Ashuelot Greenspace Landscape Plan

Index

Ashuelot Greenspace Landscape Plan Michele Carlson & Gallagher Hannan The Conway School Spring 2014

1. A Vision 2&3. Ashuelot Greenspace Design 4. Analysis: Context 5. Analysis: Access and Circulation 6. Analysis: Hydrology and Stormwater Management 7. Analysis: Views, Sun & Shade 8. Analysis: Soils 9. Design Details: Entrance and Pocket Park 10. Design: Details The Pavilion 11. Design Details: Meadow and Parking 12. Design Details: The Woodland 13. Design Details: The Rocky Range 14. Alternative: Residential Development 15. Construction Details: Planting Plan 16. Construction Details: Grading Plan 17. Construction Details: Hardscapes and Swales 18. Construction Details: Play Features 19. Implementation and Phasing 20. Example Timeline 21. Conceptual Cost Estimates 22. A Glimpse into the Future 23-28. Appendices

What kind of community asset could this abandoned parking lot become if the asphalt were removed and it was brought back to life?

In 2013, three citizens of Keene, New Hampshire, bought this 3.5-acre property with that very question in mind. This document shares a vision for the site’s future.

A Vision

1

This is part of a student project and not for construction.

A new vibrant greenspace for the residents of Keene, a place to: Play.

Children play and explore the entire site. Different areas, surfaces, environments, and challenges help them connect with the natural world.

Explore.

Boaters enjoy easy access to the river, and maps invite passing cyclists and other visitors to explore the surrounding area, and the beautiful Ashuelot River Park.

Power.

Solar panels provide renewable energy for the city.

Shop Locally.

On market days, residents shop for local produce, prepared foods, and crafts at the Keene Farmers Market.

Connect.

The pavilion becomes an event space, where the community can come together to enjoy concerts, outdoor movies, or public art displays.

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Reflect.

Quiet nooks and shady edges offer visitors secluded areas to look out over the meadow and river.

Thrive.

Native vegetation creates habitat for insects, birds and animals.

Learn.

Interpretive signs teach residents about the history and ecology of the area, and about the site’s green infrastructure.

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

The Ashuelot Greenspace Design

2

This is part of a student project and not for construction.

It’s a natural playspace for children and adults to explore and enjoy.

Ashuelot Cour t

Ashuelot River Park

The Woodland

Solar Panels

For details see sheet 12

The Meadow For details see sheet 11

t

Overflow Parking Lo

Main Parking Lot

The Pocket Park For details see sheet 9

The Rocky Range

Discovery Path

A narrow 2.5' trail invites children to explore the site.

Bike Trail

Ashuelot River

For details see sheet 13

The Pavilion

Green Roof Solar Panels ion

Access to the Pavil

0

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

60

Connecticut River Bank Employee Parking

Ashuelot Greenspace Landscape Plan Keene, NH

Ashuelot Street

For details see sheet 10

For children, active exploration of a natural landscape: • Stimulates learning.

• Improves coordination.

• Decreases occurrence of sickness • Fosters language and collaboration.

• Provides a sense of freedom • Develops courage.

• Builds a sense of caring towards the earth and the need to act responsibly towards it.

• Cultivates an understanding of fellow creatures.

The Ashuelot Greenspace Design

3

Residential Neighborhood

Ashuelot River Park

The park is easily accessible to the large residential neighborhood to its east and provides plenty of greenspace for residents to enjoy.

The new greenspace serves as a gateway into the 175acre Ashuelot River Park, and a recreational hub for boaters, bikers, and hikers, by introducing visitors to the ecology of the river and providing amenities such as parking, drinking water, bathrooms, and maps of the area.

Peek into the Past Site

1898

Boat Launch for Kayaks and Canoes

Throughout the 1800s the site shared a boundary with the Falkner & Colony millpond.

Access to a popular launch point is created for boaters looking to explore the Ashuelot River.

Jonathon Daniels Bike Trail

This bike path connects with a greater regional network of bike paths stretching as far as the Vermont and Massachusetts borders.

The Site

Faulkner and Colony Dam The greenspace provides historical information about the nearby Faulkner & Colony Dam, which once created power for the Faulkner and Colony Mill, on West Street, while demonstrating new sources of renewable energy with it’s solar panels..

Ashuelot Arboretum The greenspace is an extension of the nearby popular, but quiet and contemplative, Ashuelot Arboretum, providing additional space for relaxation and creating space for play and active recreation.

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Commercial Area and West Street The park is near a large commercial zone, and West Street, which is a central corridor in and out of Keene, making it a suitable place for a farmers market.

Downtown Keene The park is within walking distance of downtown Keene (1/2 mile) making it a central location for community events.

Analysis: Context

4

This is part of a student project and not for construction.

Because of the site’s central location in Keene, it is perfectly situated to become an active community hub and center for education, relaxation, and recreation.

Proposed Design

Existing Access and Circulation • • • •

Ashuelot Court

Ashuelot River Park

The vehicular entrance to the Ashuelot Greenspace is along the eastern side, off Ashuelot Street.

Pedestrians and bikers primarily access the site from the east, off the Ashuelot Street sidewalk, and to the west, from the Jonathan Daniel’s bike trail.

A low area to the west of the site serves as a boat launch. Boaters must carry their boats from the front of the bank.

Residents of the neighborhood to the east use the site as a cut-through in and out of the Ashuelot River Park..

g for Overflow Parkin s es cc A Visitors and to Boat Launch

Proposed Access and Circulation • • • • • •

Vehicles of visitors to the farmers’ market and the Ashuelot Greenspace enter the parking on the eastern side of the side: 56 parking spots, 2 handicapped spots.

Farmers market vendors enter their own parking/drop-off area at the back of the bank parking lot. Their lot is used several times a week, seasonally. The entrance can be locked when not in use.

