hardware. The addition of beam-to-post attachments (e.g. post caps or brackets) for intermediate loads tended to equalize costs. However, helical pile foundation systems inclusive of beam attachments will negate the need for such hardware.

Ultimately, careful consideration of framing design will result in cost savings. Even so, these components represent a relatively minor project expense. Thus, structural enhancements that provide additional factors of safety and can accommodate desired or unforeseen future uses should be strongly considered.

Deck Framing with Face-Mounted Joists (Tenn, 2013)

Joist size and spacing is largely determined by span and applied loads. Specific layout and stiffness of decking material may also warrant additional supports to increase stability and reduce bounce. joist layout

36

Improper beam-post attachment (Tenn, 2013)

Anchoring beams to the face of posts results in shear stress that weakens hardware and wood. Beams should bear directly on posts either by notching the post or using appropriate mounting hardware.

bearing posts

The cantilever of beams and joists is an important consideration in framing design.

Beam cantilever can offer a cleaner appearance by setting foundations inward from the deck edge and can also accommodate small bump-outs for signage or to widen the deck without the need for additional supports. In a dropped beam configuration (joists atop beams), joist cantilever provides leeway in beam placement and can help accommodate turns. Depending on their direction, joist cantilever can also extend the deck.

Maximum cantilever for joists is equivalent to 1/4 of their total length and not more than 3 times their nominal depth.

Beams may cantilever 1/4 of their total length over each support. For example, a 4 foot beam span would allow 12 inch cantilevers, accommodating a 6 foot wide deck surface.

Joists with Dropped Beam (Abbinante, 2013)

Deck Cantilever (Decks.com, n.d.)

cantilever

Stresses Acting on Joints in Built-up Beams (Fine Home Building, 2001)

Beams indicated in the estimates on the next page can be created by “building-up” standard two inch nominal width boards to the appropriate size, thus adding strength and stiffness. To reduce stresses on the beams, individual members should bear atop support posts rather than “sandwiching” them. If joints/splices are necessary, they should occur over supporting posts and should be staggered in immediately adjacent members. built-up beams

37

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price per linearͲdeckͲfoot

$3

$4

$5

$6

$7

$8

$9

$10

$11

$12

$13

$14

$15

$16

$17

$18

$19

2x8

4'

8' span

2x10

6'

Deck Width 8'

2x12

2x8

2x12

2x8

12' span

2x10

2x12

2x10 14' span

2x12

While a ten foot span appears to optimize joist cost, a twelve foot span was chosen for determining beam size due to its impact on the cost of helical pile foundations. Requirements for span and joist spacing were derived from International Residential Code (IRC) and the American Wood Council. Only applied loads of 40psf (live) and 10psf (dead) were considered.

15-25%. However, untreated lumber is not recommended for exterior structural applications.

Material Nominal Dimensions and Joist Span

10' span

2x10

Joist layout and configuration has a direct impact on beam size. Here, all joists are flush mounted and utilize galvanized hangers and hanging nails.

When joists are flush mounted, beams should be of equal of greater width than joists. To increase rigidity over long spans, double blocking between joists is included for each deck segment. Due to its strength, economy, and availability, pressure treated southern yellow pine (PT SYP) lumber is the only material for which estimates are provided. Untreated Douglas fir lumber is often utilized in framing, and its use would reduce costs by approximately

framing estimates: joists

39

price per linearͲdeck Ͳfoot

$3

$4

$5

$6

$7

$8

$9

$10

$11

$12

$13

$14

$15

2x6 (2)

4'

8'

4x6 (1)

6'

Deck Width

2x6 (3)

2x8 (2)

2x8 (3)

2x10 (2)

Material and Nominal Dimensions and (number of members)

2x10 (3)

2x12 (2)

2x12 (3)

Galvanized

C150x12 (1)

Pricing includes galvanized medium duty post-to-beam brackets and nails.

Overall, hardware costs can be quite significant relative to the cost of lumber (especially for medium or heavy duty connectors). However, these associated costs may be reduced if helical pile foundation estimates are inclusive of necessary beam attachment hardware.

C-channel beam is also included. Built-up beams are noted by indicating the total number of members in parentheses following their nominal dimensions.

Pressure Treated Southern Yellow Pine

6x6 (1)

The main variables to consider with sizing a beam for a boardwalk are the deck width or beam span, the material used, and the span of the joists between beams. A longer joist span ultimately implies a greater deck load being applied to each beam. Due to the cost benefit of maximizing distance between foundations, only estimates associated with a joist span of twelve feet are provided. As with joists, spans were determined per IRC and American Wood Council requirements for PT SYP. Untreated Douglas fir was also priced but is not shown for reasons previously described. For reference, a galvanized steel

framing estimates: beams

Curbs & Guardrails Consideration of user safety is paramount to any project. Though guardrails and curbs are generally associated with protecting against falls, these features can also have a significant impact on overall user experience. By enhancing visual cues, they can provide a sense of security to pedestrians and subtly guide visitors to important areas or points of interest.

They can also provide opportunities for rest while enhancing other activities such as bird watching (e.g. by creating a place to steady a camera or binoculars).

Additionally, guardrails can act as a deterrent to entrance into sensitive environmental areas, and if built with care in mind, can certainly enhance the overall aesthetic of the boardwalk.

With respect to guardrails for decking, AASHTO and IBC codes differ in their application. IBC generally applies to commercial and some residential properties and would likely be referenced for any viewing platforms or large decks along the boardwalk. As the organization’s name implies, AASHTO guidelines were developed for transportation infrastructure and are applied to bridges and by the U.S. Forest Service to the development of a moderate risk, rural recreational trails. Ultimately, location, usage categorization, and

Trail Bridge Rail Systems (Groenier, 2007)

While building codes pertaining to residential and commercial decks and many forms of public transportation infrastructure are generally clear, their applicability toward components of recreational trail systems is not always as straightforward. In some instances, federal agencies such as the United States Forest Service (USFS) have synthesized recommendations from various sources in order to establish

guidelines that are based on anticipated usage and risk and attempt to make reasonable accommodations for the types of projects and challenges with which they are regularly faced. A similar approach has been taken here, by considering elements of the International Code Council’s International Residential Code (IRC) and International Building Code (IBC), as well as the American Association of State Highway and Transportation Officials (AASHTO) guidelines.

Elements from each were synthesized to define design details needed to derive cost estimates. Ultimately, the local regulatory body responsible for plan approval will make final determinations with regard to the applicability of codes for guardrails.

Building codes governing residential and commercial decks or pedestrian bridges are not necessarily applicable to components of recreational trails. The United States Forest Service (USFS) considers usage and risk in its guidelines for recreational trail guardrails: urban and high-risk areas (IBCbased), rural and moderate-risk areas (AASHTO-based), and remote and low-risk areas (OSHA–based). Municipalities may impose more or less stringent codes, but it is generally wise to follow industry best practices.

USFS trail bridge guardrails

40

accessibility will play significant roles in determining how guidelines should be applied.

At minimum, a short curb should be installed over the entire length of the boardwalk. This is a requirement for accessible trails or if the use of light maintenance vehicles is a consideration. The argument for designing and locating guardrails is more nuanced.

The IBC and IRC require that guardrails be installed wherever a walking surface is greater than 30 inches above grade. In moderate risk areas, the USFS recommends guardrails be installed where the walking surface is greater than 48 inches above grade. Despite the rural location of the Leopold Center, anticipated

usage of the boardwalk seems to indicate that the more stringent code be applied in this situation. Thus, care was taken to analyze marsh topography in order to balance guardrail requirements with economy and environmental risk factors (pgs. 48–51).

