7. Report of the General Manager

   a) Lake Merced Update

Mr. Greg Bartow, Groundwater Program Manager, covered two Lake Merced issues: 1) an update on lake levels, and 2) the status of ongoing investigations.

Mr. Bartow stated the latest water addition ended on October 17, 2003, resulting in another 2-foot increase in lake levels. He stated water additions were done for two reasons: 1) to increase beneficial uses by increasing water levels of the lake, and 2) for scientific study purposes to better understand the volumes of water needed to be added to the lake for long-term maintenance of lake levels. He stated the lake was now at 21 feet at gage board. He presented a historic hydrograph of the lake showing the lake levels back to the 1930’s and how the lake level had fluctuated over time by 20 feet. He noted the precipitous climb in the late 1980’s that resulted in the recent attention to raise and stabilize the lake. Current data showed that since October 2002, the lake has been raised 4 feet, largely by supplemental SFPUC water additions and average rainfall. He stated an interim plan on lake-level management was being worked on and would be brought before the Commission in the Spring.

Mr. Bartow stated the results of recent investigations relative to setting a long-term lake level range had been posted on the website. He stated various lake level elevations and supplemental water sources were being considered. He stated as the lake level is raised, the lake becomes a larger surface water body of about 25 acres, of which there would be 25 acres of shoreline habitat to investigate in terms of the effects to the riparian and wetland habitat and balancing them with the other beneficial uses of the lake. He stated it was a key report and one that would figure into the final decision-making process to craft a final Lake Merced water target elevation in coordination with other regulators, such as the Lake Merced Task Force and other members of the public. He stated the report was on the website for public comment through January 8, 2004 and that an extensive update was forthcoming in April 2004.

Commissioner Caen asked if the lake level was holding firm with the water additions, or if there were water losses. Mr. Bartow stated water losses were due to evaporation and going into the subsurface groundwater. He stated the losses at the current lake level were about half a million gallons per day, or about 500-acre feet per year if held at the lake level. He stated the deeper acquifers of the groundwater basin were eventually recharged.

Commissioner Werbach asked how the riparian regeneration was being monitored and if the lake levels were being considered as permanent or as one-time recharges. Mr. Bartow stated in regard to monitoring, a series of transects had been put in the survey and determine changes in biologies. He stated the transects had been created to monitor where the vegetation was relative to new lake levels.

Commissioner Werbach stated there was benefit from high-water events versus a long-term sustained higher level of the lake, and asked if different options were being considered. Mr. Bartow stated the water additions done had been short-term. He stated the lake fluctuated on average 2-3 feet each year—going up during the winter and dropping in the summer. He stated biologists advised that type of fluctuation should be maintained long-term even with supplemental water additions. He stated the summer drop allowed the plant community to be sustainable on the lake fringe. He stated the available water had been taken advantage of for scientific purposes. He stated a final target lake level had not been determined, but that most SFPUC staff and experts agreed that higher water lake levels were preferred, as did the community.

President Normandy commended Mr. Bartow for his role in recent months on the Lake Merced project. He commented on making a distinction between public involvement and public education, stating public involvement was early in the process and education was later on in the process. He stated often SFPUC might make decisions on its own and use public participation to educate the public on its decisions. He stated public involvement was more of a two-way process. He stated it was important in the process of restoring the lake that SFPUC make sure that public involvement was continuous, so that when decisions were made, the public had been part of the process and felt a sense of ownership by contributing to the process.

President Normandy requested that Mr. Bartow meet with Commissioners Werbach and Brooks to orient them on Lake Merced issues, which are among the most important concerns of the Commission.