Celebrate our beautiful Loch Lomond and learn about water quality at the Great American Secchi Dip In. Hidden in the redwood hills this 175-acre reservoir supplies water to Santa Cruz and the surrounding area. Grab a secchi disk and find out why water transparency matters for the reservoir and all of us that live downstream. RSVP below! Loch Lomond Reservoir is located on 100 Loch Lomond Way, Felton. From Santa Cruz: Take Graham Hill Road towards Felton. Just after you cross the railroad tracks, turn right onto East Zayante Road. Go about 2.5 miles to Lompico Road. Turn left. Go about 1.5 miles to West Drive. Turn left. Go about 3/4 of a mile to Sequoia Drive. Turn right. Follow Sequoia Drive to the entrance.