USACE CWMS - Chemung River Watershed

The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin:

- GeoHMS (Geospatial Hydrologic Modeling Extension)
- ResSIM (Reservoir System Simulation)
- RAS (River Analysis System)
- FIA (Flood Impact Analysis)

The Chemung River Basin is located within the states ofPennsylvania and New York. Of the 2,595 square miles that make up the basin, approximately 1,742
square miles or 67% of the basin is in New York with the remaining 853 square miles or 33% within Pennsylvania. The basin is characterized by rolling to flat-topped uplands with steep alluvial valleys.

The Chemung River extends for 46 miles from its headwaters near Painted Post in Steuben County, NY where it is formed by the confluence of the Cohocton and Tioga Rivers, to its confluence with the Susquehanna River in Pennsylvania. Besides the Tioga and Cohocton Rivers, its major tributaries include Canisteo and Cowanesque Rivers.

According to the 2010 census, the population of the Chemung River basin is approximately 223,450, which is about 5.4% of the total Susquehanna River Watershed population. Majority of the population (about 81%) resides in the portion of the watershed that lies within New York. The major population centers in New York include the cities of Hornell, Corning and Elmira. There are several levee systems within the Chemung River basin – Avoca, Addison, Bath, Corning, Painted Post, Gang Mills, Canisteo, and Elmira in New York and Athens, Elkland, Lawrenceville, and
Tioga in Pennsylvania – providing protection to population centers such as the Village of Addison, City of Hornell, Village of Bath, Gang Mills in the Town of Erwin, City of Elmira, Village of Avoca, City of Corning, Villages of Painted Post, Riverside, South Corning, Village of Canisteo in New York, and Cities of
Elkland, Lawrenceville, and Tioga in Pennsylvania.

There are five USACE dams in the Chemung River basin - Almond Dam located on Canacadea Creek, Arkport Dam located on Canisteo River, Cowanesque Dam located on the Cowanesque River, Tioga Dam located on the Tioga River, and Hammond Dam located on Crooked Creek.