Beyond their location, considerations must be made for overall height and spacing between intermediate rails and the loading requirements for the guardrail. Both AASHTO and IBC maintain a 42 inch guardrail height requirement for pedestrian decks and bridges. Requirements increase to 54 inches if bicycle ...continued next page

Guardrail Design Notes • in many instances, recreational trails are not governed by specific code requirements; both current and future anticipated access and use should be considered when applying best practices; the U.S. Forest Service offers guidelines • IBC & IRC require guardrails when deck height exceeds 30 inches above grade • top rails must reach 42” above deck surface (IBC) • handrails are required along stairs and ramps (i.e. greater than 1:20 grade change) and along fully accessible routes

Post to Joist Connections Using Tension Brackets and Wood Blocking (Guertin, 2011)

• required spacing of intermediate rails varies: IBC (4 inch dia. sphere cannot pass through any portion); AASHTO, (6 inch dia. sphere cannot pass through any portion within first 27 inches; 8 inch dia. sphere between 27 and 42 in.)

• primary loading: must concurrently withstand a 200 lb. concentrated load from any direction applied at any point along top rail, and 50 lbs. per linear foot along the top rail • secondary loading: intermediate rails must withstand a horizontal normal load of 50 pounds per square foot

Guard Post to Outside Joist Example (AWC, 2013)

Making post to joist connections that meet loading specifications requires hardware and blocking that can adequately transfer the load to the framing. Screws or bolts alone are generally insufficient. For wood framing (e.g. posts attached to end joists) estimates, a detail derived from the American Wood Council and Simpson Strong-Tie Company, Inc. that combines through bolts, blocking, and Simpson DTT2Z brackets at each post was utilized. If changes to guardrail height, materials, hardware, etc. are made, professional design consultation is necessary to ensure that standards are still met. anchoring guardrail posts to framing

41

or equestrian traffic is desired. Spacing requirements for intermediate rails vary between 4 and 8 inches (see Design Notes, pg. 43) and may change above noted height thresholds.

must be designed to withstand a horizontally applied normal load of 50 pounds on an area equal to one square foot that includes openings and the space between rails.

Loading considerations for guardrails primarily impact connections between guardrail posts and framing. Given that vehicular traffic on the boardwalk is likely to remain minimal, IBC standards for loading were considered. Handrails and guardrails must be designed to resist a load of 50 pounds per linear foot, to resist a single concentrated load of 200 pounds applied in any direction and at any point along the top rail, and to transfer this load through the supports to the structure. Intermediate rails (all those except the handrail), balusters, and panel fillers

While final budget scenarios indicate applicable codes, IBC guidelines were primarily considered in estimates. All estimates include a top rail cap which helps to redistribute forces along rail posts and also acts as a rest for users. Though not considered ideal, a basic horizontal three rail system meeting minimum Forest Service and OSHA-based standards for remote/low risk recreational trails was also included in some of the budget scenarios. It is comprised of a top, bottom, and intermediate rail with maximum vertical openings of 15 inches.

From simple curbs to elaborate ornamental wrought iron panels or stainless steel posts, there are no shortage of materials available for achieving desired functional and aesthetic goals. Like decking, guardrails can represent either a modest investment or can easily inflate a project budget. However, there is arguably more room for creativity with guardrails.

simplicity, certain features such as the presence of a top rail cap, use of fascia mounting (as opposed to deck mounting), and a defined proportion of angles or turns (for angled brackets), were kept constant across all estimates.

The integration of features such as signage and seating into guardrails is also a possibility but is not described here.

Materials

Ultimately, a well designed and properly installed guardrail system can provide an elegant, finished look that adds enjoyment and comfort to user experience without distracting from the beauty of the surrounding environment.

Viewing Tower Guardrails at Blue Mound State Park, WI (Tenn, 2014)

Glen Kent Estates Boardwalk, Howard, WI (Janke General Contractors (n.d.)

A limited but diverse selection of materials was chosen for analysis. Where applicable, material notes described in previous sections should apply here (e.g. lumber types). For

Required spacing between railings varies based on anticipated use and risk. OSHA requirements (right) are less stringent than AASHTO requirements (left), as shown in the horizontal rails above.

However, additional intermediate rails can provide a cleaner, more balanced look. Many systems incorporating vertical intermediate rails (balusters) or panels will easily comply with more stringent IBC requirements (next page). guardrail spacing

42

Precast Concrete Curb on Boardwalk (PermaTrak, n.d.)

Curbs Where guardrails are unnecessary, adding curbs is an easy way to provide a sense of space, security, and direction for visitors by creating implied boundaries and enhancing sight lines. In all cases, curbs should be elevated approximately 2 inches above the deck surface to allow for drainage. Utilizing pressure treated lumber, basic curbs can be implemented at relatively little expense, but variety is possible when selecting size.

For instance, larger lumber (e.g. 4x4 versus 2x4) can help to better define the curb and will more readily resist weathering effects such as warping. Composites and alternative materials such as concrete (left) are also a possibility.

Town of Menasha Trail (Janke General Contractors, n.d.)

Horizontal Rails & Balusters/Pickets Beyond curbs, wooden horizontal guardrails provide the most basic accommodations.

As with decking, great variety can be achieved with materials and finishes. Size, spacing, and rail configuration can also have a great impact on aesthetics. A balustrade (series of balusters/pickets/spindles or other vertical elements) can be added for relatively little additional cost but can also be quite expensive if metal elements (e.g. wrought iron) are desired. Facades of composite or more expensive lumber can also add expense. Preservation of views for individuals who are unable to see above the top rail (e.g. small children, individuals in wheelchairs) is also an important consideration.

Cape Code Cable Railing (American Metal Specialties, n.d.)

Cable Railing Tension cable railings provide a clean finished aesthetic that can be incorporated into a variety of wood or metal structures. Their slim profile means that views of the surrounding environment remain relatively unimpeded, and views of the boardwalk itself may be less obtrusive. Costs are primarily driven by choice of post material (lumber or metal), wire (strength and corrosion resistance), type of hardware (a variety of tensioners are available), and the need for additional labor (e.g. drilling holes, swaging cables). Complex patterns and sharp/acute angles/curves also require additional posts and hardware (e.g. cable sleeves).

Iron Railing (Fortress Railing Products, 2013)

Wire Mesh Railing Along Boardwalk (Green, 2012)

Welded or Woven Wire Mesh & Infill Panels Metal panelling and wire mesh are efficient means of attaining code compliance while providing a clean, modern, and unobtrusive look that can be achieved at reduced expense relative to cable railings. Systems are generally comprised of plastic, metal wire (galvanized, stainless steel, or vinyl coated), or perforated metal sheets. Prefabricated panels are more expensive than rolls which can be difficult to unravel, cut to size, and install. If galvanized materials are used, galvanizing after weld is more expensive but is important to maintain corrosion resistance. Vinyl coated finishes offer a variety of colors and are made to be pliable and UV resistant.

Prefabricated/Manufactured and Metals Popular for use in residential decks, potentially low maintenance prefabricated railings of metal or plastics are offered by various manufacturers in different colors, styles, and textures, and are relatively simple to install. While versatile, aluminum or plastic panels may not provide a desirable look or feel for this particular project. Iron panels may provide a more suitable alternative but care is necessary in maintaining finishes/ coating in order to prevent rust.

43

44

price per linearͲdeckͲfoot

$0

$10

$20

$30

$40

$50

$60

$70

2x4 Curbs Only

2x6

Coated Wrought Iron

Custom Manufacturing®

Aluminum

Stainless Steel

Vinyl

Galvanized Steel

Cedar

Southern Yellow Pine

Material Type

4x4

Baluster/Picket

IBC compliant

Wire Mesh with lumber facing

Alternative Materials

Tension Cable

Prefabricated

Hardware estimates are based upon design details meeting IBC loading requirements. If applicable, manufacturer specified hardware (e.g. for prefabricated systems) is included. All hardware should be hot-dip galvanized or stainless steel. For image clarity, guardrail systems whose price fell well above the majority of other systems (e.g. tension cable systems with stainless steel or ipe lumber posts) are provided on the next page.

