TRAIL ASSESSMENT MANUAL
Refugio Nacional de Vida Silvestre Caletas-Arío Nicoya Peninsula, Costa Rica
Prepared for CIRENAS Dave Weber & Kate O'Brien The Conway School — Spring 2015
Index
Acknowledgements We would like to thank the many people who generously shared their time, expertise, and even their homes, cars, and meals with us during this project. In particular, we would like to thank our primary contacts in Costa Rica, Karla Cosgriff and Sam Kenworthy of CIRENAS, who hosted us during our time there. Karla and Sam provided us with local knowledge, orientation, and help establishing the goals for this document. We would also like to thank the members of the Grew family who took time to talk with us about the history of Hacienda ArĂo, CIRENAS, and the Refugio. The Costa Rican employees of the ranch, including the cowboys and the housekeeping staff at CIRENAS made our stay more comfortable and provided local perspective that might otherwise have eluded us. During our short visit to Monteverde we had the pleasure of touring the cloud forest reserve with Fransisco Munoz Lopez, who not only offered us expert interpretation of the flora and fauna, but also offered valuable insight on the pros and cons of different types of trail construction. Both prior to our visit to Costa Rica and afterwards, we were privileged to spend time with Peter Jensen learning the art and science of trail building. His advice on how to go about gathering data prior to our departure, as well as the wonderful day-long workshop he lead at the Conway School, were tremendously helpful given the short time frame of this project. Finally, we would like to thank the faculty and staff at school who have tirelessly edited our work, shared their years of knowledge and experience, all the while, motivating us despite their own exhaustion. They are a truly dedicated bunch worthy of great admiration.
Client & Project Scope ................................................................1 Site History................................................................................. 2 Visitors and Access..................................................................... 3 Climate & Watershed.................................................................4 Broad Analyses I......................................................................... 5 Broad Analyses II........................................................................6 Uplands: Slopes & Drainage...................................................... 7 Uplands: Views, Vegetation & Shade........................................8 Uplands: Summary Analysis.......................................................9 Glossary of Trail Terminology I................................................ 10 Glossary of Trail Terminology II................................................ 11 Glossary of Trail Terminology III...............................................12 Trail Assessment Flowchart......................................................13 Trail Planning Overview............................................................14 Sustainability.............................................................................15 Trail System Concept I.............................................................. 16 Trail System Concept II.............................................................17 Trail System Concept III........................................................... 18 Trail System Concept IV........................................................... 19 Trail System Concept V............................................................ 20 Observation Platforms..............................................................21 Signs.......................................................................................... 22 Bridges, Boardwalks, Stairs..................................................... 23 Grade Reversals........................................................................ 24 Full Bench Cut........................................................................... 25 Maintenance............................................................................. 26 Data Collection I....................................................................... 27 Data Collection II...................................................................... 28 Data Collection III..................................................................... 29 Resources.................................................................................30 Photo Credits.............................................................................31
CIRENAS is a non-profit organization with a mission to connect people to the environment through education, research, and innovation. The organization offers short term and summer programs for international high school students and other groups. CIRENAS’ campus, located within the 1,900-hectacre Hacienda Arío ranch on the southwest coast of Costa Rica’s Nicoya Peninsula, offers program participants an opportunity to immerse themselves in a lifestyle that demands an increased awareness of their impact on the environment and which encourages them to investigate and take part in regenerative land management practices. In order to increase its capacity for this work, the organization has begun construction of a new, larger campus which will serve as a functioning model of regenerative agriculture, efficient rainwater management, and food system innovation. There CIRENAS will be able to offer longer-term, universitylevel programs and research opportunities as well as an improved venue for engagement with the local community. This new campus is located adjacent to the Refugio Nacional de Vida Silvestre Caletas-Arío (Caletas-Arío National Wildlife Refuge), which CIRENAS manages jointly with the government and another non-profit. CIRENAS sees tremendous educational value in the Refugio and seeks to integrate it further into its own programs and draw more attention to it as an appealing regional destination. To that end, CIRENAS has identified the following goals for this document: 1. Assess the existing Refugio trail system’s suitability for increased use. 2. Recommend design improvements to increase durability, minimize environmental impact, and reduce necessary maintenance. 3. Identify ways to improve trail users’ physical and educational experience. 4. Develop a conceptual design for a trail connection between CIRENAS’ new campus, the Refugio trail system, and the Refugio ranger station.
Nicoya Peninsula Hacienda Arío
Estuary Río Bongo
Río Arío
The project focus area consists of a peninsula at the Refugio’s southeast end covering roughly 95 hectares. It is bordered by the Pacific Ocean to the west, an access road and CIRENAS’ new campus to the south, active cattle ranch to the east, and the Río Arío, Río Bongo, and Río Bongo Estuary to the north. This portion of the Refugio currently features a ranger station in its southeast corner and approximately 3 kilometers of trails. These include a short trail leaving the ranger station and returning to the road just south of it and a longer trail which stretches the length of the Refugio, exiting onto the beach at the focus area’s northwest tip. This trail features two spurs, the westernmost of which terminates at the estimated highest point in the focus area.
Long Trail Active Ranch (Hacienda Arío)
Highest Point
Legend Central Hill
Project Focus Area Campus Center
Low
er
Ranger Station
Upper
Existing Trail
Southeast Hill
High Point Grassland
New CIRENAS Campus
Tropical Dry Forest Wet Meadow Charral (Scrub) Mangrove Dune Grass Beach
Short Trail
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ad
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June 30, 2015
Marine Protection Zone
Client & Project Scope
Project Focus Area
Trail System Assessment
New CIRENAS Campus Location
Not for construction. Part of a student project and not based on a legal survey.
• Established in 2003 from public lands and an adjoining parcel of cattle pasture donated by Hacienda Arío. • Includes 7.5 kilometers of beach, 333 hectares of land, the Río Bongo estuary, and a marine protection zone extending 22 kilometers from shore. • Protects vital nesting grounds of four species of sea turtle, habitat for more than 200 species of native and migratory bird as well as a variety of other fauna, and a rich mangrove ecosystem. • One of the only protected areas in Costa Rica under joint public and private management.
Area Enlarged Below
Prepared By: Kate O’Brien & Dave Weber
CIRENAS
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Wildlife Refuge
Due to limited time on-site for the design team, lack of physical access to much of the Refugio, and a lack of topographic and ecological data, this document outlines a process for trail assessment rather than proposing site-specific design solutions. Further data collection and site analysis is needed prior to any future development of the conceptual designs presented in this document.
Refugio Quick Facts
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Client & Project Scope
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Mangroves extending much of the way down the Refugio’s west side as well as part of the way down the estuary side have been protected under Costa Rican law since 1996. These forests offer excellent wildlife habitat and help stabilize the shoreline and riverbanks during storms and flood events.
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Wider Vegetated Buffers
Estuary Río Bongo
Areas of former cattle pasture have been re-vegetating since 2000 and became formally protected along with the rest of the Refugio in 2006. In many places, particularly the uplands, dense thickets of thorny scrub, locally referred to as “charral,” have filled in where grass once grew. Occasional very large trees, which previously provided shade for cattle, dot the landscape. These include impressive specimens of guanacaste, cenízaro, and ceiba among others. The majority of the other trees are much younger. These patterns of residual and successional vegetation could be incorporated into the visitor experience highlighting regrowth.
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2005
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Active Ranch (Hacienda Arío)
Trail System Assessment
5 Legend Project Focus Area
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Campus Center Ranger Station Existing Trail High Point Grassland
New CIRENAS Campus
Tropical Dry Forest Wet Meadow
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Charral (Scrub) Mangrove Dune Grass Beach
2011
2013
June 30, 2015
The confluence of the Río Bongo and Río Arío has changed significantly over time and will continue to do so indefinitely. The historical aerial photos below show the formation of the Río Bongo oxbow as well as changes in the size and course of the rivers’ channels. Views of this dynamic landscape offer visitors to the Refugio excellent opportunities to learn about the erosive and depositional power of water to reshape the landscape over time.
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Prepared By: Kate O’Brien & Dave Weber
First cleared during the post-World War Two population boom, much of the land surrounding the Refugio remains open and in active use for grazing or crop cultivation. In recent years, Hacienda Arío has taken steps to establish wider vegetated buffers along the streams and rivers running through its pastures. This may help diminish erosion and nutrient runoff into the estuary and adjacent marine protection zone.
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Río Arío
Site History
new campus site is also a former cattle pasture, but has only 4 CIRENAS’ been out of active grazing for less than a year. Its uneven topography and vegetation offer a glimpse of what the southeast portion of the Refugio may have looked like in the early 2000s.
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Not for construction. Part of a student project and not based on a legal survey.
The current trail system was cleared in 2008. Much of it follows old cattle paths or tractor access roads, many of which go directly up and down steep slopes and along ridge tops. This makes for uncomfortable walking and may be exacerbating erosion.
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Site History: Transforming Ranch land into a Refuge
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Visitors & Access: Trail System Seeks Additional Users Who is likely to visit the Refugio?
Quebrada Nando
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Rainy Season Route
5 km
10 km
On Foot Students and researchers from CIRENAS’ new campus will walk across the road to reach the Refugio trail system. Section of Beach Frequently Driven On
Manzanillo
Cóbano
Santa Teresa Public access between the Refugio and Manzanillo via Hacienda Arío’s roads (large orange arrow) could decrease traffic along the beach and enable visitors to reach the Refugio regardless of tides.
CIRENAS students visit the Refugio to study its various ecosystems and to learn about watershed dynamics.
The Refugio offers a valuable educational venue for local school children on field trips.
The huge variety of bird species evident in the Refugio make it an excellent destination for tourists interested in birdwatching.
Not for construction. Part of a student project and not based on a legal survey.