Passers-by are invited into a small pocket park on the southeastern side of the site. Pedestrians can still enter from the west or the east, so accessing the Ashuelot River Park from the residential neighborhood is still possible.

Approximately 200 feet from the boat launch, space is provided to back up a vehicle to load or unload a boat. A pedestrian trail leads from the parking directly to the launch.

On the western side of the site near the pavilion there are bike racks, as well as a map to orient out of town visitors to the city.

Visitors to the Ashuelot Greenspace follow a loop trail around the park that provides multiple points of access into the residential neighborhood and the Ashuelot River Park and Arboretum.

Small children experience different views and textures on children’s trails that wind throughout the park, connecting different nooks and play areas.

Jonathon Daniel’s Bike Trail

•

Main Parking for Visitors

Pavilion

ndors of Parking for veMarket s’ the Farmer

Legend Vehicular Movement Cyclist Movement

Ashuelot Stre

et

Existing Conditions

Pedestrian Movement Pedestrian Gathering Area Children’s Trails Child Gathering Area (Play Area) 0

120'

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Bank Employee Parking

Arboretum 0

30'

60'

120' Bank

Boat Launch Ashuelot Greenspace Landscape Plan Keene, NH

Analysis: Access and Circulation

5

This is part of a student project and not for construction.

The site is especially designed for playing children and other people on foot; most vehicles are kept on the periphery.

Vendors for the market and boaters have access to the pavilion and the boat launch, respectively, and plenty of parking is available for visitors.

Existing Hydrology & Stormwater Management • • • • •

Proposed Design 100-year floodline

All the stormwater on the site flows into two storm drains and a culverted stormwater channel, which empties untreated about one mile south into the Ashuelot River.

The site’s impermeable asphalt prevents most infiltration on site.

The northeastern corner of the site has a clay pocket beneath the fill and is poorly draining.

The water table is very high on the site, especially on the western side near the river (for more information see Appendix C).

The 100-year floodzone covers most of the site.

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Proposed Hydrology & Stormwater Management • • •

•

473

47

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472

a Sw

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•

Infilt Filtraration and tion M eado w

a Sw

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•

Stormwater draining from the parking lot to the northeast is directed down a gentle slope through shrubs and a native wildflower meadow, slowing, cooling, and infiltrating the water.

The water that doesn’t infiltrate gathers in a rocky swale, in the center of the site, where it is filtered and infiltrated further, including through wetland plants.

In large storm events, or during the wet season when the water table is especially high and drainage is poor, excess water enters the culverted stormwater channel, having been filtered through plants to remove contaminants.

Grading on the northeastern side of the site directs poorly draining areas toward better draining, sandy soils, and if necessary, the stormwater culvert.

Water from the farmers market area drains into a swale, where it is filtered and infiltrated. Excess water enters the stormwater channel underground.

Water from the farmers market area parking drains south, into an infiltration basin along its southern side.

Permeable soil throughout the site allows water to infiltrate and recharge the groundwater.

The pavilion should be designed to withstand floods.

47

•

This is part of a student project and not for construction.

Asphalt is removed, stormwater is filtered through layers of vegetation and gravel to clean it of contaminants, and permeable surfaces allow it to infiltrate and recharge the watertable.

Swale

Existing Conditions

Rain Garden with Overflow Pipe

Legend Water Movement Suspected to be poorly draining

0

120'

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

0

30'

60'

120'

Suspected high water table

Ashuelot Greenspace Landscape Plan Keene, NH

Analysis: Hydrology & Stormwater Management

6

Proposed Design

Existing Sun, Shade and Views •

The site is predominately sunny, with small shaded areas around the periphery where vegetation has grown up outside the asphalt.

There is a narrow view out to the river, but the best views up the river are blocked by dense vegetation.

•

Solar Panels

No trees taller than 25'

Proposed Sun, Shade and Views • • • • •

Clumps of trees are planted to penetrate into the core of the site and provide shade, although staying close to the periphery as vegetation will be hard to establish in such poor soils and direct sun.

While most existing trees around the periphery remain, the dense line of white pines to the east are removed, allowing better views into the site.

North of the pavilion a clump of trees provides shade and allows for a comfortable seating area.

Solar panels on the southern half of the roof of the market and in the northern parking lot take advantage of the site’s sunny southern exposure.

Visitors are able to look up the river, due to the removal of low shrubby plants and some trees (for more information about vegetation and plantings see sheet 15)

No trees taller than 45'

No trees taller than 65’ Existing Conditions

Solar Panels

Shade Legend 9 AM Noon 3 PM 0

120'

Summer Solstice

0

30'

60'

120'

Views Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Analysis:Views, Sun & Shade

7

This is part of a student project and not for construction.

With more trees planted, more shade is provided on parts of the site. With the exception of the white pines along the east, existing trees along the site’s borders remain, while shrubs and understory are removed to open up views to the river and arboretum.

1’

1.5' Fill w/ small stones

2’

1.5' Very sandy (may be earlier fill)

Soils on site will need to be amended with organic matter in order to support vegetation. This could happen slowly, over time, or by bringing in compost and topsoil. Soils are, for the most part, sandy and well draining, although there are pockets of clay that create poorly draining areas.

3’

Thin organic layer with signs of high water table 1' Very sandy

4’

Existing Soils:

Water accumulation 1”

Possible Soil Amendment Options:

Pit depth 4.6'

Soil building on-site:

Pit 1

2-3" Asphalt Signs of a perched water table (clay is poorly draining) 3' Fill

1’

2’

Importing Soil:

2-3 inches

This is part of a student project and not for construction.

2-3" Asphalt

Fill is removed from site to balance organic soil that is brought in.