Guardrail Configuration

Horizontal Rail

OSHA compliant

In the chart below, guardrails are grouped by rail configuration and further differentiated by material. All costs assume that top rails terminate at 42 inches above the deck floor. Intermediate rail spacing is based on IBC requirements, except as indicated. All guardrail posts are presumed to be fascia mounted to end joists, with the exception of Custom Manufacturing’s railing kits which are mounted directly to extended foundation posts. A simple, unadorned top rail cap was included for all wood-frame railing systems.

guardrail cost estimates

45

price per linearͲdeckͲfoot

$0

$50

$100

$150

$200

$250

$300

$350

$400

$450

2x4

2x6 Curbs Only

Coated Wrought Iron

Custom Manufacturing®

Aluminum

Stainless Steel

Vinyl

Galvanized Steel

Ipe

Cedar

Southern Yellow Pine

Material Type

4x4

Horizontal Rail

OSHA compliant

Options for guardrails are nearly limitless. Unfortunately, expenses can share that quality. The graph below provides the same information as the previous page but includes wrought iron balusters and tension cable guardrail systems that give some indication of how extensive these costs can be. One utilizes stainless steel posts while the other utilizes ipe lumber for posts and trim.

guardrail cost estimates (continued)

Baluster/Picket

IBC compliant

Wire Mesh with lumber facing

Alternative Materials

Tension Cable

Prefabricated

Floodplain Considerations Flooding has long been a natural process in the Great Marsh and around Aldo Leopold’s Shack and Farm.

Development within the marsh is not without risk, and boardwalk design must take into account normal annual fluctuations in water level as well as periodic riverine flooding. Helical piles and framing can be engineered to anticipate forces associated with such events, but they are not the only components that can be designed with these environmental considerations in mind.

In order to prevent decay that might result from alternating wet and dry conditions, the structure’s framing should sit above this height. If joists are flush mounted and utilize boards between eight and twelve inches in width, the corresponding finished deck elevation would be approximately 807 feet. This elevation still places the deck below the surface of the 100year or 1% annual chance flood elevation within the marsh which varies between 808 and 809 feet above sea level (pg. 19).

Requirements for guardrails also increase as the deck is elevated. When utilizing the IBC standard requiring The boardwalk’s finished guardrails wherever the walkAldo Leopold and Flick Walking Down Flooded Levee Road deck height will impact ing surface exceeds 30 inches (courtesy Aldo Leopold Foundation Archives, 1936) framing and guardrail placeabove grade, the elevation ment and should be considerate of hydrologic conmodels on the following pages indicate that a large ditions within the marsh. In any given year, reguincrease in guardrail requirements along the boardlar water level can reach approximately 805 to 806 walk route occurs above an elevation of 807.5 feet. feet above sea level (NAVD88). This corresponds to approximately two to three feet above the ground.

While elevating the deck may reduce risk of uplift ...continued on page 50

46

area of detail

In order to quantify the need for guardrails along the length of the boardwalk, a 2 foot bare earth digital elevation model (DEM) of Sauk County (including the Great Marsh and surroundings) was analyzed using Esri’s ArcGIS 10.1. The model was used to create a topographic section (above) along the proposed boardwalk route. To enhance subtle topographic variation, the vertical scale was exaggerated by approximately 40-fold. Notable locations along the route were later added. Floodplain data for the Wisconsin River was also analyzed, and the 100-year floodplain or 1% annual chance flood elevation is included for reference. Increasing by nearly a foot as one proceeds in an upstream direction within the marsh (east to west), the flood elevation is provided as a range of 808 feet to 809 feet. A suggested finished deck elevation is shown at 807.5 feet. Based on this topographic information, proposed finished deck elevation, flood risk, and code requirements, guardrail placement can be determined for any point along the boardwalk route. topographic model

Proposed Boardwalk Route Elevation Profile (Tenn, 2014)

47

807.0’ 8 807 Impact of Deck Height on Railing Requirements Along Boardwalk Route (Tenn, 2014)

and/or pressure on the deck during times of high water, additional lateral supports may be needed to stabilize taller foundations within the unstable marsh soils. Appropriately designed anchors between foundations and framing will reduce the risk of dissociation from uplift.

Deck height should also be considered with regard to aesthetic and experiential functions.

In some instances, clearing the 100-year flood elevation would require raising the boardwalk’s deck upwards of 5 feet above grade. This would certainly alter the visitor experience within the marsh and would likely make the structure obtrusive from an outside perspective.

1195’

length boardwalk leng le ngth th ooff bo boar ardw dwal alkk with with deck height >30”

total % of deck height >30”

39%

increase in % total deck height >30”

n/a

deck less than 30” above grade (curbs only) deck 30” or greater above grade (guardrails required)

Provided with the necessary funding, nearly any deck height is attainable. However, the risk of damage due to flooding must be carefully weighed against the economic and experiential costs associated with averting that risk. An average deck elevation of 807.5 feet is recommended.

Coincidentally, this elevation corresponds to that of Levee Road at its intersection with the proposed boardwalk route.

48

boardwalk 500’ segment Building the entire boardwalk deck above the anticipated 100-year flood level (808–809 feet) may not be feasible. The cost of guardrails offers one deterrent. The maps here illustrate the proposed boardwalk route and indicate locations where finished deck elevation is at least 30 inches above grade for the given elevation above sea level.

807.5’ 807 deck height >30”

total

45%

1380’

increase

15%

808.0’ 80 deck height >30”

total

70%

2125’

increase

54%

808.5’ 80 deck height >30”

total

84%

2535’

increase

19%

809.0’ 80 deck height >30”

total

92%

2797’

increase

10%

Additional Features Beyond providing a safe means of passage from the Leopold Center to the Aldo Leopold Shack and Farm, the Great Marsh Boardwalk can offer numerous programmatic and functional values by moving visitors into close proximity with a rich and unique environment. While specific design elements have not yet been chosen, previous sections offer insights into how the boardwalk’s physical structure and layout might facilitate such experiences.

• Deck width is a key consideration for enhancing accessibility, allowing comfortable movement, and for the ability to allow concurrent mixed uses.

• Framing and foundation design will determine load bearing and the ability of the deck to host groups or to allow access for maintenance or emergency vehicles.

• The inclusion of a basic top rail cap transforms guardrails from a barrier into a welcomed resting post that can help keep a steady hand while snapping a photograph.

There are numerous other examples, and three additional items not yet noted are seating, interpretive and wayfinding signage, and multipurpose gathering spaces. Small viewing platforms provide opportunities for visitors to stop and enjoy their surroundings without fear that circulation will be interrupted. Given the overall length of the route and the variable physical abilities of users, these areas will also serve an important role as resting nodes. The fact that

Interpretive Sign at Logoly State Park (Arkansas Natural Heritage Commission, 2012)

there is very little shade or natural cover offered along the lengthy route also warrants the consideration of covered areas. Formal seating should be provided in these locations.

Such nodes would offer opportunities to define and highlight important historical, cultural, and environmental elements. Guardrail- or deck-mounted signs, as well as wayfinding (e.g. blazes, distance & location markers, etc.) along the trail, help to excite and reassure travelers as they follow the route. As previously noted in the discussion on framing (pg. 39), small deck outcroppings or bump-outs that make use of cantilevers could be used to accommodate signage or seating without the need for expensive additions.