A defined footpath linking the CIRENAS campus to the Refugio trail system could help prevent the creation of informal trails. On Horseback or Bicycle Hacienda Arío offers equestrian and mountain bike tours of the ranch that frequently pass by the Refugio and new CIRENAS campus along the road. Tours combining horseback riding or mountain biking on the ranch with educational visits to CIRENAS’ campus, and guided or unguided hikes through the Refugio could offer excellent opportunities to highlight the different land management strategies used in each area without requiring visitors to use a motorized vehicle for transportation. By Car, ATV, or Motorcycle There are currently two ways for members of the public to reach CIRENAS’ new campus and the Refugio ranger station and trailhead in a vehicle. Those coming from points to the southeast such as the regional transportation hub of Cóbano or the surfing mecca of Santa Teresa can drive as far as Manzanillo on roads, but must travel the last few kilometers along the beach. Those coming from the north can use the access road leading to the beach, but this route involves two river fords, which, along with sections of the road itself, often become impassable during the rainy season. The alternative, rainy season route, which crosses the rivers via the closest bridges, is nearly seven times longer and would once again require visitors to drive north from Manzanillo along the beach. Add to this the questionable status of the road between the beach and Refugio during rainy season and it seems very unlikely that the Refugio will receive many visitors during the rainiest months of September and October. Considering the Refugio’s role in the protection of sea turtle nesting habitat and CIRENAS’ mission to promote regenerative rather than destructive relationships between people and their environment, the ongoing use of the beach between the Refugio and Manzanillo as a road should be strongly discouraged. With that in mind, CIRENAS might consider providing visitors alternative access to its campus and the Refugio via Hacienda Arío’s private network of ranch roads.
June 30, 2015
1 km
Prepared By: Kate O’Brien & Dave Weber
How will they get there?
Trail System Assessment
Dry Season Route
Visitors & Access
There are four likely visitor profiles: • Students and/or researchers from CIRENAS • Members of local communities involved in CIRENAS programs • Foreign tourists, especially those on ranch horse/bike tours and those interested in birdwatching • Costa Rican tourists during holidays Diverse visitor demographics may make it especially important for navigational and interpretive materials such as maps and signs within the Refugio to be multilingual and approachable for visitors with varying levels of education and familiarity with the site. Trails of different lengths and difficulties will better accommodate the greatest range of visitors
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The Southern Nicoya Peninsula receives between 80 and 120 inches of rainfall annually. The heaviest rains fall from May through October, peaking in September (see annual rain chart). The dry season is from November through April during which there is almost no precipitation. The abrupt shift from extreme wet to extreme dry may exacerbate flooding, erosion and subsequent sedimentation of river and marine areas. These can result in nutrient loading of waterways, which may disrupt their fragile ecosystems. The year-round average daytime high is 90 degrees Fahrenheit. Locals work from 5 am to 2 pm as the sun is oppressive in the afternoon. The daytime heat and humidity may affect when visitors come to the Refugio. The combined watersheds of the Río Bongo and Río Ario, total roughly 425 square kilometers. Steep mountainous terrain dominates the northern twothirds, which is mostly forested. The southern third is flatter and mostly cleared for pasture land. During heavy rains, the Ario and Bongo may rise dramatically.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Climate & Watershed: Weather Shifts Contribute to Dynamic Landscape
Trail System Assessment
This watershed funnels water toward the Refugio, where the terrain is flatter. As a result, more than 50 percent of the project focus area may be impacted by rainy season flooding (see map at right). Floodplain trails are likely to be damaged during this period, making maintenance intensive. Necessary trail maintenance could be minimized by rerouting or discontinuing trails in areas likely to be impacted by high water. Given the lack of further information on the extent of rainy season flooding, the design team has opted to focus more closely on those trails in the Refugio’s uplands that are not subject to flooding.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Seasonal flooding has caused catastrophic damage to the lower segment of the short trail. This is likely to worsen with future flood events. Closure of this trail segment may help minimize future maintenance.
x
Annual Rainfall Per Month Watershed of the Rios Arío and Bongo
June 30, 2015
Prepared By: Kate O’Brien & Dave Weber
Refugio Focus Area
The dry season, which correlates with the northern winter brings tourism to the Nicoya Peninsula. April marks the end of the dry season and beginning of wet season during. During this shift, a huge variety of native and migratory birds gather in and around the Refugio. This could be a major attraction for tourists interested in birdwatching. CIRENAS currently hosts school programs predominately during vacations including spring and summer breaks. Although this is the rainy season, the rain often occurs in the afternoon. Tourism decreases and stores take a break during September and October when it rains throughout the day. Rain may impact visitation and whether trails should be kept open year-round.
Climate & Watershed
Watershed
Not for construction. Part of a student project and not based on a legal survey.
Estimated Annual Flooding of the Refugio
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Rio Bongo
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Rio Ario
Ranger Station Campus Center Existing Sign Sign Needed Unexplored Area Lack of Signs
Coastal Restrictions and Mangroves
Pacific Ocean
Estuary
Due to its location between the Pacific Ocean and the Rio Ario, Rio Bongo, and Rio Bongo Estuary, portions of the Refugio are subject to restrictions. On the Pacific side, there is a coastal restriction on construction extending 200 meters inland from the median water level. The first 50m of this is patromonio nacional, or property of the nation. This area may not be altered by any private citizen. The next 150m can be privately owned, but is subject to restrictions on building and timber harvesting. On the river/estuary side, there is a 25m buffer within which cutting of timber is prohibited. Finally, in 1996, Costa Rica outlawed the cutting of mangroves, thereby acknowledging the unique importance of these trees and the habitat they create. Efforts should be made to relocate trail segments that currently pass through the Refugio’s mangroves. The construction of structures such as observation platforms may require permitting if they are located within the coastal buffer.
Rio Bongo
Legend Ranger Station Campus Center Mangrove Legal Restrictions
Pacific Ocean
Not for construction. Part of a student project and not based on a legal survey.
Rio Ario
Prepared By: Kate O’Brien & Dave Weber
Trail System Assessment
Legend
Broad Analyses I
Dense vegetation prevented exploration through the most of the Refugio during the design team’s field work in April 2015. The area in magenta represents the portion of the Refugio that was not explored by the design team. Time spent walking the existing trails provided the team with a basic understanding of site topography and vegetation. Ground-truthing and further analysis will be required in order to lay out and construct a new, sustainable trail that provides access to the rest of the Refugio. The Refugio lacks signs to help visitors orient themselves, navigate the trails, or interpret the landscape, and flora and fauna. The only sign that mentions the Wildlife Refuge is located at the ranger station, elevated above the road and only legible to traffic driving toward the beach. There are two existing signs along the beach; however, they are hidden within the dunes. These signs prohibit people from stealing turtle eggs but do not identify the area as a National Wildlife Refuge. The black circles with plus signs mark those places where signs are most needed to help navigation, identify the Wildlife Refuge, and with interpretation. The addition of navigational and interpretive signs to the Refugio would immediately improve the user experience. Signs should be placed at the trailheads and at each intersection with information about the trail’s length, difficulty, and attractions.
Estuary
June 30, 2015
Limited Data, Existing and Missing Signs
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Broad Analyses
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1
Estuary
Areas of opportunity (purple circle) and constraints (red x) are the control points that help to determine the layout of a trail. The trail should be rerouted to avoid areas of constraint including severe erosion and ditches, and should provide access to areas of opportunity such as viewpoints, significant vegetation, trees that could potentially support platforms, and areas for gathering. 1 The trail in the northwest corner serves as a good example. It should be moved inland away from the edge of the estuary and the ecologically important mangroves. Susceptibility to flooding, frequent damage due to crab excavations, and proximity to crocodile habitat and are all constraints to that section of trail. The two areas of opportunity within this portion of the trail provide significant views of the estuary and might be accessed via trail spurs with less impact.
Rio Bongo
Legend Ranger Station Campus Center Constraint Opportunity
Summary Analysis
Estuary
Rio Ario
Legend Ranger Station Campus Center Constraint Opportunity Lack of Signs Mangrove Legal Restrictions Unexplored Area Sign Needed Existing Sign
Pacific Ocean
Broad analyses II
Rio Bongo
Not for construction. Part of a student project and not based on a legal survey.
Any area that has been identified as a constraint and is within the coastal restriction should be abandoned as it is impacting sensitive habitat. There is potential for spurs to allow limited access to areas of opportunities, such as viewpoints that are within areas of constraint. Directional and educational signs with information about the trail and pictures of features should be located at or prior to viewpoints. These signs can encourage visitors to trail destinations and increase users’ education about surrounding landscape. Signs should be located where the trail transitions topography, vegetation or habitat to increase users’ understanding of the overall landscape. On the outskirts of the Refugio, signs and trailhead kiosks could be added to educate visitors about the National Wildlife Refuge and welcome them into the trail system. Additional signs along the trails could help interpret the various habitats, vegetation and larger views users will encounter. Positive control points and areas of constraint or restriction can be used to propose trail direction and form.
Pacific Ocean
Prepared By: Kate O’Brien & Dave Weber
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Rio Ario
June 30, 2015
Control Points
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Broad Analyses
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4 3
Steep Slope: Sheet drainage flows from the upper trail, 1 eroding the steep slope here and eventually eroding the lower trail. This portion of the trail, located on the ridge top, is compacted by human use and lacks vegetation, which reduces soil permeability and increases sheet drainage down the face of the slope. Intersection: Channelized drainage flows down the trail from 2 two directions and converges at the three-way intersection. Steep slopes along the trail increase the speed of runoff and subsequent erosion. At the intersection, water flows perpendicular to and continues down the trail. Eroded Ditch: Water flowing from the east and west converges 3 at the three-way intersection and flows down the path to the north. This has resulted in catastrophic erosion of the trail in the from of a large washout.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Three-Way Intersection
Trail System Assessment
1 Short Loop
Legend Ranger Station Campus Center Sheet Flow Steep Slope
Steep, erosion-prone slopes along and adjacent to the Refugio’s trails could be stabilized with vegetation. Plants with deep roots help to secure soils and absorb run-off, reducing erosion. Vetiver (left) is a native grass that is being used for this purpose at the new CIRENAS campus. It has very deep roots which grow to an average of 2 meters.
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Steep slope
3 2
Intersection
4 3
Eroded ditch
Not for construction. Part of a student project and not based on a legal survey.
Channelized Flow
Prepared By: Kate O’Brien & Dave Weber
3 2
Uplands: Slopes & Drainage
The existing trail system is affected by steep slopes in several areas, especially between the upper and lower sections of the short loop trail and along the section of the trail closest to the river. Severe erosion, including small landslides and undercutting, is evident in these areas. Channelized drainage flows down the trail in places, particularly at the three-way intersection where the long spur diverges. Foot traffic, very steep slopes, and water converge, resulting in significant erosion.
