Detailed quarterly water quality monitoring has been ongoing at Lake Merced since 1997. Lake Merced is considered a shallow eutrophic lake, meaning that it is rich in minerals and organic nutrients that promote proliferation of plant life including algae, which can lead to depressed dissolved oxygen levels. The lake is on the California 303 (d) list for pH and dissolved oxygen. Updates on the presence of algae are found here.
The SFPUC conducts quarterly sampling at Lake Merced to monitor the condition of the lake. Results of this sampling and analysis are summarized in the Annual Lake Merced Water Quality Memorandum and are used to determine if there has been a change in water quality at the lake. The 2018 Lake Merced Water Quality Monitoring Memorandum is available here.
Lake Merced Levels
As part of the Watershed Management activities the SFPUC measures and records surface water levels at Lake Merced using an automated pressure transducer. Lake Merced water levels are recorded at least daily and are presented below.
See the lake levels hydrograph. The gap in data was the result of construction activities during the Seismic Upgrades and Retrofit of the Lake Merced Pump Station.