Opportunities for Intervention

Current Problems Are Future Opportunities

By applying a watershed stormwater approach and implementing GSI on the Strawbery Banke Campus, both on-site and off-site problems can be addressed holistically to accomplish multiple goals Proposed solutions are proposed to combine a variety of GSI techniques at the seven identified areas of concern. The projects adhere to the goals identified in the Plan and can be completed in any order, as funding becomes available and time permits. Each project looks to address stormwater management, but also improve parking lot efficiency, connectivity throughout the campus, and the overall visitor experience.

The following matrix summarizes the areas of concern, briefly describes the proposed solution, identifies the project goals, suggests a time frame to complete the project and provides a comparison of the estimated costs relative to each other (outlined below).

$ - Low Cost (shared with the City.)

$$ - Medium Cost with low-level improvements.

$$$ - High Cost and includes improvements beyond stormwater. $$$$ - Most Expensive, includes significant campus improvements beyond stormwater.

Additional stormwater improvements can also be included in other campus improvement projects to Reduce, Control, Capture, Store and Overflow. Such projects may include disconnecting building downspouts and roof runoff, addressing grading and drainage within the small satellite parking lots along the perimeter of the campus or additional road repairs using GSI techniques to stabilize the surfaces to reduce erosion and better control stormwater runoff.

A map accompanies the matrix to identify the project location and stormwater toolbox techniques to be applied.

Atkinson & Court Streets Intersection

Eliminate off-site contributing stormwater, reduce erosion and localized campus flooding.

Reduce and control off-site stormwater runoff from Atkinson Street to prevent it from entering Court Street.

1-2 years $

Washington Street Runoff

Eliminate off-site contributing stormwater, reduce erosion and localized campus flooding.

Reduce and control off-campus stormwater runoff on Washington Street to prevent it from entering the campus at the driveway access.

1-2 years $

Main Parking Lot — Layout & Runoff

Manage, control and move water through the campus, re-design campus use areas, incorporate educational components.

Re-design of the parking lot area to increase parking efficiency and capacity, provide better connectivity and wayfinding, and control, capture and store stormwater.

3-5 years $$$$

Internal Pathways and Side Streets (Jefferson & Atkinson Streets & Mast & Horse Lanes)

Manage, control and move water through the campus, reduce erosion along internal roadways and localized flooding, re-design the campus use areas, incorporate educational components.

Create a foundation infiltration basin by diverting surface flow to existing Marshall House foundation.

1-2 years $$

Carpenter’s Shop — Localized Flooding

Reduce localized flooding, manage, control and move water through the campus, re-design the campus use areas.

Create a vegetated wet swale to control, capture, store and overflow stormwater runoff away from the Carpenter’s Shop.

2-3 years $$

Puddle Dock Lawn — Localized Flooding

Reduce localized flooding, manage, control and move water through the campus, re-design the campus use areas, incorporate educational components.

Convert a portion of the existing lawn area to a constructed wetland to control and store stormwater on the campus.

4-5 years $$$

Existing Floodplain, Marcy Street Edge Reduce localized flooding, manage, control and move water through the campus.

Create a controlled overflow from the campus to allow water to leave the campus to reduce impacts of flooding.

4-5 years $

Disconnect Court Street

Area of Concern: Atkinson & Court Streets Intersection

Proposed Solution: Disconnect Court Street to prevent off-campus stormwater runoff

PISCATAQUA RIVER ATKINSON STREET

Design Intent Area Of Concern Before After 1 1

Work with the City to reset the vertical granite curb along Court Street to eliminate the vulnerability. Direct pedestrian traffic to a more visible and properly designated crosswalk. Reduce erosion down Atkinson Street and the total amount of stormwater reaching the central lawn. By resetting the vertical curb, stormwater generated by off-campus impervious areas will be directed towards the existing catch basin found on Court Street. In the event this catch basin clogs from leaf litter or debris, a raised planter is also proposed behind the sidewalk to hold the campus perimeter and isolate the low point surrounding the catch basin.

Shapley House

RAISED PLANTER TO RETAIN PONDING WITHIN ROAD IF CATCH BASIN CLOGS PROVIDE 6” REVEAL RETAIN STORMWATER IN ROAD PUDDLELANE

Pitt Tavern

Disconnect Washington St.

