Swan Creek Pollution Reduction Targets
An Ohio EPA grant project recently completed by TMACOG’s Stormwater Planner Kari Gerwin helps jurisdictions in the Swan Creek watershed meet water quality standards.
TMACOG developed goals for best management practices in urban areas designed to help communities meet phosphorus load reduction targets. Phosphorus has been identified as a contributor to harmful algal blooms in Lake Erie. Local cities and villages can take steps to reduce the amount of phosphorus that enters the rivers and the lake from municipal storm sewers.
The project built upon earlier TMACOG work that identified sites where practices could be improved and where existing infrastructure could use a retrofit. Data about existing levels of phosphorus attributable to stormwater infrastructure came from sampling done by the Ohio EPA in 2006 and analysis by consultant Tetra Tech.
The final report details for each community the land use, soil composition, estimate of impervious acres, soil type, and total reduction of phosphorus needed to meet goals. Then charts detail different best management practices with an estimate of how much each practice would reduce phosphorus. These strategies include structural and non-structural practices. Examples of structural practices include building wetlands, installing sand filters, and using retention ponds and bioswales. Non-structural best practices include public education about lawn care, cleaning out catch basins, and erosion control. Erosion control is a particular concern at construction sites. Silt fences and other best practices are used to control sediment erosion.
Because most communities where the goals are relevant are members of TMACOG’s Stormwater Coalition and the Swan Creek Balanced Growth Committee, TMACOG anticipates providing support to member jurisdictions as they decide when stormwater best management practices will best help them meet phosphorus load reduction targets.
The study only set goals for best management practices in urban areas. In order to fully meet watershed targets for phosphorus load reduction, best practices will also need to be employed in rural areas. Steps in rural areas could include changes to fertilizing routines, cover crops, and planting of protective strips near rivers.
The map and legend shown here for the Wolf Creek area of the Swan Creek watershed shows how best practices were determined. The map shows land use and identifies areas where suitable retrofits have been identified.