Water: Nonpoint Source Success Stories
New Jersey (Section 319I - 1994)
While agriculture certainly contributes to water quality degradation, intense development has forced New Jersey to turn its attention to both urban and suburban sources of nonpoint pollution. To address this nonpoint source problem, the New Jersey Department of Environmental Protection has shifted its emphasis from structural abatement of runoff from a single development site to a more holistic approach that integrates all phases of site development. This watershed approach considers the natural and human interaction throughout the entire drainage area. New Jersey is also emphasizing prevention because it is cost effective and does not rely on regulations. However, because even well-planned land disturbances increase runoff, New Jersey must still rely on structures that reduce nonpoint source pollution. Wildflower Blooms Buffer Runoff Effects More and more observers are appreciating the beauty and grace of wildflowers, but few have ever considered using a meadow to control water pollution. That is, until New Jersey decided to compare the effectiveness of seeding - detention basins with wildflowers rather than traditional turf grass. This new approach has New Jersey developers and municipalities sitting up and taking notice. Not only does a wildflower meadow produce a diverse habitat for wildlife and an appearance more interesting than that of a manicured golf course, but developers have also discovered that a meadow significantly reduces maintenance costs.
In New Jersey, detention basins are the most commonly used stormwater management structures. Turf grass--which provides a quick, effective way to control erosion and reduce other pollutants--is generally planted early to stabilize the bottom and sides of the basin and provide long-term ground cover.
However, methods used to maintain turf grass--applying fertilizers and pesticides and mowing frequently (as much as 10 times during the growing season)--can negate any benefits gained in water quality and cost effectiveness. Excess soluble pesticides and fertilizers can mix with stormwater runoff and be carried into receiving waters. Excess chemicals can leach into underground aquifers. Finally, frequent mowing and disposing of grass clippings is expensive --even with a reliable volunteer program. New Jersey, aware of the problems of turf grass, was anxious to participate when the Mercer County Soil Conservation District (MCSCD) proposed studying the effectiveness of using wildflower meadows instead. In 1990, the New Jersey Department of Environmental Protection (NJDEP) provided a $8,500 grant through section 319.
The study looked at various wildflower mixtures and application methods and identified environmental factors needed for success. In selecting test sites, MCSCD looked for construction projects that needed to comply with soil erosion and sediment control regulations--and several developers volunteered for the project. MCSCD used various mixes, methods, and rates of seed and fertilizer on 10 detention basins. Site preparation was similar, using mulch and tackifier. MCSCD did not apply herbicides since the study's focus was to avoid nonpoint source - pollution.
For several months, MCSCD collected data daily on numerous elements--weather conditions; soil moisture and temperature; and germination, flowering, and establishment times. The final site evaluations were based on several criteria--percent of wildflower cover, weeds, and total cover; maintenance, including mowing required to suppress weeds; and appearance, considering stand density and height.
Soil moisture proved to be the most important success factor. Moderate moisture produced the best results; low moisture encouraged weeds; and long periods of heavy moisture was detrimental. Given the proper conditions, most seed mixtures were effective, suggesting that any native wildflower seed or mixture adapted to a particular region will thrive with the right conditions and proper maintenance.
Although weeds were a significant problem, mowing twice during the first year as well as other precautions provided effective controls. After the first year, MCSCD recommends mowing in late fall to disperse seeds and prevent woody growth. Also, overseeding perennial species in fall and annuals in spring helps maintain density, promote diversity, and coordinate flowering schedules. These simple, low-maintenance practices are an appealing alternative to using nutrients and pesticides on traditional turf grass ground cover.
The study showed that establishing wildflower meadows may be more expensive--approximately 1 cent per square foot more than traditional turf seeding. However, maintenance costs have proven to be considerably lower--$50 per year per acre for wildflower meadows, as compared to $500 per year per acre to maintain turf.