Installation of stand-alone signage at some distance away from the boardwalk is also a consideration and may reduce the risk of vandalism.

Cost for small platforms was estimated by deriving a price per square foot directly from per linear-deckfoot estimates. This method accounts for all elements within the structure and for differences inherent to specific budget scenarios. It also allows for the addition of a specified number of nodes at various intervals along the proposed route. Signage allowances were based on materials previously acquired by the Aldo Leopold Foundation, and allowances made for bench seating were based on the design of the iconic Leopold Bench.

Interpretive Sign Mounted to Framing (City of Hinton, n.d.)

Interpretive and wayfinding signage may be mounted to the deck surface, directly to guardrails, directly to framing/joist connections, or it may sit apart from the boardwalk altogether. Regardless, careful planning is recommended in order to make necessary accommodations for deck width, mounting hardware, mounting height, legibility, etc. interpretive signage & wayfinding

50

Many visitors to the Leopold Center come or find themselves as part of a group setting while participating in an Aldo Leopold Foundation-offered class, presentation, or similar event (e.g. bird watching). The provision of a larger multi-purpose deck could accommodate such needs and would open the door to the development of new and exciting activities and offerings. A large open, elevated area along the second pond represents a possible location for a larger gathering space that could accommodate numerous programmatic elements.

multi-purpose deck

Preliminary Site Analysis for Multi-purpose Deck (Tenn, 2014)

Shelter at the ICF in Baraboo, WI (Tenn, 2014)

Within the marsh, there is very little natural cover, and a lean-to-inspired structure such as that at the International Crane Foundation (ICF) could provide shelter from sun and precipitation and provide a comfortable space for gathering, rest, and reflection.

basic shelters

Observation Tower in Marsh (Custom Manufacturing, Inc., 2014)

Observation towers can provide a unique vantage over the flat marsh landscape. Such a tower might also provide benefit during stewardship activities such as burning. However, the visual impact of such structures on the landscape may be undesirable. vantage points

51

Budget Scenarios (A1) Shallow Foundations: Volunteer-Led Installation Foundation: • 8ft. segment spans • pan footers in a combination of 50% large (19-1/2” sq) and 50% regular (15-1/2” sq) pans • span length may require installation of at least two additional bridges for which price is not included Deck: • 4ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x6) Framing: • PT SYP joists and beams • beams are doubled where prefabricated segments meet (the end of each segment constitutes a single beam member) • all costs included within “Decking & Framing” section below Railing: • horizontal “deck kits” along 45% of route • vertical railing kits are available • 2x4 curb kits along remainder Additional Features/Notes: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one every 500’ along route Foundation 15-1/2" x 15-1/2" 19-1/2" x 19-1/2"

quantity

unit cost

cost per deck ft

total cost

376 376

$58.00 $68.00

$14.54 $17.05

$21,808.00 $25,568.00

375

$220.00

$27.50

$82,500.00

207 169

$44.00 $200.00

$5.52 $25.04

$9,108.00 $33,800.00

units 3000

$0.00

$0.00

$0.00

$57.59

$172,784.00

Decking & Framing 4'x8' prefabricated panel

Railing/Curbs 2x4 curb kits horizontal rail kits

Installation cost per foot

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $1,382.27 $50.00 $1,000.00

cost per sqft $14.40 n/a n/a

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $9,383.88 $18,767.76

Total:

52

$8,293.63 $600.00 $6,000.00 $187,677.63

n/a n/a

$9,383.88 $18,767.76 $215,829.28

(A2) Shallow Foundations: Contractor Installed Foundation: • 8ft. segment spans • pan footers in a combination of 50% large (19-1/2” sq) and 50% regular (15-1/2” sq) pans • span length may require installation of at least two additional bridges for which price is not included Decks: • 6ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x6) Framing: • PT SYP joists and beams • beams are doubled where prefabricated segments meet (the end of each segment constitutes a single beam member) • all costs included within “Decking & Framing” section below Railing: • horizontal “deck kits” along 45% of route • vertical railing kits are available • 2x4 curb kits along remainder Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one every 500’ along route Foundation 15-1/2" x 15-1/2" 19-1/2" x 19-1/2"

quantity

unit cost

cost per deck ft

total cost

376 376

$58.00 $68.00

$14.54 $17.05

$21,808.00 $25,568.00

375

$265.00

$33.13

$99,375.00

207 169

$50.00 $200.00

$6.27 $25.04

$10,350.00 $33,800.00

3000

$60.00

$60.00

$180,000.00

$123.63

$370,901.00

cost per sqft $20.61 n/a n/a

$11,868.83 $600.00 $6,000.00

Decking & Framing 6'x8' prefabricated panel

Railing/Curbs 2x6 curb kits horizontal rail kits

Installation cost per foot

Total: View Decks/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $1,978.14 $50.00 $1,000.00

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $19,468.49 $38,936.98

Total:

$389,369.83

n/a n/a

$19,468.49 $38,936.98 $447,775.31

53

(B1) Helical Pile Foundation: Standard PT Boardwalk Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x8) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • three 2x6 horizontal rails (USFS low risk/OSHA compliant) w/ top rail cap along 45% of route • rail posts every 6ft. on-center • 2x6 curb along remaining 55% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, and curbs included Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one platform every 500ft. along route

54

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

502

$900.00

$150.60

$451,800.00

total cost

4500

$6.54

$9.81

$29,430.00

251

$56.32

$4.71

$14,136.32

1750

$16.46

$9.60

$28,809.78

552

$11.74

$3.93

$6,481.41

452

$39.04

$13.07

$17,647.55

3000

$60.00

$60.00

$180,000.00

$242.77

$728,305.06

cost per sqft $40.46 n/a n/a

$23,305.76 $600.00 $6,000.00

Decking 2x8 SYP

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 curbs PT SYP horizontal rails (top, bottom, middle) and rail cap

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $3,884.29 $50.00 $1,000.00

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $37,910.54 $75,821.08

Total:

$758,210.82 cost per sqft n/a n/a

$37,910.54 $75,821.08 $871,942.45

55

(B2) Standard PT w/ Vertical Guardrails Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x8) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • 2x6 and 2x4 horizontal rails and rail cap with intermediate 2x2 PT SYP balusters (IBC compliant) along 45% of route with rail posts every 6ft. on-center • 2x6 curb along remaining 55% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, curbs, and balusters Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one platform every 500ft. along route

56

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

502

$900.00

$150.60

$451,800.00

total cost

4500

$6.54

$9.81

$29,430.00

251

$56.32

$4.71

$14,136.32

1750

$16.46

$9.60

$28,809.78

552

$11.74

$3.93

$6,481.41

452

$50.13

$16.78

$22,657.00

3000

$60.00

$60.00

$180,000.00

$244.44

$733,314.51

cost per sqft $40.74 n/a n/a

$23,466.06 $600.00 $6,000.00

Decking 2x8 SYP

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 curbs PT SYP balusters (2x2), rails (top, bottom), rail cap, and posts

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $3,911.01 $50.00 $1,000.00

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $38,169.03 $76,338.06

Total:

$763,380.58 cost per sqft n/a n/a

$38,169.03 $76,338.06 $877,887.66

57

(B2a) Phased Approach: 500ft Segment to 1st Pond Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x8) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • 2x6 and 2x4 PT SYP horizontal rails and rail cap with intermediate 2x2 PT SYP balusters (IBC compliant) along 80% of route with PT SYP rail posts spaced every 6ft. on-center • 2x6 curb along remaining 20% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, curbs, and balusters Additional Features: • two 96 sqft. (8ft. x 12ft.) viewing platforms; one at each end of the boardwalk segment • single interpretive sign and two bench seats per platform

