- Stormwater Analysis & Improvements Evaluation
Burns & McDonnell prepared a stormwater analysis and improvements evaluation for the City of Eureka, Mo. The city has experienced recent growth, which has increased stormwater runoff, ponding, soil erosion and related problems. The city’s objectives for this project were to identify stormwater drainage problems within its incorporated limits and formulate plans and priorities for correcting these problems.
A residents survey was jointly formulated by Burns & McDonnell and the city and was sent to all residents inviting them to describe stormwater problems around their property or subdivision. The survey also invited residents to express their priorities for the future of stormwater management within the community. Approximately 250 responses were received. Surveys reported standing water, creek overflows, street flooding, basement flooding, damage from erosion and other problems.
Burns & McDonnell created a geographic information system (GIS) database for computer analysis of stormwater problems within Eureka. The ArcView extension HEC-GeoHMS was used to develop hydrologic parameters for the HEC-HMS model that estimated stormwater discharges through all watersheds within the incorporated area. Then the ArcView extension HEC-GeoRAS was used to construct the model skeleton for the HEC-RAS hydraulic model. The HEC-RAS model computed water surface profiles across all watersheds.
Detention basins have been built near recent developments throughout the city, and these have a beneficial impact reducing peak storm flows. In several cases, the older detention basins were found not to function as well as intended.
A list of stormwater problems was developed from the residents survey, field inspections and the modeling analysis. Over a dozen projects were formulated and prioritized for city consideration. Projects included:
- Reworking certain detention basins
- Upgrading sections of channel
- Stabilizing banks at critical locations
- Raising sections of low-lying, highly traveled roadways
- Improving conveyance of overland flow
High priority projects were those benefiting the greatest numbers of property owners at the least cost.