Kansas City, Missouri 2017-2019
Residents living between North Euclid and North Michigan Streets north of Northeast 78th Street in Kansas City, Missouri, often reported flooding in the street and in the backyards of their homes due to stormwater runoff. An existing aging enclosed stormwater system along Northwest 78th Street discharged into an unimproved and undersized swale along the back lot lines of seven residences there. This runoff then traveled about 300 feet north, before collecting into another stormwater pipe system located in a backyard there. That system runs from the backyards at this location to North Michigan, where it continues north and eventually discharges to a stream on the west side of North Michigan. The residents complained that regular presence of water in the swale was interfering with use of their property and, in some cases, threatening existing structures. One resident on North Euclid reported to the city that a storm event equal to only the 1-year, 30-minute storm recurrence interval could be expected to cause flooding sufficient to submerge an electrical utility enclosure in his backyard by up to one foot, which he perceived as a safety hazard. Field investigations confirmed the electric enclosure was at risk of being undermined, and that scouring was occurring due to the flooding.
As part of its certified Small Local Business Enterprise indefinite-delivery/indefinite-quantity on-call contract to provide a range of engineering, survey, technical and project-management services for the City of Kansas City, Water Resources Solutions was tasked with finding a workable solution to this problem, which was originally estimated by the city staff to be a $430,000 project.
WRS engineers created a hydrologic model using the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) per Kansas City’s requirements for a watershed greater than five acres in size. They created a basin model determining flow properties for existing and proposed inlets and piping, including watershed sub-basins for each curb and area inlet.
WRS’s resulting proposed improvements include replacing the stormwater pipe system along NW 78th Street with a higher-capacity system, as well as continuing the stormwater pipe system north along the back property lines to the point where it could be connected with the existing pipe system. This proposed system will continue along the same alignment as the existing system to discharge into the stream on the west side of North Michigan. In addition, WRS designed an improved overflow swale to be constructed through the backyards above the proposed stormwater pipe system to carry excess runoff to proposed field inlets along the back lot lines. The swale was purposely designed to infiltrate runoff from more frequent storm events in an effort to help improve the stormwater runoff quality for the system.
WRS held regular and frequent meetings with the affected residents, as well as representatives of all affected utilities and city staff, to discuss and address ongoing issues, including utility coordination, temporary and permanent easements, and residents’ concerns that the changes would fully address their original concerns. WRS worked closely with one property owner to incorporate creative use of a stone retaining wall in order to regrade the backyard. Involved project management and innovative design solutions will ensure the city receives full value for the $240,000 final estimated construction cost, a 44 percent saving compared to the original projection.
Client Reference
Bob Davis, P.E., ENV SP
4800 E. 63rd St.
Kansas City, MO 64130
816-513-0573