The Olentangy River flows 88 miles from its headwaters in Crawford and Richland County through Marion and Morrow County into the City of Delaware and ending in Franklin County at its confluence with the Scioto River. The Olentangy River has a drainage area of 536 square miles. The portion of the river running through the City of Delaware has been designated a state Scenic River by the Ohio Department of Natural Resources since 1973.
Interactive Olentangy River Watershed Map
Stormwater
Storm water runoff is precipitation that flows or “runs off” the surface of lawns, fields, roofs, roads,
etc. Some surfaces, such as roofs, driveways, parking lots, streets, and compact soils are very hard surfaces that prevent any water from soaking into the ground.
The following is the City’s updated Stormwater Management Plan. This document will be updated every five years when our stormwater permit is renewed. If you have comments on this plan please send them to Watershed & Sustainability Coordinator, Lisa Roberts, lroberts@delawareohio.net to be incorporated into the plan.
Rain Barrel Program
The City of Delaware Public Utilities offers discounted rain barrels year-round to residents, in coordination with its Small Municipal Storm Sewer System (MS4) Permit with the Ohio EPA. The barrels vary in color and size based on what is in stock. To purchase a barrel, please contact lroberts@delawareohio.net.
Click here for:
Rain Barrels and Their Benefits
Purchase a Discounted Rain Barrel
Rain barrels connect to downspouts and store rainwater for reuse. There are many benefits to them including reducing stormwater runoff, watering gardens, and lowering water bills.
Olentangy River Festival
Olentangy River Festival Flyer 2025
2025 Nomination Form - Conservation Awards
Rain barrels can also be the perfect canvas for works of art. Every June, a rain barrel raffle takes place during the Olentangy River Festival with over a dozen locally painted barrels raffled off. Are you interested in showing off your art skills or have an interest in sponsoring a barrel on behalf of a local painter? Reach out to the Watershed & Sustainability Coordinator, Lisa Roberts, lroberts@delawareohio.net.
Click Rain Barrel Sponsorship Form 2025 for details on how to participate in our rain barrel painting program.
Watch for more information on these on this page, or on the City of Delaware Facebook page.
Bioretention Cells at OWU
Two bio-retention cells installed on the campus of Ohio Wesleyan University, near Branch Rickey Arena, utilize soil, mulch and vegetation to treat runoff from impervious surfaces such as rooftops, sidewalks and roadways.
All species in the gardens are native to Ohio, which minimizes the need for maintenance, watering and pesticides. The plants have a high moisture and pollutant tolerance that will allow for the uptake of nutrients. The flowers were carefully selected by city staff to attract a diversity of wildlife including Monarch butterflies, bees, hummingbirds and other pollinator species. The project was funded through the City’s storm water fund in compliance with with Ohio EPA.
Delaware Run-Olentangy River 9-Element Plan
The City of Delaware recently submitted a grant application for a Nonpoint Source Pollution Implementation Strategy on the Delaware Run-Olentangy River Watershed. This plan, more commonly known as a Nine Element Plan, was approved in June 2021. It is a living document that will continue to be updated with projects that will reduce nonpoint source pollution in the Olentangy River. See the approved plan here
Hidden Valley Golf Course Stream Restoration Project
The Hidden Valley Golf Course Stream Restoration Project restored 1,346 feet of streamflow and created two acres of riparian buffer and 0.5 acres of restored wetlands. This work addressed eroding stream banks and reduced sediment and nutrient levels in the Delaware Run. Construction was completed in 2025.
Read the Project Summary
Read the Project Fact Sheet
H2Ohio
Leverage state dollars for future water quality improvement projects.
The Riverfront District
The Riverfront District has significant opportunity for community-driven redevelopment that improves the built environment, supports economic development and provides needed amenities within the area. Read more here
Adopt-a-Drain
Be a stormwater hero – adopt a drain! Any person can volunteer to do a bi-weekly clean-up of a storm drain of your choosing. Those outside your home or business are a great starting point. Click here to learn more about this partnership between the City and OWU.
Improving Water Quality