58

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

total cost

86

$900.00

$154.80

$77,400.00

756

$6.49

$9.81

$4,905.00

43

$54.79

$4.71

$2,356.05

294

$16.33

$9.60

$4,801.63

36

$10.91

$3.93

$392.81

136

$49.36

$16.78

$6,713.19

500

$60.00

$60.00

$30,000.00

$253.14

$126,568.68

Decking 2x8 SYP

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 curbs PT SYP balusters (2x2), rails (top, bottom), rail cap, and posts

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 2 4 2

unit cost $4,050.20 $50.00 $1,000.00

cost per sqft $42.19 n/a n/a

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $6,843.45 $13,686.91

Total:

$8,100.40 $200.00 $2,000.00 $136,869.08

cost per sqft n/a n/a

$6,843.45 $13,686.91 $157,399.44

59

(B3) Standard PT w/ Welded Wire Mesh Guardrails Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • pressure treated (PT) southern yellow pine (SYP) lumber deck boards (2x8) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • 3x3 galvanized after weld (GAW) welded wire mesh • 2x6 PT SYP top and bottom rails,top rail caps and 2x6 PT SYP top and bottom mesh facing/trim/border • IBC compliant railing along 45% of route with rail posts every 6ft. on-center • 2x6 curb along remaining 55% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, curbs, and facing Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one platform every 500ft. along route

60

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

502

$900.00

$150.60

$451,800.00

total cost

4500

$6.54

$9.81

$29,430.00

251

$56.32

$4.71

$14,136.32

1750

$16.46

$9.60

$28,809.78

552

$11.74

$3.93

$6,481.41

452

$81.22

$27.19

$36,713.22

3000

$60.00

$60.00

$180,000.00

$249.12

$747,370.73

cost per sqft $41.52 n/a n/a

$23,915.86 $600.00 $6,000.00

Decking 2x8 SYP

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 curbs 3x3 GAW welded wire mesh w/ PT SYP posts, rails (top, bottom), rail caps, and facing (top, bottom)

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $3,985.98 $50.00 $1,000.00

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $38,894.33 $77,788.66

Total:

$777,886.60 cost per sqft n/a n/a

$38,894.33 $77,788.66 $894,569.59

61

(C1) Helical Pile Foundation: White Oak & Tension Cable Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • quarter-sawn white oak deck boards (5/4x6) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • IBC compliant railing along 45% of route with PT SYP rail posts every 6ft. on-center • stainless steel cable rails (1x19 wire rope, 3/16in diameter) w/ turnbuckle tensioners • top and bottom 2x6 PT SYP rails and rail cap • 2x6 PT SYP curb along remaining 55% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, curbs, and facing Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one platform every 500ft. along route

62

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

502

$900.00

$150.60

$451,800.00

total cost

6000

$26.00

$52.01

$156,015.00

251

$56.32

$4.71

$14,136.32

1750

$16.46

$9.60

$28,809.78

552

$11.74

$3.93

$6,481.41

452

$135.45

$45.35

$61,221.21

3000

$60.00

$60.00

$180,000.00

$299.49

$898,463.72

cost per sqft $49.91 n/a n/a

$28,750.84 $600.00 $6,000.00

Decking 5/4x6 qtr sawn white oak

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 PT SYP curbs stainless steel cable (1x19, 3/16") w/ turnbuckle tensioners with PT SYP posts, rails (top and bottom), and rail cap

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $4,791.81 $50.00 $1,000.00

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $46,690.73 $93,381.46

Total:

$933,814.56 cost per sqft n/a n/a

$46,690.73 $93,381.46 $1,073,886.74

63

(C2) Helical Pile Foundation: Ipe & Tension Cable Foundation: • helical pile foundations • two piles every 12ft.

Deck: • 6ft. deck width • quarter-sawn white oak deck boards (5/4x6) • hardware: 3in. galvanized wood deck screws (two per joist) Framing (Joists): • 12ft. span • 2x8 PT SYP joists • 12in. max spacing/interval • double blocking between joists • hardware: Simpson LUC joist hanger and galvanized nails (as required by manufacturer) Framing (Beams): • 6ft. span • built-up beam: double 2x8 PT SYP • hardware: medium duty Simpson PC/EPC Post Caps and galvanized nails (as required by manufacturer) Railing: • IBC compliant railing along 45% of route with ipe rail posts every 6ft. on-center • stainless steel cable rails (1x19, 3/16in diameter) w/ field-swaged assemblies • top and bottom 2x6 ipe rails and rail cap • 2x6 PT SYP curb along remaining 55% of route • hardware: Simpson Strong-Tie deck tension tie DTT2Z and additional galvanized carriage bolts and screws for post attachment at edge/end joists • hardware: wood screws for guards, caps, curbs, and facing Additional Features: • six 96 sqft. (8ft. x 12ft.) viewing platforms • single interpretive sign and two bench seats per platform • approximately one platform every 500ft. along route

64

Foundation helical piling 12' spans

quantity

unit cost

cost per deck ft

502

$900.00

$150.60

$451,800.00

total cost

6000

$31.80

$63.60

$190,800.00

251

$56.32

$4.71

$14,136.32

1750

$16.46

$9.60

$28,809.78

552

$11.74

$3.93

$6,481.41

452

$563.46

$188.66

$254,684.99

3000

$60.00

$60.00

$180,000.00

$375.57

$1,126,712.50

Decking 5/4x6 Ipe boards

Framing (Beams) 2x8 PT SYP

Framing (Joists) 2x8 PT SYP

Railing/Curbs 2x6 PT SYP curbs stainless steel cable (1x19, 3/16") w/ field-swaged assemblies with Ipe posts and top rail

Installation

Total: Viewing Platforms/Nodes 8x12 platform platform seating outdoor signage allowance

quantity 6 12 6

unit cost $6,009.13 $50.00 $1,000.00

cost per sqft $62.60 n/a n/a

Total: Consultation Services design services (5% of cost) cost contingency (10% of cost)

quantity 1 1

unit cost $58,468.36 $116,936.73

Total:

$36,054.80 $600.00 $6,000.00 $1,169,367.30

cost per sqft n/a n/a

$58,468.36 $116,936.73 $1,344,772.39

65

Photo & Image Credits 01

Tenn, G. (photographer). (2014). Summer Wildflowers at the Leopold Center. (digital photograph)

09

Unknown (photographer). (ca. 1936) The Leopold Shack, Sauk County, Wisconsin, ca. 1936 (summer shot, framed by trees, woodpile in foreground) [b&w photograph]. retrieved from http://uwdc. library.wisc.edu/collections/AldoLeopold [hereafter cited LP, for Leopold Papers]. Series 3/1, Box 88, Folder 4.

Bradley, Charles C. (photographer). (1947). Aldo Leopold with binoculars [color photograph]. retrieved from LP. Series 3/1, Box 85, Folder 6.

10

Tenn, G. (designer). (2014). Wisconsin Counties and Waterways [map]. Modified from Wisconsin County Boundaries. [GIS shapefile]. 2004. Wisconsin Department of Natural Resources [hereafter cited as WI DNR]. retrieved from ftp://dnrftp01.wi.gov/geodata/ [hereafter cited as DNR FTP]; and Hydro 24k [file geodatabase]. 2014. WI DNR. retrieved from DNR FTP; and Light Gray Canvas Map. [basemap]. 2014. Esri. retrieved from http://www.esri.com/software/arcgis/arcgisonline/maps/ maps-and-map-layers Tenn, G. (designer). (2014). Sauk and Columbia Counties, Wisconsin [map]. Modified Google earth. [image landsat]. 2014. Google. 43°22’38,25”N and 89°40’10.37”W. 04/09/2013.