June 30, 2015
Water Takes The Short, Steep Way Down
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Uplands: Slopes & Drainage
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Uplands: Views, Vegetation & Shade Pockets of Shade Make for Comfortable Observation
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Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
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Legend Ranger Station Campus Center Notable Tree Fallen Tree View
Large trees including guanacaste, cenízaro, ceiba are scattered along the Refugio trail. These trees are not only awe-inspiring on their own, but also provide expansive shade and could potentially support observation platforms. A platform would enable vistas of the landscape, and reduces the compaction of soil around the tree’s roots which restricts their ability to uptake water and oxygen. Site review and expert analysis would be required before a final decision is made about platform locations.
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Deep shade under a massive guanacaste
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Steep slope washout
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Viewpoint overlooking the river bend
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A potential gathering space in the shade of palm trees
Not for construction. Part of a student project and not based on a legal survey.
Shade
Uplands: Views, Vegetation & Shade
Trail System Assessment
1
June 30, 2015
4
Prepared By: Kate O’Brien & Dave Weber
Dense vegetation creates naturally shaded, cool microclimates in several places along the trail; however, these patches are less common along ridges and on hilltops where intense sun can make hiking uncomfortable. Several majestic trees scattered along the trail form shady nodes and could be featured as gathering spaces for resting or group activities. It may be possible to construct platforms in these trees to provide views from higher elevations for further information see amenities section. Deep Shade: Palm trees growing amidst a stand of guanacaste trees 1 offer deep shade. There is potential to use one of the large guanacaste trees to support a platform for viewing the southwest. Washout: Several trees have fallen on the steep slopes between the 2 upper and lower short trail segments. This has exposed an area of unstable soils which shows signs of washouts. River View: The existing viewpoint is located on a steep slope which 3 appears to be eroding and is not stable. An expansive view of the river can be obtained slightly to the south in an area that is more stable, and shaded. Shade and View: The short spur leads to a large area shaded by palm 4 trees. This area features a partial view to the east and may be comfortable for gathering.
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Uplands: Summary Analysis Reroute trails to improve durability
Lower Short Trail: The lower segment of the short trail is negatively 1 affected by flooding in the rainy season and has steep, unstable slopes to the west, which result in heavy, erosive runoff. This portion of the trail should be abandoned and re-vegetated. Intersection: The three-way intersection suffers from severe erosion as 2 the trails leading into it from the east and west are located on the fall line and channelize runoff. Central Hill: The hilltop at the end of the long spur offers the best 3 potential for views of the entire Refugio, but lacks shade. A raised structure here could provide shade and capitalize on this viewshed. Upper Short Trail: The upper segment of the short loop offers potential 4 views with shade but follows the ridge top, which has a steep, unstable slope to the east. This trail could be rerouted to the sideslope west of the ridge to better manage drainage. Access to the viewpoint might be maintained via a spur.
Three-Way Intersection
Central Hill
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
1
Trail System Assessment
4 Upper Short Loop
Legend Ranger Station Campus Center
The following section outlines trail terminology and includes illustrations that convey the spatial relationships between terms. An understanding of this vocabulary will greatly aid those seeking to assess and/or plan trails.
Channelized Flow Steep Slope Notable Tree
X
Fallen Tree Shade
Trails that follow the ridge line exacerbate erosion both down and off the trail because the trail is compacted by human disturbance, which reduces permeability. The sustainable solution would be to move the trail off the ridge and to re-vegetate the abandoned trail. New vegetation will stabilize the soils and infiltrate run-off. For example, the pochote tree can stabilize soils and its spikes deter visitors, which allows the path to re-vegetate.
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Lower short trail
2
Intersection
3
Central Hill
4
Upper short trail
Not for construction. Part of a student project and not based on a legal survey.
View
Uplands: Summary Analysis
Sheet Flow
June 30, 2015
3
2
Prepared By: Kate O’Brien & Dave Weber
The trail traverses steep slopes along the Refugio’s two hills. Each of these hills offers significant views, majestic trees and refuge from the sun. The eastern face of the southern hill is extremely steep, which has resulted in significant visible erosion and fallen trees. Based upon site analysis, modifying the trail would improve user’s experience and reduce site impact. There are three primary conclusions of this analysis: portions of the trail should be abandoned and re-vegetated, modified in place, or realigned.
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Glossary of Trail Terminology I This glossary is meant to familiarize users of this manual with trail and trail building terminology. Wherever possible, terms are depicted along with other relevant terms to better demonstrate their relationships. Terms that are not illustrated appear in gray boxes.
esl
ope
pe
lo
ks
ac
B
Floodplain: An area of low-lying ground adjacent to a river formed mainly of river sediments and subject to flooding. Riparian Zone: The area of influence of a river including all associated soils, flora and fauna
Trail Tread
Level
Outslope
Linear
Finish Spur
Trail Alignment Start
Loop Horseshoe
Positive Control Point
Control Points: The starting point, ending point, and fixed points in between that broadly dictate the alignment of a trail through the landscape. These may include limitations (negative) such as cliffs or wetlands as well as appealing destinations (positive) such as an outlook, notable landscape feature such as a specimen tree, or a swimming hole. Trail Alignment: The course a trail takes through the landscape. Common alignment types include linear, spur, horseshoe, loop, and stacked loops.
Backslope: 1. The uphill face of any excavation. 2. The slope (%) of the cut bank on the uphill side of a bench cut trail. Critical Edge: The lower or outer edge of the trail tread which is rounded to allow for drainage to continue downhill. Outslope: The difference in elevation across a trail’s tread from its inner, uphill edge to its outer, downhill edge that assists in the shedding of water across and off of the tread. Typically 5-8%. Sideslope: The natural slope of the landscape perpendicular to a trail’s tread or corridor. Trail Corridor: The area of passage of the trail, including all cleared and managed parts above, below, and adjacent to the tread. Trail Tread: The travel surface of a trail.
Established walkway
ng
ni
Fa
ll L
n Ru
Sid
es
lop
e
ine
e
op
Sl
Maximum Sustainable Grade: The maximum running slope for an ascending trail segment. This depends on soils, precipitation patterns, vegetation, and the type of use expected. In general terms, inclined natural surface trails should have slopes in the 2-10% range. Grades above 10% will likely require some improvement or hardening of the tread in order to maintain it in place, especially in areas receiving very heavy precipitation. Above 20%, steps and/or hardened surfaces are necessary.
Social/Desire Path
Social/Desire Path: An informal trail formed by users seeking the shortest route to a destination. These trails often disregard environmental concerns.
Fall Line: The most direct route, perpendicular to the topographical contours, down a slope. The path water will follow as it flows downhill. Running Slope: A trail segment’s slope along its length. One-Third Rule: The running slope of a trail segment should never be greater than one-third of the sideslope it traverses. This prevents the trail from becoming a fall line trail, ensuring that runoff maintains momentum flowing across the trail instead of running down it.
Not for construction. Part of a student project and not based on a legal survey.
Stacked Loops
Negative Control Point
Critical Edge
June 30, 2015
Sid
Prepared By: Kate O’Brien & Dave Weber
Floodplain
Glossary of Trail Terminology I
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Trail Corridor
Riparian Zone
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Glossary of Trail Terminology II Slope Failure
Ang l Rep e of ose
Rolling Contour Trail
Displacement
Soil Texture: The particle size(s) present in a given soil. Firm and Stable Tread: Tread that resists compression or horizontal distortion under use. This is most often achieved though the creation of a well-graded tread material featuring a mixture of clay, silt, sand, and angular stone particles that can be well-compacted and which binds together. Steps, paving, and boardwalks may be used in places where this is impossible. Poorly Graded/Highly Uniform Soils: Soils composed of a single particle size. These soils tend to have a low capacity for compaction and are undesirable for trail tread construction
Full Bench Cut (section view)
Half Bench Cut (section view) Cut
Sideslope Tread
Tread
4-6 meters
<20% Slope Crown Geotextile
Climbing Turn: A reversal in the direction of the trail as it ascends a slope in which it briefly climbs directly up the fall line. This type of turn has several advantages over a switchback, especially the limited excavation it requires. However, this type of turn should only be constructed where the terrain’s natural slope does not exceed 15-20%. The wider radius (4-6m) of a climbing turn as compared to a switchback also makes it less likely that users will shortcut the corner. Grade reversals should be created immediately before and after the curve of a climbing turn and its tread should be outsloped to prevent water from flowing down the fall line portion of the trail.
Fill Retaining Structure
Full Bench Cut: An excavation into a hillside that creates a relatively level shelf, or bench, wide enough to accommodate a trail’s full tread width. For further information on this technique see the Details section. Half Bench Cut: Similar to a full bench cut except that the excavation is only deep enough to create a shelf half the width of the planned trail tread. The excavated material is then relocated to the downhill edge of that shelf where it is compacted and retained with a short wall, thus creating the outer half of the tread’s width. Turnpike
Climbing Turn
Trail System Assessment
Well Graded
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Soil Texture
Rolling Contour Trail: A highly erosion-resistant trail that traverses along sideslopes more or less on contour and which incorporates an outsloped tread and frequent grade reversals. Whenever possible, these reversals are formed in response to natural features. This adds to the feeling that a trail is part of the landscape it passes through, not a gash across it. Where the trail climbs or descends, it crosses contours at oblique angles (see Maximum Sustainable Grade and One-Third Rule) to ensure that water continues to sheet across the trail naturally instead of channeling down it. Grade Reversal: A drainage feature on sections of inclined trail consisting of a brief change in the trail’s running slope from uphill to downhill for a distance of approximately 3 meters followed by a gradual return to the original slope. This effectively divides the watershed of a hillside into smaller sections and prevents runoff from flowing down the trail for long distances. Depending on the intensity of rainfall and steepness of the sideslope in a given area, it is generally recommended that grade reversals be every 5 to 15m.
Wet Ground
Crown: The domed cross-section of a trail’s tread that facilitates positive drainage of water off the trail. Typically used on trails in flat areas. Turnpike: A raised trail tread retained with stones or logs that is crowned to shed rain into ditches along its sides. Commonly used in flat, wet areas.
Glossary of Trail Terminology II
Poorly Graded
Natural Obstacle
Not for construction. Part of a student project and not based on a legal survey.