Large chunks of granite (most likely) to stabilize clay

3’

5" Clay with organic matter

4’

Clay

Pit depth 4.5'

Pit 3

2-3" Asphalt

1’

1.5' Fill w/ small stones

2’

1.5' Very sandy (may be earlier fill)

3’

Thin organic layer with signs of high water table 1' Very sandy

4’

Water accumulation 1” Pit depth 4.6'

2-3" Asphalt 1’

2’

Signs of a perched water table (clay is poorly draining) 3' Fill

Soils have been heavily impacted, and evidence shows that native soils have been buried under several layers of fill for over 40 years. Removing all the fill, and restoring the site to a wetland would be an expensive and energy intensive process and would leave the site very seasonally wet.

Instead, it is recommended that fills are amended increase organic matter, and plants are chosen that can tolerate these conditions. *For more information about soil pits see Appendix C.

3’

Clay

No water accumulation but the bottom

Ashuelot Greenspace Landscape Plan Keene, NH

6”-1’ of compost or topsoil could be brought in from off-site and laid over the entire site. Individual plants may need more organic matter around their roots.

Note: Bringing in topsoil or compost is complicated by FEMA floodplain regulations that stipulate any fill added to a floodzone must be balanced by an equal amount of cut to preserve flood storage capacity. The removal of 2-3” of asphalt across the site, will allow for some organic matter to be brought in without having to remove fill, but anything more will require trucking fill off-site, an expensive option.

Soil pits dug on site on June 3rd, 2014, showed 2-3" of asphalt over a varying amount of gravelly, sandy, stony fill (1'-3' deep). The soils underneath were very sandy, with layers of organic matter (most likely buried wetland soils) and signs of earlier filling as well. Pockets of clay were also found on site creating poorly draining areas.

Large chunks of granite (most likely) to stabilize clay

5" Clay with organic matter Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014 4’

As soon as possible, 2-3" of compost (the amount of soil that could be brought in under FEMA floodplain regulations after asphalt is removed) could be brought in and tilled into the fill, then planted with cover crops or a tolerant biomass-building meadow mix (such as Ernst’s Native Biomass Mix for Strip Mines) to build biomass on site.

No water accumulation but the bottom of the pit was wet

A compost program could be started on-site by a nearby professional using wood chips and leaves from the Keene Public Works Department or food scraps from the farmers market. *For more information about how to integrate soil building into the implementation and phasing of the project, see sheet 21.

Analysis: Soils

8

from Ashuelot Street, is easily accessible for residents of the neighborhood. The sidewalk curves gently away from its existing route up Ashuelot Street, inviting passers-by to come sit for a while in one of the many benches lining the path. A large vertical boulder provides visual interest on the street, and children peeking through the grove of white birches can see a maze of logs and the entrance to their own narrow, child-sized, pea-gravel path. The vegetated

This is part of a student project and not for construction.

The Pocket Park which serves as the main entrance

entrance, with its trees, tall grasses, and shrubs, provides some enclosure, but beyond, it is possible to see the park opening up into a large meadow with a grass-roofed farmer’s market pavilion. Once inside the pocket park, the benches beyond the trees afford views across the meadow and the boulder field and out towards the river.

A human sundial allows visitors to tell the time with only their bodies and the help of the sun, and an interpretive sign introduces visitors to the greenspace (see Appendix A).

Meadow

Greenspace

Lawn

Ashuelot

Wood and Stone Benches

Street

Passers-by are invited into the pocket park to sit for a while, and enjoy views of the greenspace and the river.

Interpretive Sign

Log Maze

Human Sundial

Wood and stone benches are placed to provide views out over the park and towards the river.

Farmers Market Pavilion

Log Maze

Existing S

Human Sundial

idewalk

Park Sign

Boulder Upright logs become a maze for children.

(For details see Sheet 18.)

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Visitors standing on the human sundial can consider the power of the sun, while using it to tell time with their shadows, and gazing up at the solar panel array in the distance. (For details see Sheet 18.)

Ashuelot Greenspace Landscape Plan Keene, NH

Design Details: Entrance & Pocket Park

9

of the site. The space is easily accessible from an entrance off the Connecticut River Bank parking lot. Approximately 17 parking spaces are provided south of the pavilion so that vendors with larger, heavy products can back their vehicles up to the stalls, while others can drop off wares and park nearby. Visitor parking is in the northern side of the site. The pavilion is a long open-air structure, with a grass roof on the north, designed to integrate seamlessly into the meadow, and solar panels on the south, generating energy for the market and other events, and revenue to help maintain the park. To the northwest of the market is a circle of trees, that provides

This is part of a student project and not for construction.

The Pavilion for the Farmers Market is located along the southern boundary

a shady spot to relax and eat, and where parents can easily watch their small children in the adjacent play area. The area features a hand pump for play, with non-potable water, that runs into a vegetated swale, carrying overflow from the pavilion’s roof down, under a small wooden bridge, to the rocky swale in the center of the site. The swale’s vegetation and a low mound, enclose the seating area, but still provide views out towards the river and the meadow. A bike rack and composting bathrooms (one already existing in the arboretum, one added) are provided at the entrance near the arboretum. By running a water line into the site from the street, water is provided for the market and bikers and park visitors.

Small Children’s Play Area with Hand Pump

il Tra

A Wooden Bridge

Seating Area for Farmers Market

Swale

The Pavilion is open-air with PV panels for solar energy on its southern side and a grass roof on its northern side to relate to the rest of the greenspace.

Green Roof

Solar Panels

Bike Rack

Access and Parking for Pavilion

A small wooden bridge extends across the dry creek and connects the trail to the seating area.

Rain Garden

A’

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Pavilion

Parking and Access for Market Vendors Ashuelot Greenspace Landscape Plan Keene, NH

Rain Garden

Lawn

Swale

A

Swale

1% slope

Bank Parking (off-site)

A small children’s play area features a hand-pump and small logs and stones for crawling and balancing on. (For details see Sheet 18.)

