As our cities grew from early settlements to the urban environments that we see today, infrastructure was constructed in an attempt to keep up with growth. Early common practices included using streams to discharge waste from adjacent industries and residences. When those streams became a health hazard, they were piped and covered. This early drainage infrastructure conveyed stormwater runoff as well and were thus, "combined sewers," whose overflows in periods of heavy rain were diverted to nearby water bodies so as not to back up into homes and businesses. But now, as demanded by the United States Environmental Protection Agency (EPA), municipalities must control these combined sewer overflows to mitigate negative impacts to downstream water bodies.

Cincinnati's Problem
As one of the top five combined sewer overflow dischargers in the country, the Metropolitan Sewer District of Greater Cincinnati agreed to create better control in 2010. This included eliminating two billion gallons of combined sewer
overflows from the Lower Mill Creek Watershed by 2018. The proposed gray infrastructure solution was a deep, underground storage tunnel and enhanced high-rate treatment facility at a cost of more than $400 million.

A Better Solution
Beginning in 2009, the design team, led by Human Nature, a landscape architecture firm based in Cincinnati, and engineering firm Strand Associates, developed a watershed-based planning approach that considered Combined Sewer Overflow (CSO) reduction strategies in the context of natural and built systems, as well as community needs. A Sustainable Watershed Evaluation Planning process (SWEP) was put forward to achieve broad-scale community goals in ways that are more cost effective and beneficial to the community than traditional approaches.

Addressing the Lick Run Concern
The Lick Run watershed covers approximately 2,700 acres on Cincinnati's west side and overlaps the Cincinnati neighborhoods of South Fairmount, West Price Hill, East Price Hill, and Westwood. In 1907, the Lick Run stream was enclosed within a 19.5-foot-diameter combined sewer pipe installed below the heart of the South Fairmount neighborhood. In a typical year, approximately 1.6 billion gallons of combined sewage was discharged from the Lick Run watershed directly into Mill Creek, then to the Ohio River. With the long-term sustainability of infrastructure projects in mind, and consistent with the EPA's Integrated Planning Approach Framework, the alternative plan to a deep underground storage tunnel, that the design team identified, promised to significantly reduce CSO volumes, and just as importantly, serve as a catalytic investment in one of the city's most distressed urban neighborhoods.

 
Getting the Buy-in
Input from the community was essential to understanding existing conditions and challenges, as well as specific community goals and priorities. A comprehensive community engagement process, lasting from 2009 through the end of 2012, helped gather public feedback on the Lick Run Alternative Project, and more specifically, the proposed urban waterway in South Fairmount.

Input from a broad cross-section of the community within the watershed, as well as the greater regional community was vital. At each of the community design workshops, attendees provided verbal feedback and worked to complete feedback forms so that every voice could be recorded.

The Proposal
After hearing from all the concerned parties, the design team's proposition included:
Removing stormwater and natural drainage from the combined sewer system through strategic storm sewer separation and natural conveyance.
Conveying separated stormwater runoff through an urban waterway that aerates and cleanses the stormwater.
Optimizing infrastructure with bioretention features.
Demonstrating green infrastructure through stormwater best management practices.
Providing public open space for community recreation.
Creating significant pollinator habitats within an urban environment.
Connecting to adjacent neighborhoods with a multi-use path.
Providing space for future community redevelopment along the urban waterway.

Next Steps
Once the master plan was approved, it was time to get into technical details and construction documents that would lay the groundwork for implementation. A hybrid box stormwater conveyance approach was determined as the safest and most effective option. This allowed the stream to daylight the first flush flows, while also controlling potential flash flooding by placing a box chamber below ground for larger rain events. On top of the box, a stream was fabricated using native natural stone designed to mimic a natural stream with a pool-riffle-run anatomy. At the beginning
of the waterway, water collected from below-grade pipes from upstream stormwater in the watershed cascades down a limestone waterfall.

New bridges were part of the overall scheme. Their architecture was inspired by the historic neighborhood using brick and precast stone for columns. Each cross street was rebuilt to bridge the stream while providing paved crosswalks and corner plazas. Also included were improved streetscapes with stormwater planters, custom decorative rails, and porous pavers. This constructed urban waterway reconnects the watershed landscape with Mill Creek and creates a strong community amenity as a leave-behind. As the stream flows from the narrow confinements of existing roads and buildings, it opens into a recreational area. The lawns and play areas have become amenities for the surrounding communities bringing neighbors and visitors together for planned events and family gatherings. Weaving between all these facilities are walking paths that tie into a multi-use pathway system that runs the extent of the Lick Run Greenway for a total of just over one mile. A visitor is guided by educational panels throughout.

Results Speak for Themselves
The Lick Run Greenway was completed in 2020 after two years of construction. Today, not only is the Lick Run Greenway managing stormwater as designed, but the greenway is also serving as a laboratory for water quality testing and urban habitat. Extensive native meadows along the riparian corridor provide habitat for a variety of bird, insect, and reptile species. The Lick Run Watershed Master Plan exemplifies how a federally-mandated CSO reduction project can be a catalyst for transforming a former industrial urban community and preparing it for the future through infrastructure investment (at less cost than the proposed gray solution) saving over 100 million dollars.

The vision for the urban waterway demonstrated countless opportunities to leverage this investment in ways that could be even more supportive of creating a sustainable, livable, and walkable community of the 21st century to strengthen the greater Cincinnati region.