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 Susquehanna River watershed is the second largest watershed east of the Mississippi River with a contributing drainage area of approximately 27,500 sq. mi. Originating in New York State and flowing through Pennsylvania and Maryland, the Susquehanna River flows in a southerly direction for approximately 630 mi before emptying into the Chesapeake Bay. The Susquehanna River watershed is bordered by the Ohio River to the west, Delaware River to the east, and the Lake Erie Basin to the north. Major tributaries to the Susquehanna River include the Chemung River, West Branch Susquehanna River, and Juniata River.

The Upper Susquehanna River, as defined by NAB, lies upstream of the Chemung River confluence. This portion of the larger Susquehanna River watershed consists of steeply sloped hills and ridges and is largely comprised of farmland.1 However, there are several large population centers, including Binghamton, NY, Johnson City, NY, Endicott, NY, Cortland, NY, and Oneonta, NY. Approximately 500,000 people reside within the Upper Susquehanna River watershed.

Elevations range from approximately 630 ft above sea level near the Chemung River confluence to over 2700 ft above sea level in the northern portion of the Upper Susquehanna River watershed.

The source of the Upper Susquehanna River lies within Otsego Lake, which is near Cooperstown, NY. Flowing generally southwest for a distance of approximately 110 miles, the river passes the villages of Unadilla, Bainbridge, and Windsor, NY. The Unadilla River, which is a major tributary, enters from the west. East Sidney Dam, which lies on Ouleout Creek, provides flood damage reduction along the Upper Susquehanna River downstream of the Village of Unadilla, NY. The Upper Susquehanna River then enters the Commonwealth of Pennsylvania and makes a 180-degree loop of approximately 20 miles. The river then re-enters New York and flows for approximately 20 miles downstream. At this point, the Chenango River enters from the north within the City of Binghamton, NY. Whitney Point Dam, lying on the Otselic River (which is a tributary to the Tioughnioga River and in turn the Chenango River), provides additional flood damage reduction below this point. The river then flows past the cities of Johnson City and Endicott, NY before re-entering the Commonwealth of Pennsylvania approximately 10 miles upstream of the Chemung River confluence.