Category Archives: Naturalist

Yolo Weir Tour on Sunday

On Sunday, I got up around 5:45 in the morning to do all my morning ablutions stuff before heading out to the all-day Yolo Weirs tour.  It was around 61° when we started out, and it got up to around 86° by the end of the tour.  I got pretty sunburned and it was super-windy all day, so we got a lot of dirt blown in our faces.  And O.M.G. what an exhausting day.

I was the first one at the Yolo Bypass Area Wildlife Headquarters (on Country Road 32B in Davis, CA), and no one else showed up for about 20 minutes so I thought for a moment I had the day wrong or something.  There ended up being about 25 people for the tour, and rather than providing vans or trucks or whatever, they asked that we all car pool.  I got into an SUV with a gentleman named John Brennan who was actually one of the speakers on the tour — and he talked and gesticulated all the while he was driving (which both interesting and scary at the same time.  John, watch the road!  Hah!)

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We started off at the head of the Freemont Weir which is north of Woodland.  The weir system has been around for about 100 years, but when it was first planned they didn’t have all the fancy electronic measuring equipment and whatnot, and there was no real coordination of anything, so private land owners were indiscriminately building ad hoc weirs on their land to hold back the flood waters of the Sacramento River without really caring where the water went as long as it didn’t flood their own property.  Water came from a variety of smaller rives and dumped into the Sacramento River (which can hit flood stage at least once a year), but because of the way the valley is tipped, the water didn’t automatically drain down to Southern California; instead, it backed up, flooding everything around Sacramento and the towns north of it.  A hundred years ago, when the river flooded everything came to a stand-still until the waters drained off again…  The city of Sacramento — like the city of New Orleans — is in the middle of a huge flood plain that sits below the river level.  Some of the experts on the tour were laughing about all the developments now taking place in the Natomas area of northern Sacramento: if one weir doesn’t work or there’s a levy break, Natomas will be under water.  The cost flood insurance in that part of town is astronomical.   Anway, now, the whole north state has set up a series of dams and locks and weirs to try to control the flood waters, and most of the time it works.  In 1986 and 1997 when we had several major rain storms come across the state, everything from Shasta Dam to the Yolo weirs worked together to keep Sacramento dry. (And that’s why Discovery Park is under water for several months in some years…  the water just has to go somewhere…)  Joe Countryman, one of the speakers on the tour and an expert in hydrology, says the 100-year-old system is starting to fall apart, however.  Some of the levies and weirs weren’t built correctly — but trying to fix them and bring them up to code is too expensive, so Sacramento County is just hoping that when disaster strikes the cost to rebuild people’s lives will be less expensive than fixing the broken bits of the system.  Yikes!

Anyway, we stopped first at the Freemont Weir which right now is just a cement buffer surrounded by acres of grassland and oak trees.  When the river floods, the waters spill into the grasslands and the weirs control where it goes and how high it gets.  If the flood is a bad one, though, and the water breeches the weir, the levies then have to do their jobs.  Last year I heard on the news that water was spilling over the Freemont Weir, but I had no idea what that meant — until now.  Joe said one time he was out in the field videotaping the water coming over the weir and was startled to see a guy in a kayak come over the weir with it!  Yikes-2!

After this stop we went onto one of John Brennan’s rice farms, Knaggs Ranch (he said it’s tradition in the farming industry that when you buy a farm from someone, you name the farm after the previous owner… so even though Brennan now owns the property, it’s called “Knaggs” after the previous owner).  John’s rice fields are what I drive over every day to and from work when I drive from Sacramento to Woodland and back.  He told us that he has to drain all the fields in March, get them dry and tilled by April, get them all leveled (using a GPS system, so he can get them all to an angle of only 2” from front to back), and get the insecticide and fertilizer down by May 1st, so he can start filling them with water and get the rice seed flown over them before June 1st.   Between September and February, the state had been demanding that he leave the fields flooded for “habitat” purposes (for the flocks of water fowl who stop off here on their way south during the winter).  He didn’t like the idea of having his land just sit there all wet with no income being generated by it, so he proposed a project to the State which is now in its second year.  He said that over the past  decade or so, the salmon fry were getting lost inside the weir system, and large numbers never made it out to the ocean or got out there too early in their cycle and were killed off by predators.  So, he spearheaded a project to hold the fry in his rice fields until they get big and fat enough to release out into the rivers and head to the ocean…  He said last year they had about 100,000 salmon in one portion of his fields, and some of them were so big you could see their humped backs poking out of the shallow rice water.  He’s hoping to do better this year.  It sounded like such an ingenious use of his lands!  When we were out in his fields, he was just starting to flood them.

Another thing he was promoting was to set up lines of trees along his properties, not only as wind-breaks, but also as habitat for ducks and other birds.  He said the ducks often lay their eggs in the wheat fields and corn fields but don’t have anywhere to retreat to if predators come along.  In the rice-field areas, the trees would also help to regulate the temperature of the water by providing shade along the edges of the field where the salmon fry can retreat to when the center of the field gets too hot for them.

After our visit at Knaggs Ranch, we then went to the Settling Basin, which is a plot of land lower than the rice fields, where water from the weirs is pulled in so the sediment can be released from it.  The Settling Basin fills about 8” inches per year, I think they said, and they’re running out of space for it… and the sediment is so full of Boron and mercury that it can’t be used for agricultural purposes… The state and county haven’t figured out yet what they’re going to do when they can’t use this basin anymore (or what they’re going to do with all of the contaminated dirt.  The consensus so far seems to be to cover  it with cement, like Chernobyl.)

We were then off to the Conaway Ranch for lunch — sandwiches and soda.  This is a working cattle and sheep ranch, but parts of it are also wetlands, so they’re focus is trying to find ways to balance out the two… and they’ve apparently been very successful.  (Tuleyome just got a grant to host environmentally focused outings for children and families at the ranch.)  We were supposed to hear all about the ranch from the manager, Mike Hall, but at the last minute some tractor or something broke on the ranch, and he wasn’t able to make it in during the lunch hour.  So, we left there early and went on to see the tiny Lisbon Weir — which is basically a pile of rocks in the tidal wetlands at the end of the Yolo Bypass Wildlife Area.  It’s so weird to think of “tide” affecting things this far inland, but they do.  Right behind where the weir is situated is what looks like a tall levy… but it’s actually the side of the Deep Water Channel that connects Sacramento and San Francisco through the Sacramento River.  Robin Kulakow, who was telling us about the Lisbon Weir, said that there have been a few times when she’s been out in the fields by this area, and could see the top of big ships cruising along the channel.  Hah!  Kewl!

The tour ended with a mini stop at the new wetlands area that just opened up near the Lisbon Weir, and then we all headed back to the headquarters.  It was an interesting day.  Not a lot of walking, but I still got outside and learned some stuff in the process.

For more information about the tours hosted by the Yolo Basin Foundation, CLICK HERE.