Paired Watershed Research
A research study, which relies on event-based monitoring to track water quality, is being conducted by scientists at the DEC in the Cannonsville Watershed to help determine the effectiveness of Whole Farm Planning (WFP) and implementation. The study aims to test the ability of the WFP process to correctly identify significant sources of on-farm pollution, and subsequently recommend and implement cost-effective management practices that substantially reduce pollutant losses from those sources. A paired watershed design is utilized consisting of one dairy farm and one non-agricultural control site close to each other and of similar size, shape, elevation and soils.
The agricultural watershed is 160 ha and consists almost entirely of the farm itself. It is the headwaters of a small tributary that arises on the farm. Land use in the watershed is approximately two-thirds forested; the remaining acreage consists of rotated cropland, permanent hayland and pasture, and the farmstead area. The control site is also a headwater watershed, drains 90 ha, and is composed of forest land, abandoned field returning to forest, and shrub land. There are one permanent residence and several weekend residences in the watershed.
Both sites were monitored for two years (June 1993 – May 1995) prior to any management practice installation on the farm in order to establish an accurate relationship between the hydrologic responses of the agricultural watershed and the control watershed. The farm was then treated with all practices recommended in its Whole Farm Plan. These include a 9-month capacity manure storage, a rotational grazing system, barnyard water management, manure spreading schedules, farm road improvement, milkhouse waste diversion to the manure storage, stream diversion away from the barnyard area, tile drainage, relocation of the silage storage area, and upland diversion installations. Monitoring began again in November 1996 and is continuing for five years. Water quality before and after implementation is being compared to determine to what degree Whole Farm Planning and implementation of practices improved agricultural runoff from the monitored farm. Detailed records of farm activities, such as location and amount of manure spreading, fertilizer used, and so on, are being kept in order to relate changes in water quality to changes in farm practices. A report is anticipated during the summer of 2001 that will summarize the results of the first four years of post BMP implementation.
The results of the first two years of post-implementation sampling indicate a decrease in concentrations loads of dissolved phosphorus leaving the farm. This would be consistent with storage of manure during critical runoff periods in winter and spring. There is also some evidence of reductions in ammonia loads and concentrations. Results of the macroinvertebrate sampling show clear-cut improvements at the farm in the diversity of the stream biota and the prevalence of desirable species.
Project: Paired Watershed Research
Location: Town Brook
Contact: Patricia Bishop
Bureau of Watershed Management
New York State Department of Environmental Conservation
E-mail: [email protected]