12

Tenn, G. (designer). (2014). “Great Marsh” Aerial [map]. Modified from DIGITAL ORTHOPHOTO (DOP) COVERAGE FOR SAUK COUNTY [digital ortho photography]. US Department of Agriculture. PRELIMINARY 2008 National Agriculture Imagery Program [hereafter cited as NAIP 2008]. retrieved from http://relief.ersc.wisc.edu/wisconsinview/form.php [hereafter cited as WiscView]; and Suak County Road Center Lines [GIS shape file] courtesy of Sauk County Land Information/GIS department [hereafter cited as Sauk LIGD].

14

United States Department of Agriculture (USDA). (photographer). (1937). Columbia9211937_141164_7x9 historic aerial photograph [aerial photograph]. retrieved from Wisconsin Historic Aerial Image Finder. http://maps.sco.wisc.edu/WHAIFinder/#

15

Tenn, G. (graphic designer). (2014). Partial ALF Property Boundaries [map]. aerial imagery (2008 NAIP) retrieved from WiscView; Suak County road center lines courtesy of Sauk LIGD.

16

Tenn, G. (graphic designer). (2014). “Great Marsh” Topography [map].

LiDAR and digital elevation model (DEM) information for Sauk and Columbia counties retrieved from WiscView; Suak County road center lines courtesy of Sauk LIGD.

17

Tenn, G. (graphic designer). (2014).“Great Marsh” Floodplain [map]. floodplain information retrieved from Wisconsin DNR Surface Water Data Viewer (hereafter cited as SWDV) and Federal Emergency Management Agency Map Service Center (MSC); LiDAR and digital elevation model (DEM) information for Sauk and Columbia counties retrieved from WiscView; Suak County road center lines courtesy of Sauk LIGD.

66

18

Tenn, G. (graphic designer). (2014). “Great Marsh” Soils [map].

Soil classification information retrieved from SWDV) and National Resource Conservation Service (NRCS) Web Soil Survey. http://websoilsurvey.nrcs.usda.gov/app/.

Road center lines courtesy of Sauk LIGD.

20

Tenn, G. (2014). (photographer). ATV Drill Rig in Marsh [digital photograph].

Tenn, G. (2014). (photographer). Marsh Soil Core [digital photograph].

21

Wisconsin DNR (2014). (author). Wisconsin statewide maps: Ecological Landscapes of Wisconsin [map]. retrieved from http://dnr.wi.gov/topic/landscapes/maps.html.

Wisconsin DNR (2014). (author). Wisconsin Statewide Maps: Soils Regions [map]. retrieved from http://dnr.wi.gov/topic/landscapes/maps.html.

22

Tenn, G. (graphic designer). (2014). “Great Marsh” Wetland Classification [map].

Wetland classification information retrieved from SWDV; Road center lines courtesy of Sauk LIGD.

23

Tenn, G. (2014). (photographer). Forested Wetlands around Marsh [digital photograph].

Tenn, G. (2014). (photographer). Emergent/Wet Meadows in Marsh [digital photograph].

Tenn, G. (2014). (photographer). Scrub Wetlands in Marsh [digital photograph].

Tenn, G. (2014). (photographer). Open Water Wetlands in Marsh [digital photograph].

WI DNR. (1992). (creator). Components of the Classification System [graphic]. retrieved from http://dnr.wi.gov/topic/wetlands/documents/WWI_Classification.pdf

24

Tenn, G. (graphic designer). (2014). “Great Marsh” Boardwalk Route [map].

DIGITAL ORTHOPHOTO (DOP) COVERAGE FOR SAUK COUNTY modified from NAIP 2008 retrieved from WiscView; Road center lines courtesy of Sauk LIGD.

25

Tenn, G. (2014). (designer). Aldo Leopold Memorial Site Plan [plan rendering].

Tenn, G. (2014). (photographer). Rain Garden Connecting Trail Segment [digital photograph].

Tenn, G. (2014). (photographer). Upland Trail Segment in Progress [digital photograph].

Tenn, G. (2014). (photographer). Second Pond Berm in Marsh (late spring) [digital photograph].

Tenn, G. (2014). (photographer). Levee Road Near Route Intersection [digital photograph].

26

Tenn, G. (designer & photographer). (2014). Boardwalk Conceptual Rendering [digital mixed media].

67

27

Helical Pile World. (2011). (photographer & installer). Jester’s Creek Path, Morrow, GA [digital photoraph]. retrieved from http://www.helicalpileworld.com/jesters-creek-helical-pile-boardwalk-project. html Tenn, G. (2014). (photographer). Horicon Marsh Boardwalk Deck [digital photograph].

American Metal Specialties. (n.d.). (photographer). Cable Railing Around a Pool (sherritt004)[digital photograph]. retrieved from http://www.cablerailings.com/cables-fittings-sherritt.html Ellis, Mark. (2014.). (photographer). “Solid Post Attachments With Threaded Rod.” Deck Magazine. threaded_rod_01_tcm122-2167304 [digital photograph]. retrieved from http://www.deckmagazine.com/fencing-and-railing/solid-post-attachments-with-threaded-rod_o.aspx Tenn, G. (2014). (photographer). Horicon Marsh Viewing Platform/Deck [digital photograph].

28

Custom Manufacturing®. (n.d.). (designer). Project Gallery: Custom Manufacturing bridge6 [digital photograph]. retrieved from http://www.custommfginc.com/images/portfolio/bridge6_lg.jpg Custom Manufacturing®. (n.d.). (designer). Project Gallery: Custom Manufacturing bridge3 [digital photograph]. retrieved from http://www.custommfginc.com/images/portfolio/bridge3_lg.jpg

29

Tenn, G. (2014). (photographer). Horicon Marsh Segment with Submerged Foundations [digital photograph].

Custom Manufacturing®. (n.d.). (designer). Typical Panel Layout [digital photograph]. retrieved from http://www.custommfginc.com/boardwalks.html

30

Alexander Mitchell & Son. (1848). (designer). Maplin Sand Lighthouse: Founded on Mitchell’s Screw Piles [architectural drawing]. retrieved from http://upload.wikimedia.org/wikipedia/commons/1/18/Maplin_Sands_Lighthouse_founded_on_Mitchells_screw_piles.jpg Hubbell Incorporated. (2013). (designer). Boardwalk and Walkway Foundation Bracket with Lateral Support System [architectural drawing]. retrieved from http://www.abchance.com/resources/ cad-drawings/

31

Danbro Distributors. (2013). (photographer & installer). Chance Solid Square Shaft Helical Pile [digital photograph]. retrieved from https://danbrodistributors.files.wordpress.com/2013/09/pile91613.jpg Reed Hilderbrand. (2011). (designer). Hand Driven Screw Piles [digital photograph]. retrieved from http://www.asla.org/2011awards/351.html

32

68

United States Department of Justice. (2010). American’s wiith Disabilities (ADA). Public Accommodations and Commercial Facilities (Title III). Figure A1. Minimum Passage Width for One Wheelchair and One Ambulatory Person. [drawing]. retrieved from http://www.ada.gov/reg3a/figA1. htm (image enhanced for legibility)

United States Department of Justice. (2010). American’s wiith Disabilities (ADA). Public Accommodations and Commercial Facilities (Title III). Figure A2. Space Needed for Smooth U-Turn in a Wheelchair. [drawing]. www.ada.gov/reg3a/figA2.htm (image enhanced for legibility)

33

Tenn, Greg. (2013). (photographer). Pressure Treated Pine Decking. [digital photograph].

