Blog module icon

Displaying all posts tagged with:


Mar 25

FAQ: Can MMWD Build Bigger Reservoirs?

Posted to MMWD Blog: Think Blue Marin on March 25, 2016 at 4:26 PM by Ann Vallee

Especially  in  a  rainy  year  like  this  one,  customers  ask  if  we  can  enlarge  our  reservoirs to hold more water by raising the dams. While creating additional storage may seem like good insurance against drought, it is not as simple as it sounds.

MMWD’s rights to divert and store water are granted by the State of California. The state has authority over how much water we can legally take from our local creeks to store in our reservoirs. As part of our agreement with the state, MMWD is required to maintain a certain amount of water in the creeks for fish habitat. This means  we  actually  release  water  every  year  from  our  reservoirs  into  the  creeks,  but  with  good  reason.  Endangered  coho  salmon  and  other  species  living  in  the  creeks need an adequate flow of water to ensure their health and survival. In 1980, when the district last requested state permission to expand storage, the result was 15 years of studies and hearings prior to reaching a court-ordered agreement that required  us  to  release  more water  annually.  In  summary,  since  the  state  will  not  allow MMWD to divert and store more water, increasing the size of our reservoirs would not provide any benefit.

The  simplest  and  least  expensive  way  we  can  maximize  our  water  supply  is  through conservation, not by creating new or bigger reservoirs. That’s why we ask our customers to use water wisely and why we offer a variety of conservation programs and rebates to help. Thank you for doing your part!
Feb 24

Lagunitas Coho – The Year in Review

Posted to MMWD Blog: Think Blue Marin on February 24, 2015 at 2:03 PM by Ann Vallee

by Eric Ettlinger, Aquatic Ecologist

The final update on Lagunitas Creek coho for the 2014-15 season is somewhat overdue because of some unusually late spawners. Last week we observed eight fresh coho in Lagunitas Creek, which is exceptionally late for a run that peaked in mid-December. Coho are typically seen spawning in February only when the rainy season is delayed, like last year. Given this year’s early rains the best explanation I have for the extended run is that the parents of these fish may have been late spawners. Back in 2012 the last coho of the season were seen spawning on Valentine’s Day.

So, moving on to the postmortem … The best that can be said about this run is that it wasn’t smaller than the coho run three years ago, which is something. Our preliminary season total is 131 coho redds, or about 65% of average. This does not include spawning in Olema Creek or the tributaries to San Geronimo Creek, which are surveyed by the National Park Service and the Salmon Protection and Watershed Network (SPAWN), respectively. The marine survival rate of these fish was under 4%, which is well below the average of the last eight years.

The picture was brighter for other species. We counted the highest number of Chinook salmon redds (23) in eight years and the highest number of chum salmon (3) in a decade. The steelhead run got off to a late start due to the exceptionally dry January, but is now in full swing. To date we’ve seen 70 steelhead redds, which is approaching average for late February.

 lamprey pair -sm (2)
 Pacific lamprey pair
Finally, we saw the first Pacific lamprey of the season on January 29. We typically see these native, cartilaginous fishes spawning in March, as we’re wrapping up our salmonid spawner surveys. Our AmeriCorps members took this great picture of a pair using their sucker mouths to pull rocks from their redd. Their eggs will hatch into worm-like ammocoetes that will spend as much as seven years filter feeding in the streambed. Then they will migrate to the ocean and find a larger fish to latch on to and parasitize. They aren’t able to navigate back to their natal stream like the salmonids do, but when they’re large enough they’ll let go of their host and follow the scent of juvenile lamprey pheromones to whatever stream they’re close to. Like the salmon, this is a one-way trip and they die after spawning. Lamprey will continue to spawn in Lagunitas Creek through the spring.

Jan 14

The Rain Returned, but the Salmon, Not So Much

Posted to MMWD Blog: Think Blue Marin on January 14, 2015 at 2:11 PM by Ann Vallee

by Eric Ettlinger, Aquatic Ecologist

What started off as an unusually large and early coho run in Lagunitas Creek appears to be coming to a disappointing end. We may see a few fish spawning in the next couple of weeks, but at this point a late surge is unlikely. To date we’ve counted 103 coho redds, which is similar to what we saw three years ago but barely half of average. What’s most disappointing is that in 2013 we observed a robust emigration of coho smolts from the creek. We expected those relatively large fish to pack on some more weight in the restored Giacomini Wetlands and then survive well in the open ocean. It now appears that less than three percent of those fish have returned.

It’s possible that we missed some spawning while 15 inches of rain fell and high stream flows kept us out of Lagunitas Creek in mid-December. If that’s true, we should have found redds, live fish, or even carcasses when we returned to the creek, but we saw few of each. We also surveyed the tributary streams during that period and saw relatively few salmon for that time of year. There’s little option but to conclude that this year’s cohort survived poorly in the ocean.

On January 5 we saw our first steelhead spawner of the season and once the rain returns we should see steelhead numbers ramp up. We’re still seeing a couple of Chinook salmon in the creek, and yesterday had the distinct pleasure of seeing a small mixed school of coho, Chinook, and steelhead holding in a deep pool. It wasn’t much, but we’ll take what we can get.