Kennett Square, Pennsylvania
Size & Type of Project:
1.69 acres, Residential
Former Land Use:
Temperate Broadleaf & Mixed Forests
This 1.69-acre residential property and former dairy farm boasts a drip irrigation septic system that handles sensitive wastewater disposal while preserving hillside woodland vegetation, and green roofs that absorb rainwater and reduce peak stormwater surge while regulating building temperature. Additionally, the site includes a designed stormwater system that uses best management practices to direct and control storm water flow, recharge ground water, reduce peak stormwater surge, and create aesthetic landscape features. The relatively steep slopes on the project site initially posed challenges for water management, as well as the ability to site improvements. However, this became an opportunity to demonstrate creative water management techniques. Improvements including, stone and vegetation lined swales, below grade cisterns, Hugelkultur devices, soil berms, green roofs, holding wet ponds, and rain gardens were worked into the slopes creating terraced rooms and unique garden spaces. In December 2012, after hurricane Sandy, there were no signs of soil erosion on-site for the first time since 1993.
Other unique features of the property include native woodlands and meadows, a potting shed built from salvaged materials, culinary planting beds, a meditation labyrinth, whimsical sculptures, and a straw bale hut.
The property is located along an eastern slope of the mid to lower Piedmont region of Pennsylvania and is characterized by largely wooded, low rolling hills and steeply incised stream valleys. It is a transitional area between the mostly mountainous Appalachians to the west and lower, more level ecoregion of the coastal plain to the east. In the area, elevations range from 200 to 1,000 feet. The Piedmont region is underlain by deeply weathered, deformed metamorphic rocks. The sites' Glenelg and Manor upland soils developed from weathered granite, gneiss and mica schist, and are moderately deep to shallow, and well drained. Terrestrial plant communities typical for the site include Dry Oak Mixed Hardwood Forest, and Little Bluestem, Pennsylvania Sedge Opening, and Side-Oats Gramma Calcareous Grassland. These communities are supported by a warm, humid, and temperate climate receiving on average 45 inches of rain annually.
The site has four primary features that demonstrate the principals of sustainability.
The following codes, zoning, and regulatory requirements influenced design decisions regarding this project:
The Design Team's focus on water and soil management drove the design, construction, and planned maintenance responses for the project. A 100-year rainstorm in December 2012 demonstrated the appropriate and adequate design and placement of all stormwater devices. After hurricane Sandy and for the first time since 1993, there were no signs of soil erosion onsite. In addition to the Design Team, Stakeholders provided significant support with site design, selection of reference plant communities, and most notably development of site's operations and maintenance plan.
The primary management goal for the project site is to create a 55-hour garden, a garden that only requires 55 hours a year to maintain. Inspired by a local and notable horticulturist, Dr. Richard Lighty, the owner intends for nature to maintain the site and restore ecosystem functions to reduce the amount of time needed to manage the upkeep of the garden. Healthy soils will support native vegetative communities and managed stormwater will flow through the site without harm to designated recharge areas. The owner anticipates it will take approximately 3-5 more years to achieve this goal, in part because some improvements are yet to be constructed. However, within 2-years after the removal of dominate invasive and non-native plants, both the Hillside and Pleasure gardens already take less time to maintain, leaving more time for leisure/play in the garden.
At end of a 2-year monitoring period, in June 2014, the owner will draft an article/ summary report on soils, vegetation, and stormwater management performance. Monitoring protocols include:
The owner is committed to using the project site as a model for sustainable landscape practices in her community and region. Meeting the goals set forth at the beginning of the project is necessary to retain professional credibility. Through speaking engagements, educational outreach, and site tours SITES goals will be showcased for review and scrutiny. To be successful and able to compel others to convert to sustainable landscape practices, the project goals will be maintained.
Per the owner's understanding, a municipality in Pennsylvania is adopting a model ordinance that aligns with SITES Benchmarks and Standards. Discussions have occurred in Kennett Township about doing the same. With the right leadership it could possibly result in the adoption of an incentive program for building sustainable landscapes.
The biggest challenge of the redesign was the historic use of the property as a farm, which stripped the site of its native plant communities and topsoil, and left highly eroded and compacted soils. In addition, after the farm stopped operations, much of the equipment and structures were buried on the site and had to be excavated.
These challenges lead to the greatest opportunities including rebuilding soil health, reestablishing native plant communities, and repurposing buried materials on the site. Excavated materials have been transformed into new stonewalls, structural road supports, drainage ways, and creative landscape amenities and follies.
Also, the 8-15% grade of the site posed challenges for stormwater management. This developed into opportunities to demonstrate creative water management techniques to direct, capture, and slow runoff. Improvements were worked into the earth as terraces, creating unique garden spaces.
The main goal of this residential design project was to become a landmark demonstration site and educational resource for sustainable land management practices, including:
As mentioned above, the site was designed to act as a community demonstration and educational resource for sustainable land use practices. Therefore, it became important to consider accessibility to garden areas for visitors of limited mobility and groups of varying sizes. A pathway and signage system was designed for users of all abilities. Visitors can arrive, gather at the sacred grove, hear a brief overview of the project, receive a map, and explore the garden on their own. As interest grows, resources will be developed for additional educational programs.
Since the project began before the SITES Pilot Program was launched, some past decisions needed to be adjusted in the field to align with SITES protocols. Other decisions needed to be qualified or quantified post completion such as the amount of soil moved and repurposed for the new driveway. In addition to the owner, the success of this project should be credited to the contractors, suppliers, stakeholders, and design team for their flexibility, willingness to change in mid-stream, and timely humor.
Working through the SITES process has fostered a greater awareness and knowledge about sustainable development practices. The owner and design team have a better understanding of the process and resources available, and how to implement sustainable strategies in the appropriate sequence. Particularly the importance of determining long-term management needs and costs during the design phase of the process.