Trout Unlimited and The Nature Conservancy are working to improve fish habitat and riparian health on the upper and lower Dolores River.<\/p>\n
Matt Clark, director for the Dolores River Chapter of Trout Unlimited, is organizing a project to install a fish passage and improved diversion dam at the Redburn Ranch north of Dolores.<\/p>\n
Currently, landowners have to build a cobble push-up dam across a wide section of river every year to get enough draw into a nearby diversion that irrigates the pastures.<\/p>\n
The make-shift dam blocks fish from moving up and down the river and washes out every year at high flows.<\/p>\n
\u201cDuring the nine months out of the year it is up, there is no water flowing over it, preventing fish passage,\u201d said Clark. \u201cPlus it is a pain for the landowner to maintain.\u201d<\/p>\n
The solution is to build three, large-rock dams 200 feet apart that step down.<\/p>\n
\u201cEach one drops down the river a foot and has a pour-over,\u201d Clark explained. \u201cA side benefit is that it forms pools and ripple-habitat structure in between.\u201d<\/p>\n
In addition a new head-gate will be installed for the irrigation diversion.<\/p>\n
Clark said there is anecdotal evidence that juvenile fish are getting trapped in that area of the river.<\/p>\n
\u201cA health trout fishery requires a connected river system,\u201d he said. \u201cWhen fish spawn higher up in the system, their larvae drift down and need to spread out without obstructions.\u201d<\/p>\n
The project is expected to be installed next fall, with cost estimates between $200,000 and $300,000. The Southwest Basin Roundtable has awarded TU $50,000 for the Redburn Ranch fish passage, Trout Unlimited contributed $20,000, and the landowner contributed money as well, Clark said.<\/p>\n
The remaining funds are being raised through grants.<\/p>\n
\u201cWe\u2019re piecing it together,\u201d Clark said. \u201cIt is a win-win for ranch management and fish habitat. Plus the pour-overs allow for easier passage for recreational boat passage.\u201d<\/p>\n
Meanwhile on the Lower Dolores River below McPhee dam, The Nature Conservancy is committed to improving riparian habitat by eradicating invasive tamarisk and planting native species.<\/p>\n
TNC, along with the Southwest Conservation Corp, and the BLM formed the Dolores River Restoration Partnership. So far the effort has created 175 jobs and restored 821 acres.<\/p>\n
\u201cThe impact of tamarisk is huge \u2013 they rob waterways of their health and make recreational access cumbersome,\u201d says Peter Mueller, director of the Conservancy\u2019s North San Juan Mountain Program in Colorado.<\/p>\n
But, he adds, \u201cWhen you get rid of this wicked tree, all of a sudden you can see the light, and you can see the river again.\u201d<\/p>\n
Aiding the effort is the spread of the tamarisk beetle, introduced into the West in the 1990s as a biological control agent. The U.S. Department of Agriculture imported tamarisk beetles from Eurasia, where they keep tamarisk in check, and after years of quarantine and testing, released them in Utah, Wyoming and Colorado.<\/p>\n
\u201cThese beetles are one of the most tested biological agents we have and there\u2019s little risk of them harming other plants,\u201d says Mueller.<\/p>\n
Over the last three years, the beetles have defoliated a majority of the tamarisk on a 60-mile reach of the Colorado River. From the release site in Utah, the insects have now moved into Colorado and the Dolores River watershed.<\/p>\n
The lower Dolores is a more difficult river to tame because damming has altered its flow and flood timing, a condition that favors tamarisk and other exotic species.<\/p>\n
\u201cRestoring the health of the Dolores will require not only tamarisk removal, but improved water management and planting of native species,\u201d Mueller said.<\/p>\n
Native willow, sumac, and cottonwoods are planted, and native grass seeds are spread around where tamarisk once dominated.<\/p>\n