Sonoma Creek dries up – Kenwood Press News
Stewardship by landowners by the creek is more necessary than ever if young rainbow trout are to survive the summer of 2021
By Steven Lee
Have you seen the coves lately? They’re about as dry as they’ve ever been, at least in memory of this Sonoma Valley native. After a very good year of rain in 2019 (67.5 inches here at Glen Ellen by the Sonoma Developmental Center) and an average annual rainfall of about 35 inches, we were only 24.9 inches in 2020 and barely 14 , 0 inches so far in 2021.
Last year the seasonal streams stopped flowing early, around June or so, and this year we never even saw a flow in most of the seasonal streams. Here at the Sonoma Ecology Center, we’ve been measuring stream flow around the valley since 2015, with additional resolution since 2017 in the upper section of Sonoma Creek, critical for rainbow trout, between Eldridge and Kenwood. This summer, Sonoma Creek started the dry season with a lower flow rate than measured at the end of the 2020 dry season (less than 1 cubic foot of water per second)! Towards the end of last summer, Sonoma Creek completely stopped flowing near Watmaugh Road. This year, by mid-August, it had already dried up in a series of isolated basins until at least as far as Agua Caliente Road, with just a trickle of runoff crossing Glen Ellen to the vicinity of Sonoma Mountain Road. , where the continuously flowing Graham Creek connects. in.
Groundwater entering this section, from Graham Creek to Kenwood, is what sustains the dry season flow into the rest of Sonoma Creek, and this is the reason we continue to have rainbow trout. rainbow in this watershed. Young rainbow trout must spend two or more summers in the stream before migrating to the ocean. Good flow and cool, deep pools are essential for their survival.
The importance of this section of the creek is why we started our Sonoma Creek Stream Stewardship Program in 2016 with a grant from the California Wildlife Conservation Board (WCB). The purpose of this program was to study the flow patterns in the creek and to work cooperatively with all landowners who still pump water from the creek to help them find alternative solutions for their irrigation needs ( yes, it remains conditionally legal, but is not recommended). No one pumps huge volumes of water from Sonoma Creek, but many smaller diversions remain in this wet section to irrigate lawns and garden beds, and they collectively impact dry season flow, especially in a year like this when the stream dries up to a trickle.
Most years the problem is not a lack of abundant water in the watershed as a whole, it suddenly arises during very flashy storm events and rushes down the stream channels instead of seeping in. in the ground and recharge the aquifers. So, with less water to seep out of the ground later, stream flow does not last as long in the summer as it should. If the stream is to be relied on for its water needs, it is better to pump and store the water in winter or spring when it is plentiful than to do so late in the dry season when the rainbow trout. sky needs it most to survive.
Better yet, it’s best to use a rainwater harvesting approach that completely eliminates the need to pump the stream. This is the approach I have taken on my own property, and I have filled my system with about 60,000 gallons this year even with the light rain we have received! As part of our program, two of these stream water users agreed to follow this stewardship approach and signed letters of support for a subsequent CAT grant, recently awarded to the Sonoma Ecology Center. The grant includes funding to help two or more landowners develop water storage strategies, making dry season stream diversions unnecessary. One of these landowners ended up following my lead and instead pursued a rainwater harvesting system for his irrigation needs. Two other landowners have signed on to plan larger scale water storage and infiltration projects on their properties.
Another landowner, Mark Brewer, completely stopped drawing water from the creek this year. After seeing dramatic changes in stream flow over the past few years, Brewer had already sharply reduced his use of stream water during dry seasons. He is so committed to this that he is ready to take a leading role in encouraging others to follow suit.
To be clear, this is not about demonizing the choices and actions of some landowners. In fact, we all have a part in this water story, from those of us who depend on spring water sources, to those who draw from wells, including streamside wells, which pump essentially the same water that feeds the stream, but also the deepest of the wells that support, among other things, the production of the wines we all love to drink.
It’s about finding solutions – solutions that help people improve their water security, but also the environment in the process. Stewardship actions like this can help turn the tide and start improving dry season stream flows… maybe not this year, but in the drought years to come. It is very possible that Sonoma Creek will dry up completely this year. There’s a reason we’ve all bought properties along the creek. It was not to look down on the bed of a dry stream!
If you are one of those people who still depend on the stream and could benefit from assistance in planning the installation of a water tank, or if you are interested in collecting rainwater and / or other alternative water storage strategies, please call me at (707) 996-0712 or email me at [email protected] org.
For more information on the Sonoma Ecology Center or to donate, please visit www.sonomaecologycenter. org / donation.
Steven Lee is an aquatic ecologist with nearly 30 years of experience in marine and freshwater research and monitoring. He grew up in the Sonoma Valley, swimming and playing in the same creeks and hills that he now studies at the Sonoma Ecology Center, where he is the senior scientist and director of the research program.