Firm and Stable Tread
Grade Reversal
Prepared By: Kate O’Brien & Dave Weber
Angle Of Repose: The maximum incline on which a material, such as soil, can maintain itself in place. Slope Failure: The collapse of a bank or hillside; often associated with intense rain events, poor excavation, clear-cutting, and inadequate regrading or stabilization of backslopes. Erosion: The wearing away or removal of surface material by water, wind, ice, friction, or gravitational forces. Displacement: The sideways movement of soils caused by inevitable kicking, grinding, and acceleration of feet, hooves and wheels.
June 30, 2015
Erosion
North
11/21
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Glossary of Trail Terminology III O A Drainage
C
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Drainage: The removal of water or groundwater by means of surface or subsurface movement.
Duff
Channelized Drainage
Duff: The loose organic material found on the surface of the ground, often extending into the first organic horizon.
Seepage
Root Zone
Root zone: The part of the soil horizon that is penetrated by roots.
Soil Permeability
Runoff: Surface discharge by overland flow and/or channel flow. Sheet drainage: water flowing across the surface of the ground and not in. Channelized drainage: water moving in a channel.
Seepage: The gradual movement of ground or interflow water from the soil to the surface along an extensive area, generally a hillside; gradual movement of water through the soil.
Compacted
Permeability: The soil’s capacity to absorb and transfer water; the rate at which rock or soil infiltrates water.
Not for construction. Part of a student project and not based on a legal survey.
Highly Permeable
Prepared By: Kate O’Brien & Dave Weber
Trail System Assessment
Sheet Drainage
Runoff
Glossary of Trail Terminology III
Soil Profile: A vertical excavation that shows the different soil horizons.
June 30, 2015
B Soil Profile
North
12/21
Yes Call an engineer. Consider a raised walkway.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
No
Yes
No
Yes You’re Good!
Is there flowing water? Ridge top?
Flat?
No
No No In a wetland or floodplain?
Is it eroding?
Across sideslope? Is the
Yes
Yes
Yes
Is it eroding?
Assess the tread composition and trail use.
Or
trail...
Regrade to reestablish outslope. No
Assess the tread composition and trail use.
No Realign trail to sideslope.
Yes
No Yes
Ascending or descending?
Yes
You’re Good! Across sideslope?
Yes
Outslope of at least 5-8%?
Is it eroding?
No
Yes
Does the running slope exceed 1/3 of the natural sideslope?
Yes
Regrade and consider grade reversals.
No Are there grade reversals? Realign the trail to achieve 1/3 ratio or, if that is impossible, consider stairs.
Realign or regrade to create grade reversals and outslope.
Trail Assessment Flowchart
No
Not for construction. Part of a student project and not based on a legal survey.
Outslope of at least 5-8%?
Prepared By: Kate O’Brien & Dave Weber
Consider a raised walkway for seasonal crossing.
Realign off ridge top?
Trail System Assessment
Yes
June 30, 2015
Prior to analysing the location and composition of an existing trail, the following questions must be asked: Is the trail worth maintaining? Is it the only way to get to a destination? Does it impact sensitive environments or pass through dangerous areas? Consider closing a trail if it does not serve a purpose or is negatively impacting an area. Otherwise, use this chart to assess an existing trail. Colored icons refer to other sections in this report with further information about future steps to be taken. The orange icons refer to construction recommendations or a need for further assessment, which are described in more detail later. The red icons represent recommendations that require further site analysis prior to design of a new trail. The following page outlines the process of planning a new trail from start to finish.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail Assessment Flowchart
North
13/21
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail Planning: Starting with a Clean Slate The following framework, which is derived from leading trail construction and maintenance manuals, outlines the full start-to-finish process of planning, designing, and constructing a new sustainable trail.
5. Confirm Design and Complete Trail Layout
6. Build the Trail
Determine the trail’s purpose.
Gather and interpret data on site and context levels.
Create a report that summarizes the previous steps.
Develop preliminary trail design on basemap.
Assess the proposed trail design in the field.
Construct the trail.
Walk the focus area to check and modify the positive and negative control points identified during analysis phase.
Slopes
Describe the physical and social context.
•
Conservation
Drainage
•
Recreation
Consolidate analyses into a basemap.
Viewpoints Identify potential user groups. Vegetation Identify immediate stakeholders. Natural Shade Research available funding to establish a tentative budget.
Navigation Soil •
Test stability
•
Angle of repose
Climate Important Natural Communities
Establish initial design standards which include, but are not limited to, trail height and width, appropriate slopes for intended users and distance between resting points. Determine general trail location and relationship to existing trails Analyze cost benefits. Identify patrol and maintenance personnel and maintenance budget. Identify initial opportunities and constraints (derived from site analysis).
Access and Circulation Identify the legal status of the land and any restrictions. Compile a list of necessary permits and permissions. Describe the physical and social context. Identify stakeholders, partners, and potential supporters and strategize their involvement. Identify potential access points, parking, and any associated issues.
Establish a general form of trail such as a loop, horseshoe, or out-and-back that meets the established criteria. Define materials and the built form of the trail based on design standards. Give consideration to various user experiences. Follow rolling contour trail principles to maximize trail durability and limit negative environmental impact.
Walk the proposed trail alignment created during the design step and redefine initial opportunities and constraints.
After the prior planning, designing and layout steps are complete, the next and final step is constructing the trail.
•
Do not strictly limit yourself to the proposed route. Be sure to explore alternative routes in the vicinity to determine whether there is a better alternative.
Information about tools, details and construction can be found in the trail guides cited in the Resources section.
•
Verify running slopes of proposed trail alignment to ensure their sustainability
Note patterns of the topography, vegetation, and drainage along the designed trail to check for discrepancies. Identify any additional positive control points the proposed route that might enhance it further.
Not for construction. Part of a student project and not based on a legal survey.
Define area management objectives. For example:
June 30, 2015
4. Develop Preliminary Design on Basemap
Trail System Assessment
3. Summarize Analyses
Prepared By: Kate O’Brien & Dave Weber
2. Analyze the Site
Trail Planning Overview
1. Establish Trail Objectives
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Due to limited data availability, time on-site, and physical access to much of the Refugio, the design team was only able to complete portions of steps 1,2, and 3. Going forward, these steps should be revisited and completed thoroughly before steps 4, 5, and 6 are begun. For a more detailed version of this framework, please refer to the USDA’s Trail Construction and Maintenance Notebook and Larry Lechner’s Trail Planning, Construction and Maintenance in Parks and Protected Areas.
North
14/21
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
What Makes A Trail System Sustainable? Designing For A Complete, Long-Lasting Trail
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Trail Durability
A Sustainable and Enjoyable Refugio Trail System
Physical Experience
Educational Experience
Fulfilling Educational Experience
Two fundamental components make up the educational experience offered by a trail: access and interpretation. First and foremost, an educational trail must be laid out so as to give its users access to the notable attributes of the area. Depending on the area’s management objectives, this access may include the ability of users to see, hear, smell, touch or even taste their surroundings. The more ways users can experience their surroundings while using a trail, the more rich an experience they are likely to have. Once the desired level of access is established through trail alignment, there are many ways to provide users interpretation of their surroundings, be it through an expert guide, an audio tour, a guidebook or pamphlet, or well-placed, substantive signs. All of these techniques have their benefits and a combination of them may make for the richest experience; however, well-designed signs on their own provide an excellent interpretive foundation that can be enjoyed by users regardless of the availability of a guide, functioning audio equipment, or copies of books or pamphlets at the time of their visit. The conceptual design on the following sheets is meant to illustrate how these three attributes might be incorporated into a re-imagined, more sustainable trail system for the Refugio.
Not for construction. Part of a student project and not based on a legal survey.
The exertion required to travel along a trail and the emotional responses it elicits contributes to the user’s physical experience. Users are more likely to have a positive experience when they are able to match their ability level and desired experience to an appropriate trail. The existing trail system in the Refugio does not offer users many choices of length or difficulty. The following elements offer multiple comfortable options for a range of trail users: • Firm and stable tread composition: Well-compacted tread will be less permeable and shed runoff better. • Stacked loops: Multiple trail loops offer users many different lengths, difficulties, and destinations. • Curvilinear alignment: The up-and-down of grade reversals as well as side-to-side curves in the trail give it a pleasing rhythm and flow. • Comfortable microclimates: Depending on the climate, sun or shade may provide additional comfort. • Destinations and attractions: Views, observation of flora and fauna, notable geological formations, swimming holes etc. draw visitors in. Rest stops with seating provide incremental destinations for users with different ability levels. These may be sited to coincide with the above-listed attractions. The following design principles help create a rewarding emotional experience: • Orientation and navigation: Signs inform users of the length, difficulty, and attractions of different trails and help them find their way with peace of mind. • Mystery: Trail is aligned to limit users’ view down the trail, dividing the experience into short segments. • Surprise and Awe: Attractions such as impressive views are revealed suddenly, so as to enhance their emotional impact. • Privacy: Whenever possible, parallel trail segments are kept far enough away from one another to minimize noise and visual interference between different user groups.
Sustainability
Positive Physical Experience
Prepared By: Kate O’Brien & Dave Weber
A trail’s durability boils down to its ability to withstand erosion, which can be caused by water, use, or wind. Of these, water and, to a far lesser degree, use are the greatest concerns at the Refugio. The primary objective of trail design or redesign should be to limit the trail’s exposure to water. Specifically, it is important to prevent water from running down a trail or collecting on it. There are several design/building techniques that help prevent erosion: • Firm and stable tread composition: Tread should be well compacted, free of organic material, and incorporate a mix of different particle sizes. • Rolling contour trail layout incorporates the following: ¤¤ trail alignment traversing the sideslope of hills ¤¤ sustainable running slopes (depending on soil stability and sideslope) ¤¤ frequent grade reversals (every 5 to 15 meters) ¤¤ sufficient tread outslope (5 to 8%) • Use of natural landscape features such as natural benches, large boulders, bedrock outcrops, and large trees as anchors gives a trail a more natural looking and potentially less intrusive trail alignment. A trail that successfully sheds water to avoid erosion will require less maintenance, have less negative environmental impact in the form of sedimentation, and provide the base for a positive user experience. It will also help prevent users from making their own paths to avoid mud, washouts, and other damage.