Zverina, Robert. (2004). (photographer). Cedar Deck Complex Angles. [digital photograph]. http:// www.flickr.com/photos/shutterbuggery/6967853997/ Wolfe, Max. (n.d.). (photographer). George W. Bush Presidential Library Walkway. [digital photograph]. http://www.blacklocustlumber.com/george-w-bush-presidential-library.html Axion International. (n.d.). (photographer & installer). Project Portfolio: Timber Ridge Trail. [digital photograph]. retrieved from http://www.axionintl.com/composite-boardwalks.html Huffaker, Buddy. (2014). (photographer). Metal Grate Decking. [digital photograph].

36

Tenn, Greg.(2013). (photographer). Deck Framing with Face-Mounted Joists [digital photograph].

Tenn, Greg.(2013). (photographer). Improper beam-post attachment. [digital photograph].

37

Decks.com. (n.d.). Deck Cantilever. [drawing]. From Deck Cantilever Rules and Limits - How far can it span?. Decks.com by (no author listed). retrieved from http://www.decks.com/deckbuilding/ Deck_Cantilever_Rules_and_Limits__How_far_can_it_s Abbinante, Anna. (2013). Joists with Dropped Beam. [drawing]. From Cantilever Code Update.

Professional Deck Builder, 2013. November (p. 16–17). by Glenn Mathewson. retrieved from http:// www.deckmagazine.com/codes-and-standards/cantilevers-in-the-2015-code.aspx Fine Home Building.(2001). (publisher). Stresses Acting on Joints in Built-up Beams. [digital image]. From Joints in a built-up beam. Fine Homebuilding, 2001. 136 (p. 22). by David Grandpré P. E. retrieved from http://www.finehomebuilding.com/how-to/qa/joints-in-built-up-beams.aspx

40

Groenier, James.(2007). (engineer). Trail Bridge Rail Systems. [drawings]. From Trail Bridge Rail Systems. Technology and Development Pubications. 2007. 0723-2329P-MTDC. by James “Scott” Groenier.

United States Forest Service. retrieved from http://www.fs.fed.us/t-d/pubs/htmlpubs/htm07232329/ index.htm

41

Guertin, Mike. (2011). Post to Joist Connections Using Tension Brackets and Wood Blocking. [photograph]. From Code Compliant Guardrail Posts: Use hardware for fast, solid, cost-effective connections. Professional Deck Builder, 2011. May-June (p. 1–10). by Mike Guertin. retrieved from http:// www.deckmagazine.com/anchors/code-compliant-guardrail-posts.aspx American Wood Council (AWC). (2013). Fig. 25 Guard Post to Outside Joist Example. [architectural drawing]. From. Prescriptive Residential Wood Deck Construction Guide. Design for Code Acceptance, 2013. (p. 16). by AWC. retrieved from http://www.awc.org/Publications/DCA/DCA6/ DCA6-09.pdf

69

42

Janke General Contractors. (n.d.). Glen Kent Estates 2nd Addition Boardwalk Construction, Howard, WI. [photograph]. retrieved from http://jankegeneralcontractors.com/projects.asp?projectid=23 Tenn, Greg (2014). Viewing Tower Horizontal Railings at Blue Mound State Park. [photograph].

43

PermaTrak (n.d.). Precast concrete curb on boardwalk in urban park at Greenspace Zone Rec Center - Cleveland, OH. [photograph]. retrieved from http://www.permatrak.com/features-benefits/ railings/ Janke General Contractors (n.d.). Town of Menasha Trail. [photograph]. retrieved from http://jankegeneralcontractors.com/projects.asp?projectid=35 American Metal Specialties, Inc. (n.d.). Cape Code Cable Railing. [photograph]. retrieved from http://www.cablerailings.com/cables-fittings-capecod.html Green, Dale. (2012). J.N. Ding Darling Boardwalk. [photograph]. retrieved from http://blog. audubonguides.com/2012/10/02/photo-essay-ding-darling-national-wildlife-refuge/ Fortress Railing Products. (2013). Fe26 Iron Railing. [photograph]. retrieved from http://http://www. fortressrailing.com/gallery/fe26/

46

Unknown. (photographer). (1936). Aldo Leopold and Flick walking down flooded Levee Road [b&w photograph]. retrieved from LP Series 3/1b88, folder 4.

Tenn, Greg. (designer). (2014). Proposed Boardwalk Route Elevation Profile [mixed media].

LiDAR and digital elevation model (DEM) information for Sauk and Columbia counties retrieved from WiscView

48

Tenn, Greg. (designer). (2014). Impact of Deck Height on Railing Requirements Along Boardwalk Route [mixed media].

LiDAR and digital elevation model (DEM) information for Sauk and Columbia counties retrieved from WiscView; Suak County road center lines courtesy of Sauk LIGD.

50

Arkansas Natural Heritage Commission. (2012). (photographer). Interpretive Sign at Logoly State Park. [photograph]. retrieved from https://www.flickr.com/photos/naturalheritage/with/7583944104 City of Hinton. (n.d.). (photographer). Interpetive Signage along Beaver Boardwalk, Hinton, Alberta, Canada [photograph]. retrieved from http://www.hinton.ca/gallery.aspx?AID=15

51

Tenn, Greg. (2014). (photographer). Preliminary Site Analysis for Multi-purpose Deck. [drawing].

Tenn, G. (2014). (photographer). Trail Shelter at the International Crane Foundation in Baraboo, WI. [photograph].

Custom Manufacturing, Inc. (n.d.). (photographer). Observation Tower Built by Custom Manufacturing, Inc. [photograph]. retrieved from http://www.custommfginc.com/project-gallery.html

70

71

Selected Resources Leopold References:

01

Laubach, Stephen A. (2014). Living a Land Ethic: A History of Cooperative Conservation on the Leopold Memorial Reserve. Madison, WI: University of Wisconsin Press

02

Meine, Curt. (2010). Aldo Leopold: His Life and Work (2nd ed.). Madison, WI: University of Wisconsin Press. Board of Regents of the University of Wisconsin System.

03

University of Wisconsin Digital Collections Center: The Aldo Leopold Archives. (2011). Board of Regents of the University of Wisconsin System. Retrieved from http://digital.library.wisc. edu/1711.dl/AldoLeopold

Construction/Design References:

04

American Association of State Highway and Transportation Officials (AASHTO). (1997). Guide Specifications for Pedestrian Bridges.

05

American Forest & Paper Association: American Wood Council. (2012). Design for Code Acceptance. Prescriptive Residential Wood Deck Construction Guide. Retrieved from http://www.awc.org/ publications/DCA/DCA6/DCA6-12.pdf

06

American Metal Specialties, Inc. (n.d.). Cable Railing Technical Specifications. Retrieved from http:// www.cablerailings.com/technical-cable-information.html

07

American National Standards Institute (ANSI) and National Association of Architectural Metal Manufacturers. (2009) Metal Bar Grating Manual (7th ed.). Retrieved from http://www. ohiogratings.com/pdfs/NAAMM_manual_531.pdf

08

Amico Grating. (2014). Bar Grating Product Specification Guide. Retrieved from http://www.amicograting.com/bargrating-specifications.htm

09

California Redwood Association. (Oct. 1998). Redwood Lumber Grades and Uses. Retrieved from http://www.calredwood.org/pdf/Grades+Uses.pdf

10

Chance Civil Construction. (2013). Helical Piles & Anchors. Retrieved from http://www.abchance. com/products/helical-piles-anchors/.

11

C I Banker Wire and Iron Works, Inc. (2011). Exterior Railings and Stairways. http://www.bankerwire.com/architectural-wire-mesh/portfolio.php?application=Exterior%20Railings%20and%20 Stairways&appid=1

12

Deardroff, Donald A, PE. (Apr. 2009). Design, Installation, and Testing of Helical Piles and Anchors.

