Purpose
The goal of this study is to determine if biological uplift and water quality improvement can be achieved by transitioning the zone around traditional stormwater ponds into native meadow habitats. Specifically, the study assesses:
- Pollinator support: Does the addition of native plants increase the diversity and abundance of bees, butterflies, and other beneficial insects?
- Pollutant reduction: Can vegetative buffers improve water quality by reducing nitrogen, phosphorus, and sediment levels in ponds before they enter receiving surface waters?
- Maintenance efficiency: How does "No Mow" management impact long-term county maintenance costs and pollution emissions?
Background
Anne Arundel County manages hundreds of stormwater ponds designed to control flooding, process nutrients, and trap sediment. Traditionally, these ponds are planted with turf grass and mowed frequently, down to the water’s edge. While functional for drainage, turf grass offers minimal ecological value and requires constant upkeep, and can be prone to erosion.
Native Maryland wildflowers and grasses - such as Common Milkweed (Asclepias syriaca) Milkweed) and Little Bluestem (Schizachyrium scoparium) - have root systems that grow several feet deep. Unlike shallow turf grass, these roots:
- Create macropores: Channels in the soil that increase infiltration.
- Sequester carbon: Storing more atmospheric carbon than mowed grass.
- Filter and uptake pollutants: Naturally processing urban runoff more effectively than standard turf grass.
The “No Mow” study was originally conceived as a strategy to reduce bacteria inputs to stormwater ponds by deterring Canada goose congregation (existing research has shown that buffers are an effective method of passive goose control). Further literature review revealed the potential of buffers to reduce inputs of other pollutants, prevent slope erosion, and result in an “ecological uplift” within the pond.
If this study shows that vegetative buffers effectively reduce N, P, and TSS concentrations in pond waters and result in ecological uplift (as measured by species diversity), it could result in buffers becoming standard practice at County stormwater ponds.
Sampling Protocol
Fourteen ponds - seven experimental and seven control - throughout the County were selected for this study. The ponds are visited bi-weekly (once every two weeks), and water samples are taken for N,P, and TSS analysis. During each visit, a water quality sonde is also used to obtain temperature, pH, dissolved oxygen, and specific conductivity measurements. In addition, the number of Canada geese and other waterfowl present within the pond enclosure are recorded during each visit.
Pre-implementation monitoring was conducted for 24 months beginning in April 2024 and ending in March 2026. In Spring 2026, vegetative buffers consisting of native grasses, forbs, and wildflowers, were installed at the seven experimental ponds. These buffer areas will only be mowed once or twice a year. The seven control ponds received no buffer and maintenance will continue as usual. After one growing season, water quality monitoring will continue at all 14 ponds for another 24 months. eDNA samples - used to identify animal species using the ponds - are also collected in April, July, and October at the seven experimental ponds, plus one control pond.
Contact Us
If you have questions about a specific pond in your neighborhood or want to learn more about the research methodology, please reach out.
- Project Lead: Mr. Douglas Griffith, Planner II
- Email: pwgrif04@aacounty.org
- Phone: (410) 222-1071
- Office: Anne Arundel County Department of Public Works Bureau of Watershed Protection & Restoration