Annual LADWP compliance reporting onlineAugust 11th, 2012 by Greg, Information & Restoration Specialist
Each May, the Los Angeles Department of Water & Power (DWP) submits its annual compliance report to the State Water Resources Control Board. This report contains not only compliance reporting, but the reports from the previous year’s lake and stream monitoring.
Some highlights from the 2011 monitoring include:
- Brine shrimp abundance peaked at over 40,000 shrimp per square meter for seven of the last eight years. This level was only exceeded in five other years during the 1980s (monitoring began in 1982). But it has happened almost every year since 2004.
- The “centroid” of the brine shrimp distribution over time has peaked earlier and earlier each year—as Mono Lake’s salinity has declined, the shrimp have hatched earlier in the spring. But EVERY year since and including 2004 has had an earlier centroid than July 13th. The only year prior to 2004 that had an earlier centriod than that was 1986.
- Annual primary productivity continues its upward trend since a 1997 low—and 2011 was a new high!
- Conversely, brine shrimp cyst reproduction was at the lowest levels ever in 2010 and 2011. Not to worry, though: food availability is a much stronger determinant of the spring generation of shrimp than the previous year’s cyst abundance.
- At the end of 2011, Mono Lake failed to fully mix, initiating the fourth period of meromixis observed since 1983 due to wet year inflows of fresh water. Due to this being a very dry year, it could break down this fall, which would make it the shortest period (1 year) of meromixis observed.
- A small beaver dam capturing spring flow was observed east of the Mill Creek delta. Beaver activity on Rush Creek and Lee Vining Creek has also reached new levels in areas where beavers had not been observed in the past.
- Cain Ranch temperatures during the last decade have stayed below freezing all day on only 40% of the number of days of the previous decade.