Because the SacoRiver flows primarily through the White Mountain National Forest, the continued presence of a large contiguous forested riparian habitat, capable of supporting a diversity of wildlife species, is assured.
A 1983 SacoRiver Basin Study by the U.S. Department of Agriculture listed that 56 species of mammals, 165 species of birds, 32 species of amphibians and reptiles, and 36 species of fish are supported by the river and the surrounding forest habitat.
Historically, the SacoRiver was one of the premier trout fishing rivers in the Northeast.
In the 1800s, the SacoRiver served as an integral harbor and port-of-entry for the textile mills of Saco and Biddeford.
The Corps has also dredged extensively to maintain a navigable inlet at the Scarborough River at the northern end of Saco Bay (Table 3), however the majority of dredged material was discarded through offshore disposal.
In 1991, the Maine Department of Environmental Protection and City of Saco requested a study by the Corps under Section 111 of the River and Harbor Act of 1968 (PL 90-483), suggesting that the northern jetty of the SacoRiver navigation project was responsible for erosion problems in the area.