Area of Concern: Washington Street Runoff

Proposed Solution: Disconnect Washington Street to prevent off-campus stormwater runoff

Similar to the conditions found at the Intersection of Atkinson and Court Streets, an existing curb cut at the low point along Washington Street allows stormwater to bypass the existing catch basins and enter the Strawbery Banke campus. When debris (sand, snow or leaf litter) clogs the existing catch basins, or when the outflow pipe is underwater during high tide, stormwater will overtop and enter the campus. Although the contributing drainage area has less impact than the Atkinson and Court Street site, Washington Street provides another opportunity to reduce and control off-site runoff entering the campus.

In order to preserve the existing vehicular access point into the campus center and the historic character of Washington Street, install a mountable, granite curb along to elevate and continue the existing brick sidewalk. The mountable curb maintains vehicular access into the campus while maintaining the existing gutter line and keeping the stormwater within the road.

To make up the difference in elevation on the inside of the new brick sidewalk, a stabilized surface is proposed to gradually slope into the campus to meet the existing grades. The stabilized surface should be designed to provide H-20 loading, which might be accomplished with granite cobblestones or similar materials to match the historic character.

Flush Granite Curb Stabilized Transition

Elevated Brick Sidewalk

MOUNTABLE

Granite Curb

Parking Lot Improvements

Area of Concern: Main Parking Lot - Layout + Runoff

Proposed Solution: “Parking Garden” capacity, better and improved stormwater collection/retention

Area Of Concern

The existing parking lot fails to meet the museum’s growing demands for visitor and bus parking (up to eight school buses.) The existing parking geometry and circulation patterns are inefficient. Beyond lack of capacity and stormwater controls, the parking lot lacks wayfinding and strong pedestrian connections. The museum has also identified a need for improved signage to guide newcomers towards the Lawrence J. Yerdon Visitor Center.

There are several archaeological sites identified by Strawbery Banke Museum under the existing parking area. Below ground, obstructions may impact where trees can and cannot be planted, where excavation beyond 1-foot can and can not occur, and where stormwater conveyance versus storage may be best located. The landscape must also be designed in harmony with the historic context, and not detract from it.

Design options, infiltrating stormwater, and plant selection are limited due to a rising seasonable groundwater table.

Design Intent

The basis of design uses native plants that take advantage of the existing wet conditions while expanding needed parking. The conceptual design illustrated on the previous page expands the parking lot footprint., with drive aisles and bus-slips designed for school bus turning radii. The design offers a total of five bus slips and sufficient space for three more parallel bus parking spots to provide parking capacity for eight buses.

The design also recommends a dedicated bus drop-off area and entrance walkway to improve the sense of arrival at the campus entry. A gentle reconfiguration of the exiting curb cut at the main gate pivots the angle and approach to be more inviting. Safety is further addressed with the addition of solar-powered lampposts to improve visibility at night.

To improve stormwater management, the design integrates GSI techniques at a variety of scales to manage parking lot runoff at the contributing source. Broadbased dips are incorporated to allow unimpeded vehicular movement, while also controlling the conveyance of overland stormwater runoff towards inlet flumes and into vegetated depressions. The design also adds canopy trees to reduce heat island effect, adds to species diversity campus-wide, and softens both visual and runoff impacts of a large, paved surface.

Museum stakeholders expressed a strong desire to better connect the Strawbery Banke Museum campus to adjacent destinations. The design includes improved sidewalks and an elevated boardwalk linking the parking lot to the Lawrence J. Yerdon Visitor’s Center as well as Marcy Street and Prescott Park. Wayfinding and educational signage could be installed across this linear connection to educate visitors about the site’s history, native plants and the climate change. Beyond the physical connection, the boardwalk will also serve as a strong visual connection, enticing Prescott Park visitors and pedestrians along Marcy Street to explore the campus.

The vision of the new parking lot at Strawbery Banke aims to bring an array of benefits beyond its primary parking function. The “parking garden” concept welcomes visitors old and new, controls and captures stormwater, provides habitat for native species, an protects the future by celebrating the past.

PAVED INLET FLUME

SOURCE: HORSLEY WITTEN GROUP

RAIN GARDEN

SOURCE: HORSLEY WITTEN GROUP

BROAD-BASED DIP

SOURCE: INHABITAT; PRATT

MATURE CANOPY TREES

SOURCE: HORSLEY WITTEN GROUP