A Low Impact Development Demonstration Project: Falls Hill and Poplar Heights
The Conservation District, in partnership with Fairfax County and other key organizations, piloted a groundbreaking low impact development (LID) demonstration project in the Falls Hill and Poplar Heights neighborhoods in 2008 and 2009.
Falls Hill and Poplar Heights: In the Beginning
The Falls Hill and Poplar Heights neighborhoods, bounded by Route 66 and Leesburg Pike (Route 7), have been suffering from drainage issues for years. Developed before stormwater controls were required, their undersized stormwater system was unable to handle the growing rainwater runoff. By the end of the last decade, a significant recurring flooding problem had existed in the neighborhood for ten to fifteen years, particularly in the Venice Street area close to Tripps Run. Due to stormwater runoff from Falls Hill, Tripps Run itself had suffered considerable degradation, and sediment transport downstream had caused damage to infrastructures in the City of Falls Church. In this hilly neighborhood with what once had been a lovely stream, managing rainfall runoff had become a big problem.
Under considerable pressure from local residents and the Providence District supervisor, the Fairfax County Department of Public Works and Environmental Services (DPWES) established a task force that included DPWES Maintenance and Stormwater Management Division and Stormwater Planning Division, the Northern Virginia Soil and Water Conservation District (NVSWCD), the Northern Virginia Regional Park Authority, the Virginia Department of Transportation, Providence District Supervisor Linda Smyth’s office, the City of Falls Church Department of Environmental Works, and representatives and residents from the Falls Hill and Poplar Heights homeowner’s associations.
The group, which called itself the Stormwater Action Committee, met over the course of nearly eighteen months to review the problem and develop options to manage flooding problems. The collaborative process was mediated by Resolve, a consensus-building group. The Northern Virginia Soil and Water Conservation District was actively involved in preparing the final recommendations, one of which was to encourage residents to implement LID practices on their individual lots to reduce runoff volume and peak discharge. To encourage residents to do so, an LID demonstration project was proposed by the Providence District supervisor.
The NVSWCD was approached by the Fairfax County Department of Public Works and Environmental Services to take a leadership role in the funding, design, construction and outreach program for the demonstration project.
Implementing the Project
The Northern Virginia Soil & Water Conservation District wrote and submitted the grant proposal with the support of the other project partners, designed the demonstration project LID practices. Together with the Fairfax County DPWES Stormwater Planning Division, they also supervised the construction work of the LIDs, coordinated the outreach effort (including workshops and the development of a new LID handbook for homeowners), gave additional technical assistance to homeowners, and organized the matching grant program.
County Supervisor Linda Smyth asked for the initial study and stayed informed and involved as the demonstration project was carried out.
Fairfax County DPWES, Stormwater Planning Division, helped with valuable input on the design and construction of the demonstration project, as well as with some of the materials for the construction. DPWES also helped teach and develop the workshops and covered the cost of printing the handbook.
Northern Virginia Regional Commission partnered on the outreach component of the project, particularly the writing of the handbook and the creation of the outreach action plan.
Angler Environmental built the LID plan and helped with the project construction costs.
Jeanne and Victor Klingelhofer allowed the demonstration project to be built on their property, accepted its maintenance responsibility, and graciously allowed visitors to visit the demonstration project.
With an agreement in place about the way forward, the first step was to build a strong partnership.The Chesapeake Bay Restoration Fund (from Chesapeake Bay license plate sales) awarded a grant for $12,000. Of the funding, $9,500 went to the demonstration project, and $2,500 was used for a matching grant program to install additional LIDs in the neighborhood.
The Residential LID Demonstration Project
The Klingelhofer property on Pinecastle Road was chosen to host the demonstration project for a number of reasons. The problems it faced were typical of those in the community: yard erosion, runoff from adjacent yards, difficulty sustaining vegetation or lawn, basement flooding, and stormwater flow continuing downslope to the adjacent lot and to the curb inlet. Also, during the stormwater collaborative process, the property was identified as having suitable soil for infiltration practices. Finally, not only were the Klingelhofers well informed, having participated in the stormwater action committee, but they also were willing to match with some personal funds.
In the fall of 2008, NVSWCD hired Angler Environmental to help install the series of LID practices to demonstrate innovative ways to control stormwater. This included a compost blanket with two terraces backfilled with compost and planted with native grasses, trees and shrubs; two rain barrels in the backyard; a rain garden in the front yard; and a modified French drain in the side yard leading to the rain garden and an infiltration trench in the backyard. The two rain barrels and a catch basin installed in the backyard were all connected to the infiltration trench. A sump pump outlet pipe was diverted to discharge into the rain garden. The LID practices were designed to capture the first one inch of any storm event or 631 cubic feet of runoff, which included runoff from two neighboring lots and Klingelhofer’s own property.
Outreach: Workshops, Handbook, and Field Day
There were two workshops held in fall 2008 to introduce stormwater issues, review the demonstration project case study in detail, and profile six residential LID practices that at the time were listed in the Fairfax County Public Facilities Manual. Participation qualified the attendees for a site visit and technical assistance by staff from the NVSWCD and gave them the opportunity to apply for the matching grants. All participants were given a copy of the Residential LID Handbook and Resource Guide, which built on the workshop content, going into more depth on how to select a practice for a problem, a maintenance guide, rain garden plant list, catalogue of local resources, and a run-down of the six LID practices described in the workshop. These include:
- Rain barrels and cisterns,
- Landscaping and reforestation,
- Dry wells, infiltration trenches, french drains and other filtering practices,
- Rain gardens,
- Pervious pavement,
- Green roofs.
In addition to the workshops, a demonstration project field day was also held in the fall after construction was complete, which would be the first of many tours of the site. The tours were led by the project team and incorporated “how to” opportunities and lessons learned. The site was also used to educate other professionals, host numerous informal tours for neighbors and other community members, and was a site on the Conservation District’s biannual watershed-friendly garden tour in the spring of 2009.
Technical Assistance & Matching Grant Program
Those who attended the workshops were eligible to receive two hours of technical assistance from NVSWCD staff and to apply for matching mini-grants through the funding from the Chesapeake Bay Restoration Fund grant. Several homeowners requested site visits and pursued the sustainable stormwater recommendations that were made. In the case of two neighbors who suffered from shared drainage and erosion problems, the district brought them together, explained the problem and the source, provided options to solve the problem and prepared the design and approximate costs.
Matching grants, accompanied by an additional eight hours of technical assistance, were awarded to help several residents implement their projects. Five grants of up to $500 each were awarded to residents and were accounted for through a reimbursement program. One of the grants went to the local elementary school. Projects included tree and native vegetation planting, compost terraces and coir fiber logs (biologs), infiltration trenches, rain barrels, and riparian buffer restoration and enhancement.
At the end of the year, 60-70 residents had been trained and given further resources, the demonstration project property was no longer a throughway for runoff and a site of erosion and frequent flooding, and there were six total innovative on-the-ground projects as demonstration sites. With these projects, three barriers that had been identified prior to the project had been overcome: knowledge of options, technical expertise, and financial constraints. Additionally, the handbook and workshop presentations were researched and prepared in a way that allows them to be used in other Northern Virginia communities.