Retrieved from http://www.foundationperformance.org/pastpresentations/DeardorffPresSlides8Apr09.pdf

13

Groenier, James. (2007). Technology and Development Pubications: 0723-2329P-MTDC. Trail Bridge Rail Systems. Washington, D.C.: United States Forest Service. Retrieved from http:// www.fs.fed.us/t-d/pubs/htmlpubs/htm07232329/index.htm

72

14

Hesselbarth, Woody, Brian Vachowski, and Mary Ann Davies. (2007). Trail Construction and Maintenance Notebook. Washington, D.C.: United States Forest Service Technology and Development Program. Retrieved from http://www.fhwa.dot.gov/environment/recreational_trails/ publications/fs_publications/07232806/toc.cfm

15

Hubbel Power Systems, Inc. (2014). Helical Piles. Retrieved from http://www.hubbellpowersystems. com/anchoring/foundation/helical-piles/default.asp

16

International Code Council. (2012). Section 1013 Guards. Chapter 10 Means of Egress. International Building Code. Retrieved from http://publicecodes.cyberregs.com/icod/ibc/2012/index.htm.

17

International Code Council. (2012). Section R311. Means of Egress. Chapter 3 Building Planning.

International Residential Code. Retrieved from http://publicecodes.cyberregs.com/icod/irc/2012/ icod_irc_2012_3_sec011.htm?bu2=undefined

18

Loferski, Joseph, Frank Woeste, PE, Dustin Albright, and Ricky Caudill. (Feb. 2005). Strong RailPost Connections for Wooden Decks. The Journal of Light Construction. Retrieved from http:// www.jlconline.com/lumber/strong-rail-post-connections-for-wooden-decks_2.aspx#

19

Lorallen Fabrication Services. (2013). Custom Railing Infill Panels. Retrieved from http://lorallen. com/

20

Lutenegger, Alan J, PE, PhD. (2011). Technical Bibliography on Design, Construction and Performance of Screw-Piles and Helical Anchors. Retrieved from http://www.helicaldrilling.com/Documents/ISHFBibliography_1.pdf

21

Mathewson, Glen. (2012). Top 10 Deck-Building Mistakes. Fine Home Building. The Taunton Press, Inc. Retrieved from http://www.finehomebuilding.com/how-to/articles/top-10-deck-buildingmistakes.aspx#ixzz3JXuBFkmk

22

McNichols Company. (2010). Quality Wire Mesh - Square Mesh Products. Retrieved from http:// www.mcnichols.com/products/wire-mesh/square-mesh

23

NAHB Research Center. (2003). Hybrid Wood and Steel Details– Builder’s Guide. Washington, D.C.: United States Department of Housing and Urban Development. Retrieved from http:// www.huduser.org/portal/publications/Hybrid_Steelguide.pdf

24

Simpson Strong-Tie Company Inc. (Nov. 2008). Barrier Membranes & Preservative-Treated Wood. Technical Bulletin T-PTBARRIER08-R. Retrieved from http://www.Strong-Tie.com/ftp/ bulletins/T-PTBARRIER08-R.pdf

25

Simpson Strong-Tie Company Inc. (Mar. 2010). Code Compliant Guardrail Post Connections.

Technical Bulletin T-GRDRLPST10. Retrieved from http://www.Strong-Tie.com/ftp/bulletins/TGRDRLPST10.pdf

26

Simpson Strong-Tie Company Inc. (Jul. 2008). Preservative-Treated Wood. Technical Bulletin T-PTWOOD08-R. Retrieved from http://www.Strong-Tie.com/ftp/bulletins/T-PTWOOD08-R. pdf-PTWOOD08-R

73

27

Southern Forest Products Association. (2014). New Design Values. Retrieved from http://www. southernpine.com/new-design-values/

28

Souther Pine Inspection Bureau. (2014). Lumber Grading Rules. http://www.spib.org/wood-services/lumber-grading-rules?/lumberservices

29

Western Wood Products Association. (2002). Douglas Fir & Western Larch Species Facts. Retrieved from http://www2.wwpa.org/SPECIESPRODUCTS/DouglasFir/tabid/405/Default.aspx

30

Wisconsin Department of Transportation (DOT). (2011). Designing Pedestrian Facilities. Wisconsin Guide to Pedestrian Best Practices. Retrieved from http://www.dot.wisconsin.gov/projects/state/ ped-guide.htm

31

Wisconsin Department of Transportation (DOT). (2014). Transportation Alternatives Program.

Bicycle and Pedestrian Facilities Program. Retrieved from http://www.dot.wisconsin.gov/localgov/ aid/bike-ped-facilities.htm

General References:

32

Mossman, Michael J, Yoyi Steele, and Steve Swenson. (Mar. 2009). A Strategic Vision for Bird Conservation on the Leopold-Pine Island Important Bird Area

33

Ice Age Trail Alliance. (2014). Ice Age Trail Glossary. Retrieved from http://www.iceagetrail.org/iceage-trail/ice-age-trail-glossary/

34

Ice Age Trail Alliance. (2014). Ice Age Trail Landscape & Geology. Retrieved from http://www. iceagetrail.org/ice-age-trail/ice-age-trail-landscape-geology/

35

Lange, Kenneth I. (2014). Song of Place: A Natural History of the Baraboo Hills. Baraboo, WI: Ballindalloch Press.

36

Lewis M Cowardin, Virginia Carter, Francis C Golet, and Edward T LaRoe. (1979). Classification of Wetlands and Deepwater Habitats of the United States. Washington, D.C: Fish and wildlife service. Office of Biological Services. Retrieved from http://www.fws.gov/wetlands/Documents/ classwet/index.html. .

37

United States Army Corps of Engineers (USACE). (n.d.). St Paul District. Retrieved from http:// www.mvp.usace.army.mil/Missions/Regulatory.aspx

38

United States Department of the Interior: Fish and Wildlife Service (FWS). (2014). Wetland Classification Codes. Retrieved from http://www.fws.gov/wetlands/data/wetland-codes.html

39

Wisconsin Department of Natural Resources (WI DNR). (Feb. 1992). Publication WZ-WZ023: Wisconsin Wetland Inventory Classification Guide Publication. http://dnr.wi.gov/topic/wetlands/documents/wwi_classification.pdf

40

WI DNR. (various dates). Ecological Landscapes of Wisconsin Handbook. Retrieved 2014 from http:// dnr.wi.gov/topic/landscapes/Handbook.html

74

41

WI DNR. (n.d.). Waterway Protection: Wetland Disturbance. Retrieved from http://dnr.wi.gov/topic/ Waterways/construction/wetlands.html

42

WI DNR. (n.d.). Instructions for Informational Requirements for Practicable Alternatives Analysis for Recreational Trail Projects. Retrieved from http://dnr.wi.gov/topic/Waterways/documents/PAA/ PAAsuppRecTrails.pdf

43

WI DNR. (2014). Wetland Compensatory Mitigation. Retrieved from http://dnr.wi.gov/topic/wetlands/mitigation/

44

WI DNR. (2013). Wetland General Permit for Recreational Development. Retrieved from http://dnr. wi.gov/topic/waterways/documents/permitDocs/GPs/GP4.pdf

Geospatial Information & Data

45

ArcGIS for Desktop. (version 10.1) [software]. (2011). Redlands, CA: Environmental Systems Research Institute (esri). Retrieved from http://www.esri.com/software/arcgis/arcgis-for-desktop/

46

Federal E Emergency Management Association (FEMA). (2013). Flood Insurance Rate Map (FIRM) Sauk County Wisconsin and Incorporated Areas: Map Numbers 55111C0267F, 55111C0267F, 55111C0258E, and 55111C0259E. Flood Map Service Center. Retrieved from http://msc.fema.gov/portal

47

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