[env-trinity] Restoration program public float shares projects, goals
tstokely at att.net
Wed Jul 13 08:20:18 PDT 2016
Restoration program public float shares projects, goals
- By AMY GITTELSOHN The Trinity Journal
- 2 hrs ago
- Amy Gittelsohn | The Trinity Journal
Aaron Martin, habitat restoration biologist with the program, explains the reasoning and history behind a constructed side channel on the river where wood has been added.
- Amy Gittelsohn | The Trinity Journal
Brandt Gutermuth, environmental scientist with the restoration program, prepares to jump off Painted Rock into the river.
The float winds up in the area of Lorenz Gulch.
Trinity River Restoration Program staff took about 40 members of the public on a Trinity River float Thursday to provide them with an up-close look at projects on the river aimed at restoring fisheries affected by the construction of Trinity Dam.The rafts put in at the Steel Bridge Campground and floated a nine-mile section of the river to Lorenz Gulch downstream from Douglas City.A restoration program staff member was on each raft to answer questions and talk about the projects and river. A fisheries biologist with the program, Kyle De Juilio, rowed one of the groups and fielded questions regarding water temperature, gravel entering the river by natural and artificial means, projects and lessons learned. Also on-board was Don Anderson, interim executive director of the program.The release to the Trinity River is steadily dropping at this point after a spring peak flow that hit 10,000 cfs twice in May. It’s thought that the “double-peak” will be more effective at moving gravel placed in the upper river to make up the deficit caused when tributaries upstream of Trinity and Lewiston reservoirs were cut off by the dams.The gravel provides spawning habitat, forms bars and makes for a more diverse river channel, according to program staff.The flotilla moved through an older restoration site in the Vitzthum Gulch area where chunks of vegetation were taken out in a project about 10 years ago.Due to decades of very low flows after the dams were constructed, vegetation formed berms along the river forming “a real confined U-shaped channel,” De Juilio said, locking the river into a “bowling alley” appearance that he pointed out at several locations.The Vitzthum project created some habitat with slower moving water used by juvenile fish, but the flows weren’t enough to keep the notches open and most filled back in with willows.Farther along the route the rafts pulled into a constructed side channel upstream of Douglas City. The side channels are also meant to let the river spread and slow, but this one initially built in 2007 needed some revision, said Brandt Gutermuth, environmental scientist with the restoration program.Fisheries biologists did a snorkel survey and found that fish weren’t using it. It was flowing too fast.It was that undesirable U-shape, noted Aaron Martin, habitat restoration biologist with the program. The project was reworked last year.“We kicked it around so it’s not so straight anymore,” Martin said.Wood was added as well. Martin said this isn’t done with cables but is braced using only dirt, rock and wood. That does mean that things don’t stay right in place.“We want things to be changing and evolving,” Martin said.The result has been increased use by fish.There were questions regarding how the projects are assessed and fish numbers.“We know when we build something like this the fish really like it and they use it,” Martin said.But restoration staff noted that they can’t control everything such as the ocean conditions that also has a big impact on fisheries.There were questions also about the river flow which restoration staff acknowledged at the moment is considerably higher than if the dams didn’t exist — 1,400 cfs on the day of the float. The Trinity River Record of Decision from 2000 determines how much water is released to the river based on water year type.Martin said water is the most important restoration tool, and he tries to bring home to people not just the amount sent down the river but also the amount diverted through pipes for Central Valley Project use. On average, approximately half of the river’s water is diverted.The river restoration program has had its share of controversy, including complaints that the gravel injections have filled in deep holes used by fish. Geomorphologist Dave Gaeuman has said that while there have been instances of holes filling due to widening of the river by the program in spots which reduced water velocity, a sonar study showed that most holes did not change. At one site known as Painted Rock, Gaeuman dove and Brandt Gutermuth jumped into the river from the rock to demonstrate the depth.Gaeuman said, “In the last five or so years we’ve really made an effort to design differently so we’re not impacting those holes.”
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