As a result, most of the floodwaters can now be harnessed for beneficial use. Kirwin Reservoir provides unequaled opportunities for waterfowl management in a semiarid region. The reservoir lies within the Central Flyway and provides a testing and feeding area during spring and fall migrations and winter months. Tens of thousands of migrating birds visit the area each year and include such rare species as the whooping crane, white-fronted goose, and white pelican. Rolling prairie lands and croplands surrounding the reservoir provide excellent habitat for prairie chicken, pheasant, and bobwhite quail.
Many people visit the area each year to watch the migrating birds.
Recreational activities such as fishing, boating, swimming, camping, and water skiing are popular. The Kirwin National Wildlife Refuge area includes the reservoir water surface and about 10,700 acres of adjacent publicly owned land. The bedrock in the sediments of Kirwin Dam is the Fort Hays limestone of the Niobrara foundation. The Fort Hays overlies the Carlile shale, which forms the bedrock under valley section of the Dam. Both of these formations are of Cretaceous Age.