About the Columbus Watershed Management Section

High-quality water supply sources allow us to provide residents with excellent drinking water at a reasonable cost. Our watershed program’s focus is to protect this vital resource. The Department of Public Utilities created a Watershed Management Section to protect our drinking water sources and supply.

The Division of Water works with the Columbus Recreation and Parks Department to protect water quality by jointly managing the reservoirs and adjacent land along Hoover, Griggs, and O’Shaughnessy Reservoirs. These reservoirs supply 85% of the drinking water treated and distributed to 1.2 million water consumers in central Ohio. The Watershed Management Section helps the division fulfill a commitment to maintaining the reservoirs for the primary function of providing quality drinking water, while also providing the community with compatible recreational opportunities.

Reservoir water quality is impacted by how the land is used in the surrounding watershed. Flowing surface water, rainfall, or snowmelt, easily picks up contaminants such as motor oil, fertilizer, and litter. These types of pollutants eventually reach rivers and reservoirs where they can lead to algal blooms or harm wildlife. Everyone can help protect the water supply by avoiding practices that cause pollution to enter storm drains or local waterways. Watershed Management encourages all upstream property owners to protect the tributary streams by maintaining a buffer of natural vegetation around waterways, which can filter out many pollutants and limit shoreline erosion. For more tips and information on ways to prevent water pollution, visit, Keep It Clean.

Columbus Watersheds

Columbus obtains much of its drinking water from the Scioto River, which supplies water to Griggs and O’Shaughnessy reservoirs, and the Upper Big Walnut Creek, which supplies Hoover Reservoir. Columbus manages its reservoirs for water supply, not flood control. Reservoir water levels do vary in response to precipitation and water usage.

View of Hoover Reservoir

Hoover Reservoir

Water Source:

Upper Big Walnut Creek


  • Large, lake-like water body subject to significant water level fluctuation.
  • Boating limited to 10 horsepower (hp)/10 miles per hour (mph) and with boat size limits.
  • Popular water sports include fishing, kayaking, canoeing, paddleboarding, sailing, and powerboating.

O’Shaughnessy and Griggs Reservoirs

Water Source:

Scioto River


  • Narrow river-like channel.
  • Boating limited to 40 mph with boat size limits.
  • Popular water sports include fishing, powerboating, wakeboarding/water skiing, kayaking, canoeing, paddleboarding.
View of Griggs Reservoir

Recreation Limitations: Swimming, tubing, jet skis or personal watercraft are not allowed in any of the Columbus reservoirs or waterways per Columbus City Code. All watercraft must be registered prior to use, except for paddleboards which are exempt from registration requirements. For a full list of park and waterway rules, please visit Columbus City Code Chapters 919 and Chapter 921.

Columbus Watershed Management Section

Watershed staff are active in the protection of the water supply, and the care and maintenance of the city-owned property surrounding the reservoirs. Maintenance personnel ensure the park areas are accessible and service the dams and other water supply infrastructure. Water Protection Specialists, known as Watershed Rangers, address water quality issues, assist and educate reservoir visitors, and secure the reservoir properties. This section also manages the reservoir Land Stewardship Program which seeks to protect the reservoir shorelines while providing eligible adjacent landowners authorization for activities such as private dock installation or invasive plant removal on city-owned property. Adjacent property owners interested in stewardship activities can sign up to participate in this voluntary program. Please note, unauthorized maintenance of city property is strictly prohibited. Many questions regarding the location of property lines, eligibility for boat dock permits and restrictions pertaining to city-owned reservoir property are answered in the Land Stewardship Frequently Asked Questions for current and prospective adjacent landowners. For more information about the Watershed Management program, please call 614-645-1721.