[2] During periods of heavy runoff, the two creeks raise the level of the slough and the water moves at significant speed.

[7] The Rodman Slough wetland areas and the oak woodlands that surround them have a large rookery of great blue heron (Ardea herodias), where migrating birds congregate in the fall.

Other birds include American white pelican (Pelecanus erythrorhynchos), Canada goose (Branta canadensis), cormorant (Phalacrocoracidae), heron and egret (Ardeidae) and grebe (Podicipediformes).

Robinson Lake was a mosaic of shallow wetlands, meandering channels, riparian forest and open water.

[3] The heavy earth-moving equipment used to "reclaim" about 2,000 acres (810 ha) of wetland was one of the causes of a surge in sedimentation in Clear Lake after 1927.

[13] In 1978, the Federal Emergency Management Agency (FEMA) determined that much of the area covered by the flood control project was in the 100-year floodplain of Clear Lake.

It supports herons, red-tailed hawks, osprey, songbirds, waterfowl, deer, gray fox, bobcat, and coyote.

The Army Corps would cover 65% of the costs, but the water district had to compensate over 60 private property owners, raise a section of California State Route 20, reinforce seven PG&E power line pylons and replace a bridge on the Nice-Lucerne Cutoff.

It may be valuable to sensitive species such as the Western pond turtle (Actinemys marmorata), foothill yellow-legged frog (Rana boylii), California red-legged frog (Rana draytonii), tricolored blackbird (Agelaius tricolor), double-crested cormorant (Phalacrocorax auritus), osprey (Pandion haliaetus) and bald eagle (Haliaeetus leucocephalus).

[7] In June 2019 the Lake County Watershed Protection District accepted $15 million from the California Department of Water Resources to purchase and maintain properties affected by the ongoing Middle Creek Flood Damage Reduction and Ecosystem Restoration Project.