Duckpond Park Upgrade project

This project was initiated during my final semester of classes at UF, in a studio class. The purpose was to redesign a local area with attention to hydrological function and riparian health. I took it a step further, and redesigned for pedestrians, cyclists, stream wildlife, water quality, stormwater control, and plant life. I have since presented this work to the City of Gainesville Bike Ped Advisory Board, and the local Neighborhood Association.

Duckpond Upgrade

Watershed Design Intervention

Jay McLeod

April 2010

Justification for Intervention

Sweetwater Branch is one of Gainesville’s most urban streams, draining 3.3 square miles as it flows from Duckpond Park to Payne’s Prairie. Duckpond Park is located in Duckpond Historic Neighborhood, which is primarily single family residential with some historic buildings scattered throughout. The headwaters of Sweetwater Branch are located underneath a parking lot on Main Street and piped underground to the outfall at the beginning of the park. Historic storm water management practices have primarily used this creek as a drainage feature, although in the park it is flanked by a small amount of public land. There is little to no riparian buffer vegetation along Sweetwater Branch and the creek banks are incised deeply from a “flashy” urban hydrologic regime. Storm water drains directly from neighboring streets into the creek without treatment during rain events. The duck pond itself has steep vertical walls and no littoral area or banks for plants or park-user interaction.

Large amounts of impervious surface in the watershed have led to urban hydrologic drought, stream bank incision, poor water quality, dry riparian soils and reduced ecological function of the creek, making Sweetwater Branch the second most degraded stream in Gainesville. Being the headwaters of Sweetwater Branch makes Duckpond Park an ideal place to implement watershed design strategies to create a more natural ecologically functioning watershed with better water quality and stormwater storage abilities.

Regional Context

Putting the Duckpond Upgrade in a regional context illustrates the opportunities for city-wide pedestrian and cyclist connections, park connectivity, and the diversity of uses in the immediate area. The potential for exercise, recreation, and commuting are optimal due to the multiple nearby bicycle connections and proximity to shopping, business, entertainment, park, and work areas. The extension of the Duckpond Park  bike routes to the 6^th Street Rail-Trail to the west, and the 2^nd Ave Rail-Trail to the south, along with the future connection to the Depot Ave Rail-Trail further south, will create a figure-eight which will facilitate pedestrian and cyclist connectivity.

Duckpond S.W.O.T. Analysis

STRENGTHS

·       Gridiron street network provides high pedestrian connectivity.

·       Existence of active neighborhood association that values Duckpond Park.

·       Location in a historic neighborhood provides interesting context, and public and political concern.

• Headwaters location allows for maximum improvement in downstream water quality.

WEAKNESSES

·       Historic designation may restrict redesign of road system.

·       Watershed is already fully developed and there is no adjacent public open space to incorporate into Duckpond Park.

• Presence of pet walkers on the grass surrounding the creek and fowl in the pond contribute to water pollution.

OPPORTUNITIES

·       Large traffic lanes allow for easy integration of bike lanes.

·       Recent park projects such as Depot Park, the 6th Street Rail-Trail, and Sweetwater Park provide for city-wide connectivity.

·       Degraded stream status and headwater location means large opportunity for water quality improvement.

·       Historic structures and creek support creation of cultural identification projects.

THREATS

·       Primary pollution in this area is non-point source, which is more difficult to diminish and/or remediate.

• Proximity to downtown means potential for higher density redevelopment leading to increased impervious surface and accompanying storm water issues.

Goals of the Intervention

·       Prioritize a pedestrian and bicycle environment conducive to physical exercise, passive recreation, and interaction with nature for multiple user groups.

·       Restore a linear connection for park-goers, wildlife, and the creek.

·       Create a regional connection for pedestrians and cyclists that links to other greenspaces and provides opportunities for alternative commuting.

·       Enhance water quality at this headwaters park, and partially restore pre-development hydrologic regimes through the use of ecological restoration, new technologies, and reduced impervious surface area.

·       Keep the project achievable in the short term by having multiple levels of implementation and using combinations of low-tech and high-tech solutions.

