Green Infrastructure Prioritization for Blacksnake Creek Stormwater Separation

The City of St. Joseph's goal for this project is to remove the Blacksnake Creek base stormwater flow from the combined sewer and reduce contribution of excess flows into the treatment plant. The concept includes constructing separate conveyance of creek flow from the area where it currently enters the existing combined sewer system and routing it to the Missouri River. There are a number of viable conveyance alignments, each with inherent risks and rewards. Risks include public acceptance, right of way acquisition, environmental considerations, economic business disruption as well as cost. Some of the rewards can include reduced treatment requirements, improved stream channel conditions, reduced flooding, neighborhood amenities and improvements, public acceptance, and civic pride. Many of these outcomes are related to the more visible aspects of the project including implementation of green infrastructure. This paper demonstrates the process for planning and conceptual design of green infrastructure and real-time control (RTC) runoff management techniques based on weighting of multiple priorities (potential drainage area; volume managed; site constraints such as slope, soils, and outlet into the combined or separated sanitary sewer; estimated project costs; and City of St. Joseph desires). The green infrastructure and RTC evaluation process aims to identify cost effective opportunities that bring the project visibility and public approval while improving stormwater runoff management within the City. The green infrastructure evaluation process includes: information gathering, site screening and identification, conceptual site design, and development of an opinion of probable cost.