Trail System Assessment
Durability
June 30, 2015
A trail system’s durability as well as the positive physical and educational experience of its users are important factors projecting a trail’s sustainability. The relative weight of each of these depends on the management objective of the area within which the trail is to be built and the objective and target users of the trail itself. Identification of these baseline objectives will help determine if a trail is appropriate and what type and intensity of use it should be designed to support. It is possible to design a sustainable trail that combines durability and a good physical user experience without consideration for the user’s educational experience (such as a bike path or running trail), just as it is possible to design an interpretive trail that is too narrow or winding for running or biking. Wherever possible, the Refugio trail system should incorporate all three of these attributes, as well as the Refugio’s conservation management objectives.
North
15/21
Río Bongo
4
Río Arío
Legend Project Focus Area Campus Center Visitor Center
Trail System Assessment
*This design is strictly conceptual and is only meant to illustrate broad design principles. Any future trail construction must be preceded by further data collection, planning, and careful layout.
Estuary
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Site analysis for the majority of the Refugio was severely limited by time and availability of topographic and ecological data. This conceptual trail system redesign seeks to build on the identified positive and negative control points and estimated environmental constraints to demonstrate how an improved network, incorporating better durability and a positive, engaging physical and interpretive experience for users, might look like. In this re-imagining, much of the existing trail system is abandoned in favor of alternative routes that should be less prone to erosion and which may offer a richer user experience. This, in turn should decrease the trail system’s negative environmental impact, thereby better respecting the Refugio’s conservation objectives. Over the pages that follow, this concept is discussed further through the lenses of durability, physical user experience, and educational user experience.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail System Concept: A Robust Network for Exploration and Discovery
3
Trailhead Kiosk Restrooms Parking Point of Interest
1
Major Attraction Existing Trail
2
Beach Trail Altered In Place Realigned Trail Grassland Tropical Dry Forest Wet Meadow Charral (Scrub)
Some Highlights The addition of another beach access point due west of the visitor center provides an alternative to walking down the road for groups from CIRENAS and other visitors. This is not only a more pleasant walk, passing through four different vegetation zones, but it also brings users to the beach farther from the section that is commonly driven on. This new trailhead also decreases the length of time that visitors must walk along the unshaded beach if they choose to hike the outermost loop.
2
The most notable points of interest identified during site visits are included in the redesign, stretching the length of the Refugio. These include incredible specimen trees, views, and shaded gathering spaces. Three primary destinations — excellent outlooks above the Río Arío, atop the central hill, and on the dune overlooking the beach and estuary—anchor the trail system, rewarding users on hikes of varying length.
3
In an effort to minimize the network’s negative environmental impact and enhance its durability at the same time, existing trail segments immediately along the estuary’s edge, as well as those along the steep slope in the floodplain at the bend in the Río Arío, are abandoned and re-vegetated. New trails, further inland from these areas of chronic flooding and erosion, connect to valuable points of interest via spurs. This limits both the amount of trail that is exposed to destructive forces and that of fragile environments, such as mangroves, that are exposed to human foot traffic.
4
Not for construction. Part of a student project and not based on a legal survey.
The revised network offers users many options. Several loops of different lengths and difficulties combine to make the new trail system more flexible to provide users with different interests and abilities a variety of experiences to match. These loops allow visitors greater access to different areas within the Refugio and provide a more novel experience than a linear, out-and-back trail.
1
June 30, 2015
Beach
Prepared By: Kate O’Brien & Dave Weber
Dune Grass
Trail System concept I
Mangrove
North
16/21
Río Bongo
1 Río Arío
Lowlands
2
Trail System Assessment
*This design is strictly conceptual and is only meant to illustrate broad design principles. Any future trail construction must be preceded by further data collection, planning, and careful layout.
Estuary
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Erosion is the single greatest threat to a trail’s sustainability. If allowed, it will render a trail less enjoyable or even dangerous and may cause significant damage to the surrounding environment by adding sediment and accompanying nutrient load to waterways and the area offshore of the estuary’s mouth. Several principles and design elements combine to increase the conceptual system’s durability and decrease its potential negative impact on the surrounding ecosystem: • Firm and Stable Tread: The entire conceptual trail system benefits from improvements to the trail tread itself. In the uplands, this is accomplished by adding crushed stone to the dirt tread and thoroughly compacting it. In the lowlands a crowned tread (turnpike) or a system of boardwalks could be built, depending on seasonal flood level. (Further site analysis is necessary to determine appropriate building techniques.) • Minimize Trails Along Waterways: The trail along the estuary is moved further inland to reduce impact on the ecosystem at the water’s edge. This relocation may also keep more of the trail above floodwaters more of the time. Access to prime viewpoints at the water’s edge is preserved via three trail spurs. • Rolling Contour Trail: Trails passing through hilly terrain are realigned off of fall lines and ridges to traverse sideslopes. There they are built with a full bench cut, frequent grade reversals, and moderate running slopes. This minimizes the amount and erosive force of runoff on any given section of trail. • Abandon and Re-vegetate: Abandon sections of the existing trail that are severely eroded, contribute negatively to erosive runoff, or are located in ecologically sensitive areas and then actively stabilize them through revegetation.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail System Concept: Built to Last
Uplands
Legend
3
Project Focus Area Campus Center Visitor Center
4
Existing Trail Abandon and Veg Moved Inland
By realigning trail sections in sensitive areas, such as this one that passes through the mangroves along the estuary’s bank, the redesigned system limits its negative impact on fragile ecosystems and is further from damaging floodwaters as well as the industrious crabs that routinely dig holes in the current trail. This is also a known habitat of crocodiles and should be respected as such.
2
Grade reversals like this one are a crucial element of rolling contour trail design that will help minimize the impact of heavy runoff on the Refugio’s trail system. When combined with a firm and stable tread and adequate outslope this form will provide the most durable and environmentally sound trail.
3
A well-compacted tread composed of material of various particle sizes will more effectively shed runoff and resist the erosive effects of use over the long run. In the Refugio, crushed basalt or other locally available, angular stone could be added into the trail tread to give it greater stability as well as enhanced traction for users.
4
On the CIRENAS campus across the road, deep-rooted vetiver grass is being used to stabilize raw slopes. This same approach, in combination with native tree cuttings and seeds, could be applied to abandoned trail sections as well as the backslopes of newly excavated bench cuts to increase their erosionresistance.
Not for construction. Part of a student project and not based on a legal survey.
1
June 30, 2015
Mangrove
Prepared By: Kate O’Brien & Dave Weber
Firm and Stable
Trail System concept II
Rolling Contour
North
17/21
Río Bongo
Río Arío
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Legend
Trail System Assessment
Project Focus Area Campus Center Visitor Center Trailhead Kiosk Existing Trail Rolling Contour Firm and Stable Northern Aspect Natural Shade Navigation Sign Ample Space Between Trail Segments
Tropical Dry Forest Wet Meadow
Mystery
Subtle curves, like the one pictured at left, as well as vertical variations and natural features such as large trees or boulders, help to break sight lines along a trail’s length. These visual obstructions divide the trail corridor into a string of distinct sections that may be enjoyed more fully one at a time. This has the added benefit of building users’ anticipation as they wonder what might come next around each bend.
Dune Grass
Surprise and Awe
Wherever possible, points of interest are approached in such a way as to obscure them until the last moment. In the example at left, the trail approaches a viewpoint overlooking the Río Arío from inland and downhill, which prevents trail users from seeing what is coming until they arrive. At that point, a user moves from the shadow into the light and the view is revealed suddenly, with maximum impact. This same effect can be created with built structures. For example, a raised platform built in the midst of dense, visually obstructive vegetation might yield an unexpected, commanding view from above.
Privacy
Sections of trail that run parallel to one another are kept horizontally and/or vertically far enough away from one another to provide their respective users visual and, whenever possible, audio separation. This preserves their individual experiences and allows them to more fully appreciate their surroundings. Spurs leading to points of interest also aid in this pursuit by enabling users who do not wish to visit a given point of interest to continue past it without disturbing other trail users who may be enjoying it at the time.
June 30, 2015
Beyond helping users make informed decisions about the length and difficulty of the trail they choose, this revised network seeks to provide ample sensations of mystery, surprise, awe, and privacy.
Mangrove
Not for construction. Part of a student project and not based on a legal survey.
Creating A Sense Of Adventure
Charral (Scrub)
Prepared By: Kate O’Brien & Dave Weber
*This design is strictly conceptual and is only meant to illustrate broad design principles. Any future trail construction must be preceded by further data collection, planning, and careful layout.
Estuary
Trail System concept III
Improved trail alignment and construction enhance the physical experience. Users are well-oriented as they navigate the trail system. • Loops On Top Of Loops: Four stacked trail loops offers visitors many more potential routes than the existing linear trail. This design also allows for sections of trail to be selectively closed for maintenance, while allowing users alternative routes. • Choosing An Experience: A system of trailhead kiosks and navigational signs at intersections orients visitors and informs them of the length, difficulty, and attractions of the Refugio’s different trails. With this information, users match their abilities and desires to a chosen route. These signs may also state expected standards of behavior in order to minimize conflict between users. • Staying Cool: Trails ascending the Refugio’s two hills capitalize on the additional shade available along their north sides. This is important given the relatively short charral scrub vegetation that is common on these hills, which does not provide adequate shade in many places. For the most part, points of interest and gathering spaces are located in areas providing natural shade. (The lookout atop the central hill and one at the far northwest corner of the Refugio lack sufficient natural shade and require the construction of shade structures.) • Creating Flow: The same firm, stable tread, and rolling contour design that help to limit trail erosion also provide users with a comfortable trail. Frequent grade reversals, designed to help shed water across and off the trail, double as level rest stops. These vertical variations as well as curves in the trail give it a pleasant, winding rhythm.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail System Concept: Matching Expectations With Experiences
North
18/21
6
Estuary Río Bongo
5
Río Arío
Legend
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
4
Campus Center Visitor Center
3
Trailhead Kiosk
Trail System Assessment
Project Focus Area
1
2
Existing Trail Natural Shade Point of Interest Major Attraction Existing/Open View Potential View Tropical Dry Forest Wet Meadow Charral (Scrub)
1
This view northeast up the Río Arío provides an excellent opportunity to educate visitors about watersheds as well as the power of rivers to change a landscape over time.
2
Shorter, denser charral scrub is prevalent, especially on the Refugio’s hills. This early successional growth contrasts sharply with the occasional large shade trees that indicate the area’s past use as a pasture.
