Exotic species and their effect on Pima County's aquatic environments have become a priority issue for those involved with managing aquatic ecosystems in eastern Pima County. Invasion of exotic aquatic species presents a major challenge when preserving and restoring native aquatic species in the region.

Provides background information on improved mapping techniques that have led to a proposal to update the Watercourse and Riparian Habitat Protection and Mitigation Requirements Ordinance adopted in 1994. New riparian classification maps will be forwarded to the Board to consider for adoption during 2003.

Recommends where riparian land acquisitions would be most effective in serving as mitigation that would cover all priority vulnerable species identified in the SDCP. Priority is given to reaches of watercourses.