A'

Design Details: The Pavilion

10

slows and infiltrates stormwater from the adjacent and slightly higher parking lots.

Among the meadow grasses and flowers, pollinator plants, provide splashes of color and attract birds and insects, including butterflies and hummingbirds. The tall 3-4’ vegetation provides enclosure along the children’s paths. Large stone slabs are placed on stone bases for unique seating along the main path through the meadow. Above the meadow are two parking lots in a L-shape. The lot to the east is constructed of

This is part of a student project and not for construction.

The Meadow serves several purposes. Aside from its aesthetic appeal, it

gravel and is easily plowable to be used year round, while the lot to the north provides reinforced turf overflow parking for market days and events and a central gravel aisle, providing access to the boat launch. At the end of the overflow parking is an area to load and unload boats. A one-hundred-foot solar panel on the northern side of the overflow lot takes advantage of the sun streaming over the meadow, and provides shade, power for the town, and revenue for the park. Additional solar panels could be placed in this parking lot for additional power and revenue.

A Solar Panel Shade Structure for Parking

Overflow Parking

Loading/ one Unloading Zunch a L t a o B for

The overflow parking lot has a central aisle of gravel to clearly lead visitors to the boat launch loading zone and parking spaces of reinforced turf.

Main Parking Lot

Granite Bench

Trail

Children’s Path

Willow Arch

A willow arch provides an intriguing entrance for children entering the children’s path. (For details see Sheet 18.)

Rocky Swale A’

1% slope

Children’s Path

Meadow

Trail

Shrub Buffer Bench

Trail

2% slope

Reinforced Turf Parking

Granite Benches are carefully sited to provide views of the meadow.

PV Panels Reinforced Turf A'

A Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Gravel Lane to Boat Launch

Ashuelot Greenspace Landscape Plan Keene, NH

Design Details: The Meadow & Parking

11

is the closest area to the river, and borders the Ashuelot River Park. Here the children’s path passes through a sumac grove, and then through a doorway carved from a large tree stump, marking the entrance into a woodland play area. Tree stumps and logs of various heights and sizes provide a balancing challenge and lead

children deeper into the woods. Past the woodland edge is an area for children to build their own lean-to, using smaller logs that are scattered around on the woodland floor. A trail skirts the woodland play area, providing access from the end of the parking lot, and benches are positioned so that visitors can look out from under the trees’ canopy towards the river.

Loading/ A’ Unloading Zone for Boat Launch

A Riverfront Seating

This is part of a student project and not for construction.

The Woodland in the northwest corner of the site,

Woodland Play Area

Log Tunnel

h

at

P n’s re

ild

Ch

Sumac Grove

Boat Launch Trail

River

Bike Trail

Riverfront Seating

Woodland Play Area

A large log with a hole cut through it creates a magical entrance to the woodland for children on the children’s path. (For details see Sheet 18.)

Back Up For Boat Launch A'

A Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

A woodland play area includes a build-your-own lean-to structure, logs for climbing, and circles of logs for children to play on, balance on, and sit on perhaps to tell one another stories. (For details see Sheet 18.)

Ashuelot Greenspace Landscape Plan Keene, NH

Design Details: The Woodland

12

the regraded site. It is simultaneously the center of the stormwater filtration system on the site and a central area for play. All water coming off parking lots is filtered and infiltrated as it passes through a meadow, a rocky, gravelly swale, and then finally a small wetland. In large storm events, any water that cannot be infiltrated overflows into the existing stormdrain. On the north side of the swale, a narrow children’s path dips down through the meadow towards the swale, and on the south side,

This is part of a student project and not for construction.

The Rocky Range at the center of the site, is also the lowest area of

a lawn leads up to the pavilion seating area, where parents can watch while their children play. Boulders of different sizes and placed irregularly provide opportunity to improve their coordination, climbing and balancing. At the end of the swale, a mound rises up, and when children scramble over the top, they are greeted with the view of two smaller mounds with concrete culvert tunnels, providing them with a shady place to crawl into. These tunnels are also a feature visible from the Arboretum.

A’

B’

n’s P a

B

A Dry Creek

Mound with stone bench seating

Mounds and tunnels

nd le a a Sw d ky Fiel Roculder Bo

Wetland

Chi

ldre

dge

Bri

th

Different size rocks and boulders create a climbing and scrambling challenge for children as well as a warm sunny micro-climate that will hold its heat after the sun sets. (For details see Sheet 18.)

Children can climb through or scramble over small mounds with concrete culverts buried in them. (For details see Sheet 18.)

6" Inverted Overflow Pipe

Existing Catch Basin Lawn

Rocky Swale

A

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Meadow A’

Lawn

2.5% slope

2% slope minimum Wetland Area

Rocky Swale

B

Ashuelot Greenspace Landscape Plan Keene, NH

B’

Design Details: The Rocky Range

13

100-year flood line

Area for Residential Development

There has been interest in building a residential development on the property in order to help keep “eyes on the park, keep the site on the tax rolls and generate revenue for the building of the park. The alternative design to the left integrates a residential development into the park. The development is placed in the northeast corner of the site, the only area outside of the floodzone (for more information see sheet 6). Other than the pavilion, the large parking area, and the solar panels, all the elements of the final, preferred design are included. A shed with rentable spaces to store canoes and kayaks is added as a way to raise revenue for the maintenance of the park.

Alternative 2

Parking for Visitors and Boaters

Kayak and Canoe Storage Shed

0

0

30'

60'

A second alternative includes both the market and the development, but parking would have to be provided off-site, in one of the many large commercial parking lots nearby.