3
Some views, including this one looking out towards the Pacific from the Refugio’s highest point, are partially obstructed by vegetation. A raised platform here would open up expansive 360 degree views for visitors.
4
Well-shaded, relatively flat areas like this one offer space for groups to gather to hold an outdoor class, spend time taking in a view or observing wildlife, or just to relax in the cool microclimate.
5
The high canopy and relatively open under story of the tropical dry forest in the Refugio’s northeast floodplain make it easy to spot birds.
6
Not for construction. Part of a student project and not based on a legal survey.
*This design is strictly conceptual and is only meant to illustrate broad design principles. Any future trail construction must be preceded by further data collection, planning, and careful layout.
From the top of the dune at the trail system’s northeast end visitors can enjoy expansive views of the broader landscape as well as mangrove, estuarine, dune, and marine habitats. A raised observation platform here would further extend these views.
June 30, 2015
Dune Grass
Prepared By: Kate O’Brien & Dave Weber
Mangrove
Trail System concept IV
The Refugio provides educational opportunities to visitors in the form of abundant and varied flora and fauna as well as views showcasing watershed dynamics, different innovative land management techniques, and varied landscapes. The revised trail system provides visitors with increased access to observe and engage with a wider variety of these assets than was previously possible. A system of interpretive signs provides insight into what users may encounter during their explorations. • Improved Access to Multiple Habitat Zones: The new trail system brings visitors through and, whenever possible, along the edges of the Refugio’s several different habitat zones including wet grassland, tropical dry forest, charral (dense thickets of early successional species), mangroves, and beach. This provides users the opportunity to observe and compare the ecological characteristics that define distinct areas. These may include different flora and fauna, topography, aspect, soils, and microclimates among others. This layout also limits the fragmentation of these habitat blocks. In particularly sensitive habitats such as mangroves, the trail accesses points of interest at the water’s edge via short spurs instead of following the riverbank as it once did. • Taking It All In: A series of viewpoints along the length of the trail give users opportunities to observe the Ríos Arío and Bongo and their combined watershed; the varied landscapes of the active ranch, new CIRENAS campus, beach, and estuary; as well as wildlife in different habitats. The majority of these viewpoints are located in existing, naturally shaded areas. Some (in pink) are already open. Others (in orange) require some clearing of vegetation or the construction of a raised observation platform to open. Three outstanding outlooks—at the bend in the river, atop the central hill, and at the northwest beach trailhead—serve as the primary destinations to draw visitors in. • Gathering Spaces: Areas identified as points of interest have ample shade and enough flat space to accommodate a group of people. These offer opportunities for user groups to gather for activities such as outdoor classes or simply to enjoy a rest. Many of these spaces feature notable views as well. • Interpretation: Signs located at points of interest and transitions between habitat zones provide visitors information regarding flora and fauna of the area as well as interpretation of the landscape features and processes visible from different viewpoints. Considering the likely trail user groups, these signs should be in Spanish and English (see Signs page).
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail System Concept: A Refuge for Wildlife and Learners
North
19/21
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Trail System Concept: A Shared Visitor Hub
June 30, 2015
Prepared By: Kate O’Brien & Dave Weber
Not for construction. Part of a student project and not based on a legal survey.
Food System Innovation Center
Trail System Concept V
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Settled between the Refugio and New Campus, the ranger station is a pivotal destination that can serve as the visitor center. The adjacent active pasture, backdrop of the dense forest within the Refugio and agricultural innovation across the way at CIRENAS’ new campus offer visitors the chance to observe a changing landscape, which can be described with further signage. In addition to location, the ranger station offers restrooms, ample gathering on an expansive porch, and tent platform, as well as space a long the road for parking. From the ranger station, stairs built into the steep hillside lead to the road where a gate marks the entrance. Across the road, a matching gate identifies the path to the CIRENAS campus and symbolizes the joint relationship between the CIRENAS and Refugio. At this gate, a small boardwalk traverses an existing drainage ditch and connects to stairs leading past a mango tree which visually anchors the path. The path advances past the food system innovation barn where visitors may engage in tours or activities to learn about sustainable agricultural practices. A shortcut from the road hugs the large lower pond offering relief from the oppressive sun and an opportunity to learn about water management. Finally, the path ascends to the dinning hall where an expansive view showcases the surrounding terrain.
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A “hooch” is a raised, shaded platform most often constructed of comparatively lightweight and sustainable bamboo and palm thatch. CIRENAS has expressed interest in growing bamboo for construction use. Palma royal, whose fronds are excellent for thatch roofing, is extremely common throughout the project focus area. This structure requires a minimal foundation and is supported by guy wires. This could help limit the amount of necessary excavation disturbance and concrete use. This design has been used successfully in other parts of Costa Rica, such as Rancho Mastatal, and could be a good option for creating a commanding 360-degree view from the top of the Refugio’s central hill. Expert consultation should be sought to determine the safe load limits of this type of structure.
An elevated platform located on the dune at the tip of the project focus area would give visitors a commanding view of the beach as well as much of the estuary, where birdwatching is excellent. Any structure installed on the beach should offer users shade. Further data collection and site analysis should be undertaken to determine whether there is a viable location on the dune that has not historically been overtaken by the river during high water.
June 30, 2015
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Trail System Assessment
There is potential to mount platforms to some of the large trees within the Refugio. In densely foliated trees such as guanacastes these platforms would provide trail users with opportunities to observe flora and fauna at different levels within the forest canopy. Platforms in taller, less heavily foliated trees might provide longer views of otherwiseinaccessible areas such as the Río Bongo oxbow. These platforms are common in Costa Rica, and a wide range of construction methods and materials are used. In heavy use areas, such as Monteverde Cloud Forest Reserve, metal is the preferred material. As is the case with the more conventional observation towers at left, transportation of building materials to and within the Refugio could be time and labor intensive.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
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Prepared By: Kate O’Brien & Dave Weber
A more conventional, cross-braced observation tower is another alternative to provide a raised viewpoint for visitors. A variety of materials could be used for construction including wood, metal, or composites. Of these, wood could potentially be harvested and milled within Hacienda Arío. As compared to the hooch, this type of structure requires a more significant foundation. The additional concrete and water necessary for construction of a conventional foundation might be avoided through the use of helical anchors or Diamond Piers. Because this type of structure is more common than the hooch, designs and engineering specifications may be easier to come by. Unlike the example at left, a tower in the Refugio should have a roof to provide users shade.
Observation Platforms
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Not for construction. Part of a student project and not based on a legal survey.
Free-standing or tree-mounted observation platforms give visitors access to views at different levels within the forest and offer longer, more expansive views over obstructions. They often serve as attractive destinations within an area that help draw visitors in and provide them with a satisfying reward. These structures can also provide shade and protection from the elements in places where there previously was none. Within the Refugio, there are several sites that could benefit from raised observation platforms: the lookout at the top of the central hill, the dune at the focus area’s northwest corner, and a number of very large trees. Of these, the central hilltop has the greatest potential to provide visitors with near-360-degree views of the entire Refugio and its surroundings. An observation tower there would provide a central main attraction for the Refugio trail system and would capitalize on the existing topography. Insect resistance will be an important consideration in the construction of any structure within the Refugio. This is one category in which metal holds a significant advantage over wood. That being said, teak and other termiteresistant timber may provide nearly equal longevity with the added benefit of being locally available and renewable.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Observation Platforms: A Little More Height Yields a Much Better View
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Signs: Interpreting a Rich Landscape
Directional Sign
Wildlife Inventory
Landscape Panorama
Interactive Sign
This sign provides specific information: distance, elevation, and the maximum and minimum elevation along the trail. Further information could include minimum trail width, surface type and firmness. Offering numerous trails within the Refugio will provide different experiences such as a flat trail along a boardwalk or a longer trail that traverses a hillside. These signs help visitors understand the form of the trails and judge which trail best matches their ability and expectations.
A display of local wildlife and vegetation can present facts about the species such as mutual relationships with wildlife or average annual growth. A sign similar to this example could be located at the visitors center to help visitors identify species they see, describe relationships between species and the environment, and encourage responsible use of the Refugio. The tiles can be changeable and represent sections of the Refugio by zone and season.
A large panorama of a specific view can be used to depict patterns within the landscape as well as significant points of interest. This design could be implemented where a view of the watershed shows the interaction between the rivers and the estuary. This sign could describe seasonal changes and identify the wildlife that lives there. A similar sign could be constructed on raised structures and platforms to describe the surrounding landscape.
Interactive signs with QR codes can allow visitors to listen to audio tours or post pictures to an online blog. Numbered signs would enable visitors to post pictures of specific locations in an organized fashion. This interactive use could help researchers track seasonal changes such as migratory birds and vegetation growth, and trail conditions.
June 30, 2015
A map of the entire trail system is beneficial for visitors to understand the relationship between trails. Visitors can determine their route based upon points of interest and the length of the trail.
Trail System Assessment
A covered sign is protected from precipitation and is more durable. Posting signs behind Plexiglas allows them to be easily updated. This design could enable visitors to share their pictures and experiences. Researchers could post information about current projects and discoveries.
Prepared By: Kate O’Brien & Dave Weber
Destinations Map
Signs
Trailhead Kiosk
Not for construction. Part of a student project and not based on a legal survey.
Signs should be installed to: • Identify National Wildlife Refuge • Help orient visitors • Interpret the landscape and flora and fauna
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Currently, the Refugio does not have any signs along the trails along the perimeter and at the trailheads of the Refugio will increase public awareness of the National Wildlife Refuge as well as the trail system. Within the Refugio, signs will improve user experience with information about trail difficulty and the destinations offered. Signs will aid navigation and can be used to provide information about flora, fauna, ecosystems, microclimates, unique features, typical communities and more. The signs shown here illustrate graphics, materials, designs and information with varying scales and styles. The Refugio will be visited by a variety of users including locals, foreign tourists, students and researchers. With this in mind,the signs should be multilingual and engaging for visitors with different levels of knowledge about the Refugio. The material and form of the signs should also be considered. The signs should be constructed from local materials that are resistant to termites, such as teak, or composites, such as Trex, which are made of recycled plastic. The signs can be displayed on a stand or within a larger structures such as a kiosk.
