In 1897, water from the lake was used to irrigate the newly built golf course at the Presidio, dropping the water level from its original depth. Park Presidio Boulevard was constructed for the Funston approach directly over the western shore of the lake, which reduced the size of the lake as well. Since runoff from the Funston approach was directed into the lake, golf course pesticides and lead emissions from cars burning leaded gasoline were dumped into the lake over many years. The lake also became a dumping ground for unwanted pets, including crawdads, large-mouth bass, goldfish, carp, bullfrogs, turtles, and even an alligator, which was discovered and removed in 1996.