120'

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

120'

Ashuelot Greenspace Landscape Plan Keene, NH

Alternative: Residential Development

14

This is part of a student project and not for construction.

Alternative 1

DePu (groundcover) PaVi PoDe

PoDe

BePo

TaBa Mow Fescue No Mow/Low rced Turf Mix for Reinfo JuVi PaVi PaVi JuVi

AcRu AcRu CaPe (groundcover)

HaVe

PoTr HaVe

PoTr

MyPe

PaVi

MyPe

RhTy

AmxGr

Meadow Mix

PaVi

PaVi BePo

PaVi

Rain Garden Mix

AcRu

Lawn

PoTr

BePo

PaVi

AcRu

Sedum Mix for Green Roof

BePo

AmxGr

CoSe PoTr

PoTr RoRu

CaxAu PaVi

MiSi PeAt

PoDe

CoSe Rain Garden Mix

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

PoTr BePo

MyPe

Ashuelot Greenspace Landscape Plan Keene, NH

AcRu

Scientific Name

Common Name

Acer rubrum Populus deltoides Populus tremuloides Betula populifolia Salix babylonica Hamamelis vernalis Amelanchier x grandiflora

MyPe JuVi RoRu CoSe TaBa RhTy PaVi MiSi AgPe PeAt CaPe CaxAu

Myrica pensylvanica Juniperus virginiana Rosa rugosa Cornus sericea Taxus baccata Rhus typhina Panicum virgatum Miscanthus sinensis Agrostis perennans Perovskia atriplicifolia Carex pensylvanica Calamagrostis x acutiflora

DePu

Dennstaedtia punctilobula

Red Maple Cottonwood Quaking Aspen Gray Birch Weeping Willow Spring Witch Hazel Serviceberry “Autumn Brilliance” Bayberry Gray Owl Juniper Rugosa Rose Red Twig Dogwood Yew Staghorn Sumac Switchgrass Japanese Silver Grass Autumn Bentgrass Russian Sage Pennsylvania Sedge Feather-reed grass “Karl Foerster” Hayscent Fern

*See Appendix E for Meadow Mix and Rain Garden Mix

SaBa AcRu PaVi

Code in Plan AcRu PoDe PoTr BePo SaBa HaVe AmxGr

This is part of a student project and not for construction.

The planting plan favors native plants and uses tall grasses to frame views, easy to manage shrubs to screen parking areas, and colorful vegetation to create out-of-season visual interest.

CaPe

Russian sage, red twig dogwood and switchgrass frame the entrance to the park.

Existing Vegetation: • The line of white pines along the eastern side of the site is removed and undercover is cleared.

• Trees to the north are preserved as much as possible to maintain a buffer between the Ashuelot Greenspace and the houses along Ashuelot Court. Undercover and shrubs are selectively cleared and trees must be trimmed to ensure solar panels are not shaded.

• Trees in the northeast corner are selectively cleared (leaving the most well-established and attractive). Groundcover is cleared to open up views up the river.

• The well-established maples along the western edge of the site are preserved. Groundcover is selectively cleared to provide views in and out of the Greenspace from the Arboretum.

• Trees and shrubs along the southern edge of the site are selectively cleared.

Construction Details: Planting Plan

15

See Sheet 17 for swale details

This is part of a student project and not for construction.

Grading will bring visual interest to the site and help manage stormwater.

An inverted pipe serves as a backup to more quickly drain this depressed area when there are major storm events.

Typically the soils should allow stormwater to percolate directly into the soil Notes: • •

• • This rain garden has an inverted pipe to drain large storm events, which are directed into the culverted stream below. (See Sheet 17 for swale details)

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Because the site is in the floodzone, FEMA regulations must be abided by during construction, meaning that any fill will need to be balance by AT LEAST an equal amount of cut.

Removing the asphalt from the site will decrease the grade of the site by 2" across the site, for a total of approximately 22,000 sq feet of cut. However, it may be necessary to use this space to bring in organic matter and start building soils. (For more information see Sheet 8.)

In addition, in order to bring in topsoil (see Sheet 8 for more information) an additional 6"-1' of fill may have to be removed from the site.

As much as possible, the site is graded as to stay above the seasonally high water table (to avoid standing water on site, for safety purposes) which is predicted to come up as high as 472.5 on the western side of the site.

During and after construction, the site should be observed to see if more fill could be removed, to create more flood storage capacity, and more gravel added to keep children out of the groundwater table. This is another reason why phasing the construction could be beneficial, to allow time for observation (for more information on Phasing, see Sheet 19, for more information on the water table, see Sheet 6 and Appendix C.)

Construction Details: Grading Plan

16

1

Reinforced Turf

Gravel Parking

5

Fill turf-grids with topsoil, mix with lime, fertilizer, and top with seed as specified (see Appendix C) 1-2" Sand bed (may be able to use materials from onsite) 4" Aggregate bed (may be able to use material on-site)

2

Rain Gardens and Swales

Note: Reinforced turf can also be made by adding 1" of clean topsoil over the gravel parking lot (see detail 2) and seeding with a low/no mow mix.

4”-6” Dense Graded Aggregate Surface Course

Rain Garden

6” Aggregate Base (may be able to use existing fill)

2" Fine Pea Gravel (3/8"-3/4" Diameter. Stone) 8" Aggregate Base (3/4" Diameter Stone) Non-woven geotextile (optional) 6" Aggregate Sub-base (may be able to use existing fill)

4 4” Dense Graded Aggregate Surface Course 8” Aggregate Base (may be able to use materials onsite) Fabric Separator

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

1'

Non-woven geotextile

NTS

6

3

Gravel Paths

Along the drip edge of the pavilion

Reinforcing fabric (optional)

6” Aggregated Sub-base (may be able to use existing fill)

Pea Gravel Path (Children’s Path)

3/4" gravel

Gravel Swale

Inverted pipe overflows into existing culvert-ed stormwater channel

On the southern edge of the pavilion parking lot

1'

NTS

Plant with Rain Garden Mix (see Appendix E)

7 Dry Creek

6" 1'

4-6" pond stones

From the pavilion down to the rocky swale

NTS

3'

8

Rocky Swale

Different sized boulders and rocks for climbing, partially buried (at least 1/3 - 1/2 underground) for stability

4-6" pond stones and 1.5" gravel

In the center of the site.

