The entire Upper Big Walnut Creek Watershed drains to Hoover Reservoir, the largest raw drinking water source for the City of Columbus covering over 3100 acres in water. Hoover Reservoir supplies the public drinking water to 575,000 Columbus residents. The City of Columbus monitors raw drinking water supplies for 88 water quality parameters.

Hoover Reservoir, while generally considered an excellent source of raw water, has been shown to have elevated levels of the herbicide Atrazine.

According to the Ohio Department of Natural Resources, Division of Real Estate and Land Management 1994 data, approximately 72% of the land use within this watershed is agriculture related. Due to the number of acres actively farmed, there are concerns about agricultural non-point source pollution of chemicals, nutrients and sediments. However, this watershed is encountering development pressure since it is located north east of the City of Columbus.

The increase in development will bring additional water quality issues to the watershed and drinking water supply of the Upper Big Walnut Creek. Development may also reduce the ability of acquiring proper buffers adjacent to the Upper Big Walnut Creek and its tributaries as land use changes.

This Conservation Reserve Enhancement Program (CREP) will improve water quality and protect a major raw drinking water source for the City of Columbus by reducing agricultural run-off containing sediment, nutrients and agricultural chemicals, specifically the herbicide atrazine. This will be accomplished through the installation of 3,500 acres of conservation practices including:

• riparian buffers,
• filter strips,
• hardwood tree plantings,
• permanent wildlife habitat,
• wetland restoration and
• perpetual easements.

Landowners will receive 175% of the soil rental rate per acre per year for 15-years for the grass filter strip and wildlife habitat practice. In addition, landowners will receive 200% of the soil rental rate per acre per year for 15-years for riparian buffers, tree planting, and wetland restoration practices. In addition to 15-year conservation practices the acquisition of perpetual conservation easements is a priority of this proposal.

This project is designed to reduce the amount of atrazine that runs off of fields in the watershed. To encourage the best use of buffers, there will also be a one-time local supplemental payment of $60 per acre available to landowners who enroll a minimum average buffer width of 66 feet adjacent to watercourses. This minimum width corresponds to the label directions for atrazine application as a restricted use pesticide because of ground and surface water concerns. This project will fund buffers up to an average maximum width of 200 feet since the watershed is a major raw drinking water supply.