Williamsburg Wetland Project

Wetlands are vital to healthy watersheds and are often referred to as the kidneys of the landscape.  Soil erosion and nutrient runoff threaten streams and lakes across Ohio, including the East Fork Little Miami River (EFLMR) and William H. Harsha Lake.  Excess sediment and nutrients have contributed to problems with Harmful Algal Blooms (HABs), which have been increasing with frequency in recent years at Harsha Lake.  Wetlands (both naturally occurring and constructed) are efficient natural systems that absorb and filter excess sediment and nutrient runoff during storm events.

Project partners at the ribbon cutting, Sept 2023

In 2023, Clermont Soil and Water Conservation District, in partnership with the Clermont County Office of Environmental Quality (OEQ) and the Village of Williamsburg, completed construction of an off-channel wetland along the East Fork Little Miami River (EFLMR) utilizing a 3-acre reservoir that was formerly connected to the Williamsburg low-head dam, which was removed in 2018. The existing reservoir was converted into an attenuating wetland, which takes water from the EFLMR when the river rises. Within the reservoir, water flows along a graded meandering path to an outlet channel. A flap gate at the outlet channel provides a prolonged, controlled release to maximize water residence time within the attenuating wetland. The outflow pipe slowly releases water from the reservoir into a 2,000 ft. meandering treatment channel that provides additional pollutant removal and energy dissipation before water re-enters the EFLMR. The project team and Ohio State University have established five monitoring locations with flow meters and automated samplers to measure and quantify the amount of nitrogen, phosphorus and sediment removed by the (1) wetland complex forebay, (2) reservoir attenuation wetland, (3) meandering treatment wetland, and (4) entire wetland complex. Monitoring began in June 2023.

To learn more, check out this short video on the Williamsburg Wetland Project


U.S. Fish & Wildlife Service

Ohio Department of Natural Resources / H2Ohio Program

Ohio EPA Nonpoint Source Control Program (319 Grant)

Duke Energy Foundation / Powerful Communities Program