NTS

Non-woven geotextile to keep weeds down

Construction Details: Hardscape and Swales

17

This is part of a student project and not for construction.

Trail and Parking Surfaces

Willow Arch

1. Mark out two trenches, dig to a depth of 1’ and mix with compost.

2. Insert two live willow poles opposite each other along the length of the trenches at a spacing of approximately 8”.

3. Bend each pair of poles together to form an arch and twist or tie together at the top of the arch 4. To increase stability, weave poles horizontally 2’ apart along the tunnel sides

Could be constructed by volunteers

5. In order to build up the growth on the sides of the tunnel, insert poles at an angle of approximately 45 degrees (both directions if more growth is desired) at the base of each upright on each side, these can be pushed into the compost and then woven back the tunnel and twisted in near the top of the curve.

Play Feature

Human Sundial

Take a large log, at least 4’ in diameter, and cut a tunnel through with a chainsaw.

This is a heavy element and will need to be placed early on in the construction as it may require heavy machinery to get on-site.

This is part of a student project and not for construction.

Construction Information

Play Feature

Construction Information

Pavers, either painted or carved with the months of the year and hours of the day, are placed in gravel. When the visitor stands on the paver that corresponds to the current month their shadow with fall on the correct time of day.

Place different sized rocks and boulders (no higher than 3', for liability purposes) to create a rocky playscape and fill with 1.5" gravel. All boulders should be at least 1/2 - 1/3 underground.

This may be a difficult item to find. A tunnel could be created out of smaller logs, if this design proves to be too expensive.

Boulder Play Area

Log Tunnel Using 4-6” diameter black locust logs (stripped of their bark) construct two upsidedown Vs in order to support a central log. Bolt logs together (make sure bolts are sunken) and bolt several other logs to begin to form the shape of the lean-to. Leave other stripped black locust logs around to allow children to construct their own structure.

Build-Your-Own Lean To

Young Child Play Area with Hand Pump Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Could be constructed by volunteers

3’ Fill

Place 10' sections of 3' diameter culvert on the ground and back-fill around it to stabilize. Cover in soil and plant.

Mounds and Tunnels

Bury black locust logs of varying heights (approx. 3’-6’) at least 3' deep to create a “maze”. Check for structural integrity regularly and reset as needed.

Have a 2” diameter agricultural well dug* (not for potable water) and connect to a hand pump. Place small log discs and flat rocks around the pump to give small children different elevations and objects to climb on. A gravel swale or small stone runnel should be built to connect the runoff to the dry creek.

Could be constructed by volunteers

3-4' deep

Log Maze Ashuelot Greenspace Landscape Plan Keene, NH

Construction Details: Play Features

18

Phase 1

Phase 2

Asphalt should be removed from site as soon as possible.

This will accomplish several things: A. Allow the site to be observed, to see areas that are poorly draining due to clay subsoils (see Appendix C for more information on soils) B. Provide 2”-3” of “cut” that can be used to bring in organic matter to build soils (remembering that FEMA regulations stipulate that all fill added in floodzones must have corresponding cut to preserve flood storage capacity) Asphalt can be ground and stored on site (out of the floodzone) and used later for trail and parking surfaces if desired.

Phase 4

Phase 3

If possible, this may be an ideal time to do any grading and/or hardscaping on site (such as paths, and parking lots).This will establish the drainage system on-site, so that proposed drainage can be observed and evaluated and allow for soil to start being established and remain undisturbed.

To save money in creating the parking lot, existing asphalt could be resurfaced instead of bringing in gravel. Asphalt may also be recycled for parking surfaces and/or trails.

During this stage there may be an opportunity to create some usable spaces on site, such as establishing a space for the farmers’ market.

Phasing of the Farmer’s Market

Once the asphalt has been removed, the site will need to be managed to make sure that undesirable plants don’t establish themselves. This could be accomplished in several ways, while also building soil.

A. 2-3” of compost could be brought in and tilled into the top layer of fill, a frost-kill cover crop, such as oats, could be planted in the Fall in order to further enrich the soil.

B. A composting program could be started on site, managed by a local composting company.

C. The town Public Works Department could bring leaves and wood chips (chips could also be used from the downed white pine trees on the eastern side of the site) and start a soil building program on site.

D. A longer term option could be seeding a meadow mix, such as Ernst’s Native Biomass Mix for Strip Mines which is designed for heavily degraded sites. If this mix were allowed to cover the site for 5 years or more, biomass would be greatly increased. Succession could then be managed in order to create wooded areas, such as the woodland play area in the northwest corner.

The preferred plan is designed to facilitate a phased Farmer’s Market. The gravel pad that the pavilion will eventually sit on could be put in, and then vendors could bring tents and set them up much as they do at their current site. The grading of the site directs stormwater off this exposed gravel surface into the swale and then the dry creek bed that leads to the rocky swale and wetland in the middle of the site. Once the City is ready to build a pavilion, the gravel pad would make construction easy without disturbing the establishment of the rest of the site. A solar panel shade structure could shade the area while taking advantage of southern exposure.

