California Code, Health and Safety Code - HSC § 117055

The department may allow public fishing on any terminal reservoir if it finds that adequate means are being used to protect drinking water quality and that public fishing will have no significant effect on water quality. The department shall examine all feasible means of protecting water quality on terminal reservoirs and other reservoirs where public fishing may be allowed. The department may close any terminal water supply reservoir to public angling on an emergency basis, if water quality is threatened by public use.