The Thacher School, located on hundreds of acres in the upper Ventura River Watershed, is committed to stewarding its lands using regenerative practices. With a large, integrated horse program central to campus life, the school partnered with Watershed Progressive and the Ventura County Resource Conservation District (VCRCD) to design and implement projects that reduce nutrient and sediment runoff from livestock areas while serving as a model for forward-thinking land management.

Funded by a grant from the State Water Resources Control Board through the EPA Nonpoint Source Pollution Program, the project combines rainwater harvesting and denitrifying bioreactors to improve downstream water quality. Fourteen 5,000-gallon rainwater tanks were installed at three horse unit locations to capture roof water.  This intervention helps to reduce peak storm flows that transport sediment into waterways. Secondarily, rainwater harvesting offsets potable water use by providing drinking and wash water for horses.

Denitrifying bioreactors were constructed to treat stormwater runoff from uncovered horse boarding areas before it enters the stream system. These systems use woodchips as a carbon source and gravel media to support beneficial bacteria that convert nitrates into harmless nitrogen gas. The bacteria effectively removes unwanted nutrients from the water, protecting aquatic habitat in San Antonio Creek and the broader Ventura River Watershed.

Education and demonstration are integral to the project. Interpretive signage, tours, learning opportunities, and online resources were developed to engage students, faculty, neighbors, land managers, and agencies. Ongoing monitoring is evaluating system performance through stormwater sampling before and after treatment. Samples are tested via laboratory analysis of nutrient constituents and reported to the State Water Resource Control Board. Automated data logging of rainwater tank levels and metered rainwater use are cataloged via a web-based dashboard.