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)

Genesee River rises in the Allegheny Mountains in Potter County, PA, and flows generally north for about 157 river miles to empty into Lake Ontario at Rochester Harbor, NY. The basin is about 100 miles long and has a maximum width of about 40 miles. The total basin area is 2,466 square miles, of which 1,080 square miles is above the dam. The topography of the southern portion of the basin, above the dam, is steep and rugged, while the lower portion of the basin is gently rolling. Damaging floods on the Genesee Basin have occurred in all months of the year except August. Summer floods are generally localized, and are usually the result of unstable air conditions. Winter and spring floods are usually the result of frontal precipitation on saturated or frozen ground, or on melting snow cover, although floods have been caused from melting snow cover alone. Prevailing winds at various stations range from south to northwest. Average annual precipitation on the basin varies from approximately 25 to 40 inches, with sharp differences between the western rim and the central part of the valley.

Mt. Morris Dam was authorized in 1944 and completed in 1951, and first used for flood regulation on November 24, 1951. Mt Morris Dam is located approximately 67 river miles above the mouth of the Genesee River in Livingston County, NY, and about 4 miles west of the village of Mt. Morris. Mt. Morris Dam is a concrete gravity dam whose primary purpose is reduction of flood damage in the lower
Genesee River. The overall length of the dam is 1,028 feet, with a top width of 20 feet, bottom width of 212.8 feet, and maximum height above the streambed of 215 feet. The uncontrolled ogee overflow
spillway is 550 feet long and located in the center of the dam with a crest elevation of 760.0 feet (NAVD 29). Nine rectangular outlet conduits, each with a 5 foot wide by 7 foot high minimum cross section, are located at the base of the spillway section.

Mt. Morris Reservoir is contained entirely in the deep and narrow valley of the Genesee River between Mt. Morris and the lower Portage Falls. Below the falls, the river flows through a constricted valley for 1.5 miles then through a narrow canyon over 500 feet deep and 3 miles long known as the Portage High Banks. The next 5 miles are through the narrow St. Helena Valley and then through another gorge section, known as Mt. Morris Canyon, for 7 miles to the Mt. Morris Dam. At the top of flood control pool, elevation 760.0 feet (NAVD 29), the reservoir has a total length of approximately 17 miles and a maximum width of about ½ mile. The total storage at top of flood control pool is 337, 400 acre-feet. The area at full pool is 3,300 acres. The reservoir area is rugged and undeveloped, and approximately 50 percent wooded.