Design Integration

The Duckpond Upgrade can be implemented as an integrated whole, or in separate parts that may have less function than the whole, but still improve upon present conditions. The design can be implemented in several distinct phases:

1. Delineation and addition of bike lanes surrounding the park, an internal, pervious pedestrian walking path, painted crosswalks with speed bumps as appropriate to facilitate pedestrian movement, and the addition of benches, trash cans, doggie-bag stands, and possibly pedestrian-oriented street lamps. The first step in creating a linear park is to make it accessible and useable for people. Strictly delineated areas for pedestrian movement are necessary to facilitate safety and park-usage.
2. Re-grading the riparian zone, planting a riparian buffer and additional tree cover, cooperation from maintenance crews to respect these areas. This will help restore the ecological function of the riparian area surrounding the headwaters of Sweetwater Branch. Re-grading the riparian area with a more gentle, undulating slope to the waters edge will provide better flow conditions during both low and high water conditions. Under high flow conditions, the stream velocity will be slower because the re-grading will provide for a floodplain-style spreading of the stream into a large volume area. Riparian vegetation will slow the water and filter pollutants out. Shade from trees will provide more natural conditions that are generally found in headwater streams, and allow for a more natural assemblage of aquatic organisms (mostly invertebrate shredders), as well as providing tree leaf nutrients more representative of a natural stream.
3. Closing the bridges to automobiles at 6^th, 7^th, and 9^th Avenues and creating nodes of pedestrian interaction, reorganizing the surrounding roads and intersections intersections, and adding bioretention/rain gardens to treat stormwater runoff from the surrounding areas before it enters the creek. The closing of these avenues and subsequent creation of 3 pedestrian nodes of activity (the playground, gazebo, and orchard) represent a fundamental shift in reclaiming the linear Duckpond Park for people. Tearing up the pavement at these bridges, and replanting with native plants or grass would be a significant step toward protecting the creek and the people who enjoy it. Any reorganizing of surrounding roads and intersections must maintain pedestrian and bicycle access, and the bioretention/rain gardens that are created should accept stormwater from the surrounding areas. These rain gardens will be lower than the surrounding areas, and will pond when it rains. They will have underdrain pipes (approx. 4’ under the surface) that will transmit directly to the creek. The rain gardens will treat the stormwater before it enters the creek, and will increase the time of concentration (relative to the existing storm water street drains) which will decrease creek velocity during storm events and maintain a more constant base flow. All storm water street drains in the area should be re-designed so that they drain to a bioretention/rain garden, creating a neighborhood-wide stormwater treatment system.
4. Repaving the road surrounding the Duckpond Park (NE Boulevard) with pervious pavement, plugging all surrounding stormwater street drains, and retrofitting the curbs so that they allow drainage into the riparian soils. The addition of 6” of pervious pavement on NE Blvd (enough to be flush with the current curb) will provide a small amount of stormwater storage because the pervious pavement is approximately 20% void space. Drilling weep holes in the existing curb surrounding the park will allow this ponded stormwater to infiltrate the riparian soils and be denitrified by the bacteria within. In the event that the stormwater overflows, it will be spread levelly as surface sheet flow, passing through the riparian buffer zone. Both of these actions will increase the time of concentration during storm events and help treat the storm water. Since the NE Blvd will now be flush with the internal park, traffic bumps or some kind of minimal-profile automobile separator must now be installed to protect pedestrians and cyclists from automobiles. These cannot interfere with the overland flow of stormwater during rain events.
5. Regional integration of Duckpond Park bike path with the 6^th Street Rail-Trail, the 2^nd Avenue Bike-Trail, and Depot Avenue Rail-Trail. By making NE 5^th Street a one-way street from University Avenue to Duckpond Park, and using the remaining space for a two-way bike lane, we can connect to the south with Sweetwater Park downtown, which will soon connect all the way to Depot Park and the Rail-Trail. By extending the Duckpond Park bike lane westward along NE 10^th Avenue, we can connect with the 6^th Street Rail-Trail, creating a city-wide bicycle commuting opportunity.