A Needed Stream Improvement for a Beloved Community Park!

(Photo above) University of Delaware students lending a hand to increase native plants growing in existing wetlands in New Garden Park. (c) Kelsey Moxey

Parks play an important role in managing water in the community. They offer opportunities to showcase good land use practices by providing an easy, low cost way to engage visitors and illustrate the value of green spaces. This year New Garden Township is leading by example utilizing open space in their Township Park to showcase Best Management Practices (BMPs) such as no mow zones along streams and streamside buffer plantings which can easily be adopted by residents and visitors on private lands, commercial properties, and farmland. Better land management leads to improved water quality and stream habitat. In addition, these practices provide enriched recreational opportunities for trail users and children to view and explore nature.

The low impact, low cost land management strategies being implemented at New Garden Park include: no mow zones, streamside buffers, and wetland enhancement.

No Mow Zones. Even something as simple as not mowing up to a creek can prove beneficial by slowing down water, and filtering and trapping pollutants in storm water runoff. Currently, the streambanks and adjacent wetlands of Lamborn Run are routinely mowed. While this may seem like a responsible thing to do, good intentions are not always justified. Mowed turf has very little root mass to help hold the banks together during heavy flows thereby contributing to stream bank erosion and poor water quality (see picture below). Mowed grass also diminishes stream habitat by providing little to no wildlife value.

 Unstable and eroding stream bank mowed up to the edge of the bank at New Garden Park © LandStudies

Unstable and eroding stream bank mowed up to the edge of the bank at New Garden Park © LandStudies

Streamside Buffer. A buffer is simply an area of land adjacent to a stream or wetland that ‘buffers’ the water from pollutants. A buffer can include wetlands, no mow zones, and trees and shrubs (as seen in photo below). Pollutants such as dirt, bacteria and harmful pathogens such as Cryptosporidium (found in geese droppings and animal waste), and nutrients run off the land during rain events. Buffers act to trap and filter out these pollutants before they reach the creak. Buffers also increase groundwater recharge as deeper plant roots break up the soil and create more pore space for water to fill. Mature buffers also provide shade to cool water to support cold-water fisheries and other stream life, and form a dense mat of roots to help stabilize soil.

Restored streambank with a no mow zone and pocket wetlands enhanced with native species (c) LandStudies

Wetland Enhancement. Buffers and wetlands create more floodwater storage while also improving wildlife and stream habitat. The wetlands at New Garden Park have been routinely mowed for decades. The first step to improving the health and function of these wetlands is to stop mowing. Mowing wet soils leads to compaction making it more difficult for water to infiltrate thereby leaving less capacity for the wetlands to aid in floodwater storage and groundwater recharge. Without sufficient groundwater recharge small streams like Lamborn Run are subject to dry during prolonged drought. Wetlands also provide food, shelter and water for a variety of wildlife.

The wetland enhancement took place this past September. Eighteen volunteers planted 25 flats (or 1800 small native perennials) in the two adjacent wetlands to Lamborn Run. Installing plants native to our region improves the biodiversity of an area by providing food and shelter for a larger variety of native wildlife. Species planted included Blue Flag Iris, Swamp Milkweed (host plant to the Monarch Butterfly), lavender Beebalm, New York Aster, Ironweed and Soft Rush.  These plants were selected for their potential to compete with existing aggressive grasses while also providing wildlife benefits and improved aesthetics for visitors.

A tree and shrub planting will take place late October and should help mark the ‘no mow’ flood zone, followed by a live stake planting next spring. Live stakes are single stems of dormant shrubs that can quickly take root to help hold together eroding streambanks. Later, they mature into large shrubs which help regulate stream temperatures by providing shade to small streams such as Lamborn Run.

Upon completion of these initial strategies, the White Clay Watershed Association and New Garden Township intend to apply for additional grant funding to implement further actions outlined in the New Garden Stream Corridor Improvements Masterplan. This is a long term plan to be implemented in phases as resources become available.

* The Master Plan and Phase 1 planting are funded by $53,000 from the Pennsylvania Department of Environmental Protection Growing Greener Grant Program, $7,000 from the White Clay Wild and Scenic Rivers Program. Smaller contributions were made by New Garden Township and New Garden Growers Market.