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June 30, 2015
Trail System Assessment
Considering the relative scarcity of large, hard stone in the Refugio’s vicinity, staircases should be built using more easily attainable materials such as wood and mineral soil. This example uses partially buried, halved logs to retain the sides or the soil-filled stair treads. While this example shows large stones being used to stabilize these logs, they could be secured using stakes of re-bar instead. The fronts of the stair treads consist of boards fastened on the ends to the log retainers.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Since many native species of trees are resistant to rot and insects, fallen trees could be salvaged and cut into pieces to make wooden “stepping stones” which could be used to provide a little extra elevation for trails in damp areas such as the wet meadow near the road. One half to two-thirds of these wooden chunks is buried to make them stable.
Prepared By: Kate O’Brien & Dave Weber
Simple bridges like this example could be constructed of locally harvested, insect resistant wood, such as teak.
Bridges, Boardwalks & Stairs
A raised boardwalk would keep visitors’ feet dry and protect the root systems of mangroves.
Not for construction. Part of a student project and not based on a legal survey.
The Refugio’s topography makes it likely that some portions of the trail system may require bridges, raised boardwalks, or stairs in order to provide visitors comfortable access. Additional topographical data and site analysis should be sought to better determine exactly where these structure could have the greatest beneficial impact. The following are best guesses based on site observation and conversations with individuals better acquainted with the landscape. • Trail segments through the mangroves running along the project area’s northeast and west sides (especially near the proposed southern beach trailhead) may require raised boardwalks to deal with tidal fluctuations, chronic wetness, and constant excavation by crabs. Boardwalks would also provide protection to the mangrove roots and sprouts, allowing visitors to explore this fragile ecosystem without trampling it. • In places such as the low point between the Refugio’s two hills, where it appears that water may collect, a bridge of some sort might be necessary to preserve access to the hilltop lookout and northern trails. This depends on how much of the year the Refugio trail system is to be open. • Along the proposed trail through the low, potentially wet, grassy area west of the ranger station, basic bog bridges or stepping stones (these could be wood as well) might suffice. • In the steep upland section of the Refugio, it may be necessary to install staircases in order to gain the necessary elevation to reach points of interest without making trails excessively long. By making the majority of the elevation gain with stairs, this alternative may make it easier to preserve a moderate grade along the trail segments between staircases, which is highly desirable for the construction of a rolling contour trail. As is the case with observation platforms, efforts should be made to source building materials for any of these structures nearby and from renewable sources whenever possible. These materials must be able to withstand exposure to UV, freshwater, salt water, termites and other insects, or any combination of the above. Locally harvested and milled teak may be a good candidate; however, if available, stone (large pieces) could be used for stairways and stepping stones where minimal extra elevation is needed to comfortably cross a damp area.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Bridges, Boardwalks & Stairs: Navigating the Soggy and the Steep
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The 3-Meter Stick: A Simple Tool For Critical Measurements
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Trail System Assessment Not for construction. Part of a student project and not based on a legal survey.
Using a 3-meter stick
Prepared By: Kate O’Brien & Dave Weber
spirit level 3-meter length of aluminum angle stock
Grade Reversals
What makes a 3-meter stick?
total length of reversal
entrance sl
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
A good trail builder walks softly on the land and carries a big stick, a 3-meter stick to be exact. One of the most important tools in a trail builder’s kit, it consists of a 3-meter length of straight, rigid material (aluminum angle is excellent given its light weight and high rigidity) and a spirit level held together with duct tape, rubber bands, etc. This tool allows a trail builder to quickly determine the percent slope of an area by resting one end of the stick on the uphill end of the area and raising or lowering the opposite end to find level. The trail builder, or a helper, then holds a measuring tape or meter stick vertically at the end of the stick and can then read the number of centimeters of decline over 3-meters. This value is then divided by three to yield the percent slope. This tool is particularly useful for laying out grade reversals because a trail builder can determine the point at which they wish to begin the reversal, place the end of the 3-meter stick there and then simply swing downhill until they find the point 10 to 16 centimeters below, thus determining the low point of the reversal.
June 30, 2015
Grade reversals are most often incorporated into a trail as part of its initial layout; however, in some cases, reversals may be added into existing trails. Of these options, it is preferable to design reversals into the layout by curving the trail slightly uphill or downhill. Doing so allows a trail builder to lay the trail out so that it responds to obstacles and attractions in the landscape while simultaneously managing runoff effectively. In addition, the resulting vertical and horizontal variations are what give a rolling contour trail its pleasing rhythm and flow. In those circumstances where an existing trail meets the necessary criteria, a reversal may be excavated into it in its existing alignment. This will result in a larger backslope, which may make additional stabilization necessary in order to avoid slope failure. In order to most effectively limit trail erosion in upland areas, grade reversals should be incorporated every 5 to 15 meters along a rolling contour trail’s length. This interval depends on the expected intensity of precipitation in an area as well as the natural slope of the terrain and the running slope needed to reach a destination. In areas experiencing very heavy precipitation, such as the Refugio, a shorter interval between reversals is preferable as it will help limit the erosive force exerted on any given trail segment by runoff. While the overall interval between grade reversals may vary considerably, some dimensions are less flexible and will help ensure that the reversal manages runoff effectively. These include the following: • The reversal ramp should be at least 3 meters long and drop 10-16 centimeters. This will help guarantee that even the heaviest runoff will not overtop the reversal and continue down the trail (this should be ameliorated as long as the trail has an adequate outslope of 5-8%). • The entrance slope is the average slope needed over the course of a climbing trail segment to reach the desired high point. This should not exceed 10% unless absolutely necessary. Given the tremendous intensity of the rain the Refugio trails are likely to experience, it is of great importance that grade reversals be spaced at as short an interval as possible. If the entrance slope exceeds 10%, either the exit slope must increase in order to rejoin it, or it must be feathered back over a much longer interval, neither of which is desirable. • The exit slope should not exceed 15%. Running slopes in excess of 15%, especially in areas with extreme precipitation, will most likely require the hardening of the trail’s tread with pavement, cement, or brick pavers. By keeping the steepest part of a reversal under 15%, a trail builder may avoid these more environmentally costly materials and maintain a more comfortable slope for users.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Grade Reversals: Shallow Dips Have a Deep Impact on Drainage
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Mineral Soils
Tread
Critical Edge
Mineral Soils
Clay Soils
The Right Soils Make All The Difference Although soil profiles were not dug along the Refugio trails, this photograph shows the soil profile on one of the hills in the new CIRENAS campus across the road. This may serve as a reasonable approximation of what the soils in the Refugio’s uplands look like. The relatively thick (approx. 1/2 meter) layer of mineral soils is particularly notable. This is the layer that will provide the best base for trail tread and its thickness will provide flexibility to the process of bench cutting. The soils below this layer, which are noticeably grayer with streaks of red, are most likely much higher in clay, which is both poorly graded and drained and should be avoided.
A Note On Tree Roots and Trails Whenever possible, a trail should be laid out so that it climbs above trees instead of dipping below them where a bench cut will undermine or cut into the tree’s roots, leading to its death. There is often already a bit of a natural bench on the uphill side, which will require less excavation. That being said, roots are an inevitable reality of trail building. Where tree roots run perpendicular to the trail’s tread and do not pose a tripping hazard, they should be left. Roots that run parallel to the trail’s alignment in the tread should be cut cleanly and removed because they will prevent water from draining across the trail, which will result in puddling and/or erosion.
Full Bench Cut
Organic and Mineral/Organic Horizons
Not for construction. Part of a student project and not based on a legal survey.
Clay Soils
June 30, 2015
Trail System Assessment
Center Line
Prepared By: Kate O’Brien & Dave Weber
Organic and Mineral/Organic Horizons
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Coconut fiber matting could be used to stabilize slopes where it is impossible to achieve the angle of repose.
B
The purpose of a full bench cut is to provide a stable, relatively level foundation of undisturbed mineral soil for a trail’s tread. The process of excavating a bench does cause a significant disturbance to an area, so it is important that it be done carefully, following adequate analysis of site conditions. (For a more detailed description of this and the steps outlined below, please refer to the trail construction and maintenance guides listed in the references section.) Once site conditions have been deemed appropriate for excavation, a trail builder should follow these steps to create a full bench: • Mark the centerline of the trail tread with pin flags or stakes • Using a pick maddock or other digging tool, mark the uphill edge of the proposed tread as measured horizontally from the center stake (not along the ground surface). • Starting from this line and working back towards the centerline, remove all organic material (leaf litter, duff, and soils containing organics) from an area the full width of the proposed trail tread. This material should be spread on the downhill side of the trail corridor in a way that will not negatively impact vegetation. Don’t dump it all in one big pile. Instead, spread it more or less evenly over a large area. • Starting from the downhill edge, begin digging back towards the centerline of the trail. Be careful only to remove organic material and soils with organics mixed into them at this point. The idea is to expose the mineral soil layer and create a roughly level bench without digging too deeply to begin with. • Roughly level off the area of exposed mineral soils. Excess mineral soils may be stockpiled for use filling in holes left by stumps etc. or spread downhill as mentioned above. There should now be a roughly square angle at the uphill edge of the tread. • Carefully cut the backslope until it reaches the angle of repose or, in steeper terrain, try to achieve a minimum of a 1:1 slope. Where it is impossible to reach the angle of repose, it may be necessary to stabilize the face with vegetation, stone, or timber. There are excellent mats made of coconut fiber that not only serve to stabilize themselves, but also act as fertilizer for vegetation that is interplanted in them. If available these might be an appropriate, biodegradable option. • The next step is to carefully begin outsloping the tread to roughly 5%. This should be done starting from the outside of the tread working back towards the inner edge. • If necessary, add material such as crushed stone to create a more firm and stable tread texture (well graded soils). Compact evenly. • Clean and round off the critical edge at the outside of the tread. This will allow sheet drainage to run easily off the tread. Failure to sculpt this smoothly is one of the leading causes of water running down trails, causing erosion. With that in mind, it is also important to remember that this outside edge is perhaps the most important part of a trail to maintain consistently (see following sheet for further details).
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Full Bench Cut: This Bench is Made for Walking
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Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
If left on the trail tread, biomass like the leaves shown here creates a slipping hazard, even during the dry season. In addition, as they biodegrade, the organic material becomes mixed into the tread material, weakening it.
Trail closures during peak rainy season may help prevent wear and tear when heavy downpours put even the best-built trails at high risk of erosion.