Temporary Farmers Market Seating Area

The development of different areas of the park could then be phased in many different ways. During the fundraising effort interest in different park areas (such as the boat launch or the Farmers’ Market) could be gauged in order to determine which areas should be developed first. Play areas and plantings could be put in by volunteers whenever possible. A tolerant meadow mix or cover crops could keep the site looking green and attractive while also building soils and demonstrating how to reconstruct a degraded site. The agricultural well, dug to supply the children’s hand-pump, could be used to water the site until plants are established.

Instant Park If faster results are desired, it would be possible to finish the construction in one season (spring - fall). Most likely this would mean carting away fill and bringing in topsoil. The meadow would still take 3 or so years to establish, during which time it would need to be fenced off, and plants would require a lot of watering in order to get established.

This is an attractive option because it requires the least long term management, however, it’s downsides include: • Removing fill and bringing in topsoil is expensive.

• Topsoil must be stripped from another site, and it is unclear what weed seeds it may contain.

• It may be hard to get plants established, they will have to be watered heavily (this will be true regardless).

• Instant park wouldn’t allow for as much community involvement, although after an initial construction push, volunteers could help build play areas and do plantings.

Next Steps •

arket

M Pop-Up

•

r the Access fo farmers

A conversation with the State and FEMA is encouraged to determine if some of the floodplain regulations could be waived because of the restorative nature of the project.

Review this plan with the Conservation Commission, to make sure all regulations are being met.

Permanent Farmers Market with a pavilion that has both a green roof (north side) and solar panels (south side) Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Implementation & Phasing

19

This is part of a student project and not for construction.

Phasing the Development and Revegetation of the Site

This is part of a student project and not for construction.

Ashuelot Greenspace

Wildflower Meadow Mix

West Street

Existing areas of turf along Ashuelot Street are replanted to create an inviting entrance from West Street, connecting the park to Keene’s downtown and guiding residents towards the Greenspace and the Farmers Market.

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

A Glimpse into the Future

22

This is part of a student project and not for construction.

An interpretive sign at the entrance of the greenspace could introduce visitors to the site’s history, different elements of the new greenspace, and to the ecology of the Ashuelot River.

Ashuelot Greenspace History of the Site: The site was originally, most likely, floodplain forest, like the forests up-river.

Floodplains are a changing landscape, they are meant to flood periodically to replenish nutrients. Floodplains improve water quality, erosion control, and act as a buffer against catastrophic flooding. Oxbows, curves in the river that were cut off by large storm or flooding events, can be found along the Ashuelot River.

1774 Mill Pond and Dam constructed for mill power. The site shared a border with the mill pond. When the millpond was filled in, the site was diked and drained in order to create agricultural fields and then, later, an overflow parking lot for the Colony Mill Mall.

In 2013, three locals bought the site with a plan to make it into a vibrant community greenspace. Today, the site is designed to: encourage natural play, educate visitors about the beautiful Ashuelot River, create a place for relaxation and recreation and clean and filter stormwater.

Discovery Path:

Magestic Blue Herons can be seen up and down the river.

The Ashuelot River in Keene is home to a large population of the endangered dwarf wedge mussel.

Oxbow

Water, Plants, Stone and Sun

In the greenspace, Low Impact Development strategies, such as those shown below, slow, channel, infiltrate, evaporate, and clean stormwater through gravel and vegetation, reducing the burden on underground stormwater systems and ensuring water is treated before entering into the Ashuelot River.

Rain and Runoff Green Roof: vegetation captures rainwater and creates a thermal layer for passive cooling

Taking advantge of the site’s sunny southern exposure, solar panels provide energy for the park, and the city.

Rocky swale

YOU ARE HERE

Dry creek Raingarden

Children follow the pea-gravel trail to discover different natural play elements.

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

The word is of Pennacook or Natick origin.

An experiment in sustainable park design and gateway to the Ashuelot river.

The Ashuelot River is the remnant of Glacial Lake Ashuelot. 12,000 years ago, the lake breached at its southern border and flowed into greater Lake Hitchcock, joining the Ashuelot River to the Connecticut River. Native soils underneath the Ashuelot Greenspace are full of pockets of clay, rememnants from when Keene was at the bottom of this glacial lake.

THE SITE

Ashuelot: means “place between”

Ashuelot Greenspace Landscape Plan Keene, NH

Gravel parking and paths

Reinforced turf

Beavers make their homes along the river. Look for their lodges, which appear to be piles of sticks and brush.

We need your help!

If you’re interested in becoming a friend of the park, contact the Keene Parks and Recreation Department.

Appendix A. Interpretive Sign

23

by providing an access flood storage area in the park and mimics the nearby floodplain ecosystem. The design incorporates a trail system for children using different textures, height of plants, tunnels etc. and a beaver-lodge-inspired wooden playscape structure. The plan includes 20 parking spaces. The culverted stream is daylighted into the wetland.

The Grasslands main design theme is maintaining the feeling of a wide open space. Various meadow

This is part of a student project and not for construction.

The Restored Wetland design concept mitigates potential flooding for the five duplex housing development

grasses frame an innovative playscape, and a tree lined pop-up market. The path through the park connects to Ashuelot Street on the northeast and southeast corners of the park. The culverted stream is daylighted in the wet meadow. This design includes 50 parking spots.

100-year flood line Beaver play lodge

playground Development

A’

B’ A Ashuelot Street

Boulder play area

A’

farmers’ marke

reinforced turf

Parking

t

Flood storage capacity

A-A’

Play Parki n

g

A-A’

Ashuelot Street

Childrens adventure trails

parking

A

B

Park

Farme

Housing Development

Floodable restored wetland

flood storage capacity development park play

PROS • Wetland is restored with constructed pools.

• Large flood storage capacity.

