City of Gladstone, Missouri

2016

WRS was brought in as the hydrologic and hydraulic design consultant on the Hobby Hill Park Renovation, which included design of a constructed wetland with walking trails and reflection nodes around the wetland.  The existing Hobby Hill Park site provided a unique opportunity for a wetland because three streams/waterways flow through the property and come together in approximately the same location before leaving the site. The 31.9 acre Hobby Hill park is located in the northwest corner of Gladstone, Missouri, and has served as a recreation area for the past 30 years.

Water Resources Solutions performed hydrologic calculations to analyze multiple storm events. Drainage areas were delineated using the most current and readily available LiDAR contour mapping and the existing conditions survey information. WRS used the NRCS curve number method and Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) modeling program to determine the time of concentration and flowrates to the proposed constructed wetland site. It analyzed the water quality, 1-yr, 2-yr, 10-yr, and 100-yr storm events and designed designed the proposed wetland using the HEC-HMS model.

One of the key components to a well-functioning wetland is the regulation of the water surface elevation.  A well-regulated water surface elevation will help the vegetation and wildlife habitat thrive within the wetland. WRS proposed a regulated outfall structure to maintain the water surface elevation of the design storm within the wetland while providing an overflow for the larger storm events.  WRS evaluated the hydraulics of the outfall structure to manage the water quality and stormwater runoff events.  They used appropriate third party hydrologic and hydraulic models as well as proprietary spreadsheets to calculate the hydraulics of the outlet. Special attention was given to the energy dissipation as the flow enters the wetland as well as at the outfall from the overflow structure.

Not only does the newly constructed wetland store and regulate the stormwater runoff from the park property, it also provides a recreational and educational opportunity.  This wetland will be its own ecosystem.  The wetland provides habitat for multiple species including fish, birds, and amphibians.  The wetland plants provide shelter for the animals while also improving the water quality of the stormwater runoff that passes through the wetland.  There will be trails around the wetland with multiple educational signage providing information about the different plants and habitat that the new wetland provides.  Multiple reflection nodes around the wetland will provide opportunities for visitors to relax and enjoy the outdoor setting.  The wetland provides the opportunities for bird watching and observing the multiple species of trees and flowers.