The western edge of Hilliard is within the Big Darby Creek Watershed. Big Darby Creek, located about two miles west of this area, is a state and national scenic river and one of the most biologically diverse ecosystems in the Midwest.
The Big Darby is home to more than 100 fish and 44 mussel species, including 38 species that are listed as endangered or rare.
The Darby Creek watershed covers an area of 555 square miles with approximately 6.7 square miles of the watershed in Hilliard.
In 2023, the City of Hilliard adopted an updated comprehensive plan that establishes a long‑term vision for growth, development, and overall quality of life. This plan outlines “8 Big Ideas” that will guide decision‑making and community priorities in the years ahead.
One of the Big Ideas is the creation of a greenbelt along Hilliard’s western edge. To support the plan’s emphasis on conservation of open space within the Darby region, the City intends to acquire and preserve land in this area to create an inner-connected greenbelt of land connected by trails. This greenbelt will link neighborhoods with regional parks, forming an integrated open‑space network along the city’s western boundary.
The resulting system will enhance trail connectivity to local and regional destinations, including The Well, nearby Metro Parks, and the Heritage Rail Trail.
The western edge of Hilliard is within the Big Darby Creek Watershed. Big Darby Creek, located about two miles west of this area, is a state and national scenic river and one of the most biologically diverse ecosystems in the Midwest.
The Big Darby is home to more than 100 fish and 44 mussel species, including 38 species that are listed as endangered or rare.
The Darby Creek watershed covers an area of 555 square miles with approximately 6.7 square miles of the watershed in Hilliard.
The Big Darby Accord is a voluntary, multi-jurisdictional agreement adopted in 2006 to protect the Big Darby Creek watershed while coordinating development, infrastructure, and conservation efforts across jurisdictional boundaries.
In 2008, Hilliard and nine other jurisdictions adopted the Big Darby Accord Watershed Master Plan (BDAWMP) – a regional plan with growth and preservation strategies to help preserve, protect, and improve the Big Darby’s unique ecosystem.
The BDAWMP establishes a conservation‑focused growth model that requires at least 50% of every development to remain as protected open space, with overall density capped at one dwelling unit per acre.
Hilliard has chosen to go even further. In a deliberate effort to safeguard the Big Darby watershed and strengthen long‑term environmental resilience, the City requires 70% of all residential development and 60% of all commercial development to be preserved as open space — far exceeding the plan’s baseline standards. This enhanced approach underscores Hilliard’s proactive commitment to sustainable growth and the protection of one of the region’s most valuable natural resources.
In 2025, Accord partners initiated the first comprehensive update to the plan in nearly 20 years. The Draft Big Darby Accord Amendment reflects new scientific data, updated land-use patterns, and lessons learned from implementation.
The draft maintains the Accord’s core mission of protecting water quality and sensitive ecosystems while refining how growth, conservation, and infrastructure investment are coordinated across participating communities.
Key elements of the draft amendment include:
The City of Hilliard is an active participant in the amendment process and remains committed to balancing environmental stewardship with responsible growth. Public review and engagement opportunities will continue through early 2026 before the amendment is finalized.
The draft may be viewed here.
The original plan was adopted in 2006 and has not been updated since. Growth patterns, land costs, infrastructure conditions, and environmental science have changed significantly, and some original goals, such as consistent water-quality monitoring, were not fully implemented in the original Accord.
The draft Amendment maintains the existing 20,000 ERU cap for sanitary sewer connections established in 2006 for the entire watershed within Franklin County. An Equivalent Residential Unit is a billing unit for the amount of storm water runoff from the impervious area of the average-sized residential parcel. As of late 2025, approximately 13,850 ERUs are still available for use.
The Amendment recommends that remaining development be focused near the urban edge of the watershed to reduce environmental impacts and preserve more open space elsewhere. The Amendment does show higher levels of density within some portions of this urban edge where developments could be up to 48 units per acre. However, Hilliard maintains a 1 to 1.5 units per acre standard in our zoning code consistent with recent projects that have been approved.
Most of the development regulations for the Darby region in the City of Hilliard are governed by zoning code. The BDAWMP requires at least 50% of every development to remain as protected open space; however, the City requires 70% of all residential development and 60% of all commercial development to be preserved as open space — far exceeding the plan’s baseline standards.
As a participating member of the Darby Accord, the City recognizes that the protection of the Big Darby watershed is inherently a regional responsibility. Development occurring beyond our municipal boundaries can affect the health of the watershed, and projects located within the Hilliard City School District, but outside the City of Hilliard, likewise have implications for our regional partners.
The draft establishes defined water-quality goals, a funded monitoring program, and standardized pre- and post-construction of water quality testing. Notably, the Amendment would increase stream setbacks to 150 feet on each side of the stream, providing larger buffers where no development can occur near streams.
The increase in stream setback requirements will better protect waterways from the impacts of development. The Amendment maintains a 50% open space standard for development in the Darby watershed and would allow flexibility in having a portion of the open space be located off-site. In Hilliard, developments will still be required to meet our higher 70% standard for residential development and a 60% standard for commercial development.
The draft amendment is being released for public review and comments. Residents are encouraged to review materials and submit comments in the form below.
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