• Play is integrated into the entire park and wetlands

CONS • Housing development in a floodplain • No farmers market • Limited passive recreation • Views across the park are blocked

parking Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

rs’ Ma rket

B-B’

PROS • Sense of open space • Brings sidewalk into site • Creates new meadow habitat • Some parking off-site • Convenient access for vendors • Contemplative areas • Lateral Views

CONS • Requires re-grading • Unclear how market are will be used off hours • Establishing meadows can be difficult and take time.

Appendix B : Initial Conceptual Alternatives

24

and creating bridges on the northern and southern western border of the site to allow the area to seasonally flood. This area is filled with boulders and other natural play features. A covered permanent farmers market pavilion serves as a flex space for community events. The design includes 50 parking spots. The culverted stream is untouched.

This is part of a student project and not for construction.

Oxbow Park is a grand gesture in floodplain ecology. The river is extended into the site by digging through the dike

Stormwater Park cleans water from the existing stormwater channel culverted beneath the site and

daylights it as an emergent spring, a wandering brook, a wading pond and eventually returning into the stormwater culvert. This system also treats all stormwater on site. This design sets aside a space for a small development lot, 50 spaces for parking, and a permanent farmers’ market structure with a courtyard.

tree house

farmers’ market

wading pool play area

parking spring Ashuelot Street

bridges

market

parking

play park

farm markeerts

flood storage

PROS • Covered permanent market • Flex space can be used for naturebased childcare or community events

parking

CONS • Potentially expensive • Requires building an outlet through the arboretum and breaking through dike (probably illegal) • Southern side dominated by parking • Views across the park are blocked • Market and events are close to residential neighborhood.

PROS • Covered pavilion can be used for community events development flood • Demonstration of wetland systems storage • Water features create area for sound and play play parking • Small building lots keep property on tax park rolls farmers’ • Separated play area for 1-3 yr olds market • Mound seating gives river views

Rainfall

Culvert play area Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

farmers’ market Ashuelot Greenspace Landscape Plan Keene, NH

Run-off

Sandbox

CONS • Potentially expensive • Least flood storage capacity • Requires filtration system • Specialized maintenance • Views across the park are blocked

Wading Pool

Stream

Filtration System

Emergent Spring

Wetland

Stormwater Channel

Appendix B: Initial Conceptual Alternatives

25

This is part of a student project and not for construction.

Results and locations of four soil pits dug on June 3, 2014

Pit 3 Pit 2 Pit 1 Pit 4

Signs of groundwater table as high as 1.5' below surface.

Signs of groundwater table 3' below the surface

Signs of a perched water table right below the surface.

Signs of groundwater table 3.2’ below surface.

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Appendix C: Soil Pits

26

This is part of a student project and not for construction.

Plan for 1983 Construction of Parking Lot. From the Keene Planning Dept.

Notice pre-parking lot topography lines.

475

472

476

474

473 471

474

Existing Contours Contours pre-1983

470

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

478

Appendix D: Parking Lot Construction

27

Rain Garden Mix Schizachyrium scoparium Chasmanthium latifolium Elymus riparius Echinacea purpurea Carex squarrosa Carex vulpinoidea Liatris spicata Rudbeckia hirta Senna hebecarpa Coreopsis lanceolata Andropogon gerardii Asclepias incarnata Aster novae-angliae Baptisia australis Eupatorium coelestinum Monarda media Tradescantia ohiensis Verbena hastata Zizia aurea Agrostis perennans Solidago juncea

Little Bluestem River Oats Riverbank Wildrye Purple Coneflower Squarrose Sedge Fox Sedge Marsh (Dense) Blazing Star Blackeyed Susan Wild Senna Lanceleaf Coreopsis Big Bluestem Swamp Milkweed New England Aster Blue False Indigo Mistflower Purple Bergamot Ohio Spiderwort Blue Vervain Golden Alexanders Autumn Bentgrass Early Goldenrod

22% 15% 10% 6% 5% 5% 5% 5% 4% 3% 2% 2% 2% 2% 2% 2% 2% 2% 2% 1% 1%

From Ernst Seed Catalog. Mulch after seeding to prevent seed from washing away.

This is part of a student project and not for construction.

This mix of native facultative wetland and upland species provides extended color and biodiversity in a rain garden.

This meadow mix is a colorful selection of native flowers and grasses, designed to be 3'-4' tall and attract pollinator species.

Meadow Mix Schizachyrium scoparium Bouteloua curtipendula Elymus virginicus Sorghastrum nutans Chamaecrista fasciculata Rudbeckia hirta Senna hebecarpa Penstemon digitalis

Little Bluestem Sideoats Grama Virginia Wildrye Indiangrass Partridge Pea Blackeyed Susan Wild Senna Tall White Beardtongue Andropogon gerardii Big Bluestem Asclepias syriaca Common Milkweed Baptisia australis Blue False Indigo Liatris spicata Marsh (Dense) Blazing Star Monarda fistulosa Wild Bergamot Penstemon laevigatus Appalachian Beardtongue Senna marilandica Maryland Senna Solidago nemoralis Gray Goldenrod Tradescantia ohiensis Ohio Spiderwort Ziza aurea Golden Alexanders Aster laevis Smooth Blue Aster Aster novae-angliae New England Aster Aster prenanthoides Zigzag Aster Heliopsis helianthoides Oxeye Sunflower Rudbeckia fulgida var. fulgida Orange Coneflower Silphium trifoliatum Whorled Rosinweed Solidago juncea Early Goldenrod

30% 12% 12% 4% 5% 5% 2% 3% 2% 2% 2% 2% 2% 2% 2% 2% 2% 2% 1% 1% 1% 1% 1% 1% 1%

Adapted from Ernst’s Showy Northeast Native Wildflower & Grass Mix

Michele Carlson & Gallagher Hannan Conway School of Landscape Design * Spring 2014

Ashuelot Greenspace Landscape Plan Keene, NH

Appendix E: Plant Mixes

28