Mill and Cascade Creeks (Pennsylvania)

Watershed Characteristics

Mill Creek (above the Tube, below the Erie Zoo)

Mill and Cascade creeks are the two largest tributaries to Lake Erie’s Presque Isle Bay at Erie, Pennsylvania. Their total watershed area is approximately 25 square miles, draining portions of Erie County.

Land use within these watersheds is approximately 80 percent urban, with a trend toward further development. As with other areas of rapid urban development, water runoff contributes heavily to waterway pollution. The Bay has suffered from accumulation and degradation of wastes discharged by both point and non-point sources.

Modeling Approach

Composite landuse map of the study area

Gannon University completed a Soil and Water Assessment Tool (SWAT) hydrologic model to examine flooding issues for Cascade Creek. The Tributary Modeling Program was able to use this work as a starting point to expand to sediment modeling for both Cascade and Mill creeks. Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling was used to develop a GIS database and update land use/land cover data. SWAT and BASINS modeling were then used to evaluate sub-watershed sediment transport and yield. SWAT predicted the effects of the gradual conversion of land use from undeveloped land to a highly urban scenario.

Modeling was completed in August of 2004. A training workshop for state and local partners took place in September of 2004.

Use and Applications

Cascade Creek (eroded stream bank south of 8th Street on the main branch)

Erie County Planning GIS staff will provide support and training to peripheral users such as the Port Authority, the Erie County Department of Health,

Pennsylvania Department of Environmental Protection (DEP), the Erie Sewer Authority and various watershed associations. The Erie County Soil & Water District will use this model to assess best management practices and their effects on erosion in the watershed. The Pennsylvania DEP will use the model to assess the water quality parameters of the creeks and the health of the basin to facilitate the delisting of the Presque Isle Bay Area of Concern (AOC) by the US Environmental Protection Agency.

Project Partners

For More Information:


Mike Voorhees
USACE, Buffalo District
1776 Niagara Street
Buffalo, NY 14207
Phone: (716) 879-4488