June 30, 2015
Trail System Assessment
Once outslope is re-established, special attention should be paid to reforming the critical edge.
Prepared By: Kate O’Brien & Dave Weber
Original Outslope
Mineral soil should be returned to the tread, regraded to the original outslope, and compacted.
Maintenance
In order to maintain an open trail corridor, especially along trail segments passing through dense charral like the example at left, frequent pruning will be necessary. In areas where the trail is bench cut, it may be helpful to leave vegetation along the outer edge a bit closer. This will encourage hikers to use the inner portion of the tread, which will help prevent damage to the critical edge.
Any vegetation and organic matter should be removed from the critical edge to expose the berm.
Not for construction. Part of a student project and not based on a legal survey.
Regular maintenance is a critical component of a trail’s sustainability over the long term. If left untended, even the most durably built trails will eventually succumb to erosion, which will detract from their users’ positive experience or potentially render them unsafe for use at all. In many cases, frequent, minor maintenance may be adequate to prevent the need for large scale interventions. The following are some of the most important steps for a maintenance team to address on a regular basis: • Re-establish tread outslope: This is the single most effective step to prevent erosion from occurring. Normal trail use will tend to shift biomass and tread material toward the tread’s critical edge where it will begin to form a berm. This berm, if left in place, will prevent water from sheeting across and off of the tread. Instead, it will concentrate and either puddle or run down the trail, causing erosion. This berm should be cut down in two steps. First, any organic material or vegetation should be removed and discarded down slope. Second, the tread material should be scraped back onto the tread, regraded to the original outslope, and compacted. The final step is to reform the critical edge to ensure that water flows off the tread uniformly. • Remove biomass from trail tread: Leaf litter and twigs should be regularly swept off of the trail tread. This will not only prevent them from becoming a slipping/tripping hazard, but also from blocking drainage flow across the tread. • Prune vegetation along the trail corridor: Keeping an open corridor of adequate size requires frequent pruning, especially where vegetation is fastgrowing. In the Refugio this is particularly important in the uplands where charral scrub may quickly overgrow the trail if left unchecked. • Close Trails during high risk periods such as peak rainy season: Sometimes the best way to maintain a trail for use is to prevent it from being used. The extremely heavy downpours that occur during peak rainy season are likely to cause some erosion of even the most durable trails. Closure of some or all of the trail system during this period will not only prevent hikers from compounding the problem with additional wear and tear, but also allow maintenance staff to address erosion as it occurs.
332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Maintenance: Keeping a Good Trail in Good Shape
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
June 30, 2015
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Prepared By: Kate O’Brien & Dave Weber
It is necessary to identify a starting point from which all other points are measured. This enables another person to accurately find the location. It is important to note the distance between two points in order to assess slope and with regard to required spacing for trail components such as resting areas and grade reversals.
Data Collection I
Trail layout occurs after site analysis, and initial design has been competed. Layout is the process of marking out a proposed trail. Ground truth the control points identified in the Planning Report and take note of additional opportunities or constraints. Walk the proposed trail at least once and note patterns such as topography, vegetation and drainage. The next step is to flag the trail. Information about flagging a trail can be found in Larry Lechner’s trail guide. After preliminary routes have been flagged, evaluate the alternatives and encourage new perspectives from people who have not been involved in the layout. When the best alternative is chosen, remove all excess flagging and begin staking out the trail. A GPS or rolling wheel can be used to mark and define points along the trail. Taking a picture at every point is ideal and recording the number of the photo is beneficial for organizing and locating pictures. Information about staking the trail can be found in Larry Lechner’s trail guide. Slopes can be measured with a 3-meter stick as previously described. Areas with severe or flat slopes should be avoided. Steep slopes can exacerbate erosion and trails in flat areas generally require more maintenance than trails along varying elevations because it is more difficult to drain water off them.
Point #
Trail Name Date
Trail Layout
Point Description
Distance from
Segment Length
Slope
Photos
Opportunity or Constraint Observations
Data Collection: Trail Layout Sheet
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
June 30, 2015
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Prepared By: Kate O’Brien & Dave Weber
Trail monitoring—evaluating trail conditions— is a are fundamental component of trail management. Trails should be monitored for social and biophysical conditions. Examples of social impacts include visitor conflicts, litter, and unwanted widening of trails caused by users leaving the marked trail to avoid puddles. Erosion, sedimentation, water body contamination and wildlife disruption are all examples of biophysical impacts. Other impacts to observe include loss of outslope and/or backslope, brush or material in the trail, missing or deteriorating signs, and tread washout. Record each point, and include the monitoring objective for that area such as why the area is being monitored, and how the information being derived will be used. A description of the condition, photo and any additional notes help to organize data and denote changes over time. Condition can be described in words such as: • no damage • little damage • moderate damage • severe damage or numbers: • 0=no damage • 1=little damage • 2=moderate damage • 3=severe damage Further information about trail monitoring including how to determine what to look at (indicators) and how to evaluate what you are looking at (standards) are provided in Larry Lechner’s report.
Data Collection II
Observer's Name Date Trail Name Point #
Trail Monitoring
Monitoring Objective
Monitoring Frequency
Condition Report
Photos
Notes
Data Collection: Trail Monitoring
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
June 30, 2015
Trail System Assessment
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Prepared By: Kate O’Brien & Dave Weber
Data Collection III
A sign-in sheet helps to determine trail use, where people are coming from, intensity of and why they are visiting. This can be used as a tool for increasing visitation to the Refugio by determining where people are coming from and reaching out to those areas by posting signs or brochures about the trail system. The comments section allows users to comment on trail conditions and places of particular interest. The Refugio Ranger can refer to the sign-in for updates on trail condition. Users’ comments can also help CIRENAS to promote the highlights of the trail system such as particular views, vegetation and structures favored by visitors.
Date
Trailhead Sign-In Form
Name
City, County of Origin
# In Party
Reason for Visit
Comments
Data Collection: Trailhead Sign-In
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Resources The manuals listed below were instrumental in the formulation of this document. Each guide addresses trail planning, design and construction and should be consulted prior to any trail redesign.
The USDA Trail Construction and Maintenance Notebook describes fundamental trail planning, design and construction. This guide includes detailed illustrations for trail construction and further information about surface water control, and designing trails in wet areas. The guide also includes a section about installing and maintaining signs and reclaiming abandoned trails.
Massachusetts Department of Conservation and Recreation. Trail Guidelines and Best Practices Manual. 2010. MS. N.p.
The Department of Conservation and Recreation Trail Guidelines and Best Practices Manual describes how to assess and plan an existing or new trail, the principles of ecologically sustainable trail, trail maintenance, mapping, and signage. This guide includes definitions for trail terminology, a trail proposal and evaluation form, and volunteer work log.
Expert Consultant Peter provided valuable insight and instruction regarding site analysis including data collection and trail planning theory and practice. He is a renowned designer/builder/ educator and is known as a leader in the development of accessible trail policy and design.
Websites http://www.vetiver.org/g/slope_protection.htm
Information about how Vetiver is used for soil stabilization to reduce erosion. The website includes plant management and implementation stories.
Resources
Peter S. Jensen Trail Planner/Builder LLC Managing Member/Partner Peter S. Jensen & Associates, LLC www.trailbuilders.com
June 30, 2015
Hesselbarth, W., B. Vachowski, and M. A. Davies. “Trail Construction and Maintenance Notebook. USDA, Forest Service.” Technology & Development Program, US Department of Transportation, Federal Highway Administration, Recreational Trails Program: http://www. fhwa. dot. gov/environment/fspubs/07232806/index. htm (2007).
Trail System Assessment
This manual presents guidelines for planning and constructing trails in primarily natural settings with an emphasis on protected areas in Brazil. The guide discusses trail experience, and includes a step-by-step process for designing trails from planning through construction. The definitions for the Illustrated Glossary were taken from Lechner’s Glossary of Trail Terms. This manual should be used as a reference for further information including tools, budgeting and cost estimating, and trail layout.
Prepared By: Kate O’Brien & Dave Weber
Lechner, Larry. Trail Planning, Construction and Maintenance in Parks and Protected Areas. 2003. MS. N.p.
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
Trail Building Manuals
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332 S. Deerfield Road | PO Box 179 | Conway, MA 01341 413-369-4044 www.csld.edu
Photo Credits
Google Earth
Visitors and Access • Orthophotograph • CIRENAS students at ranger station • CIRENAS students with schoolchildren • Birdwatchers
Google Earth www.cirenas.org www.cirenas.org https://en.wikipedia.org/?title=Birdwatching#/media/File:Birders_at_Caerlaverock.jpg
Climate and Watershed • Relief map • Monthly rainfall graph
Bing Maps http://nicoyapeninsula.com/weather.php
Observation Platforms • Hooch • Conventional tower • Tree platform • Beach platform
http://www.tropical-treehouse.com/hooch%20true%20believer%20slide%20show.html https://abcbirds.wordpress.com/tag/ecuador/ http://costaricaexpeditions.com/Gallery/singlepicture.php?pic=109 http://grandcitiesbirdclub.weebly.com/kellys-slough.html
Signs • QR code sign • Wildlife inventory sign • Panorama sign
http://www.countynewscenter.com/news/smartphone-fitness-hits-county-parks http://www.mageemarsh.org/birdingtips.html http://www.caribbeanbirdingtrail.org/sites/saint-martin/etang-de-la-barriere/
Bridges, Boardwalks, Stairs • Mangrove boardwalk • Wooden stepping stones • Bridge • Staircase
https://www.flickr.com/photos/certified_su/5795842345/ http://www.geograph.org.uk/photo/2329204 https://commons.wikimedia.org/wiki/File:Small_footbridge.jpg https://commons.wikimedia.org/wiki/File:W060326_lighthouse_park_006_adj.JPG
June 30, 2015
Project Site History • Orthophotographs
Trail System Assessment
www.anywherecostarica.com/regions/nicoya-peninsula/maps Bing Maps
Prepared By: Kate O’Brien & Dave Weber
Client and Project Scope • Nicoya peninsula map • Relief map
Photo Credits
Source
Not for construction. Part of a student project and not based on a legal survey.
Page Title and Image Description
Refugio Nacional De Vida Silvestre Caletas-Arío Puntarenas, Costa Rica
All photographs and drawings not listed below were taken or produced by Kate O’Brien or Dave Weber.
North
31/31