[3] As of 2016[update], there is a plan to restore part of its pre-Mexican era estuary on lands utilized by the South Bay Salt Works.

[4][5] Savage Dam, completed in 1921,[6] forms the 49,510 acre⋅ft (61,070,000 m3) Lower Otay Reservoir, which is used to supply drinking water to parts of southern San Diego County.

[8] Its predecessor, the Lower Otay Dam was a "rockhill type", which was completed in 1897;[9] it failed in 1916 following heavy rains.

[13] Since the river is used as a municipal water supply, there is no human contact allowed at either of the Otay Reservoirs.

Early testing of manned gliders by noted aviator John J. Montgomery occurred in the region in the late 19th century.