Fate of Amalga Barrens Dam tossed around at meeting
By Jessica Warren
The issues of the proposed Amalga Barrens Dam were gutted open at the Bridgerland Audubon Society's monthly meeting Thursday night.
Five panelists spoke on plans and problems associated with the site including soil influences on the water quality, potential earthquakes from three nearby fault lines, and wildlife preservation.
The dam site proposed is at Barrens, a saline wetland west of Logan. The Bear River will be brought into the dam to catch the water before it flows into the Great Salt Lake. Salt Lake and Weber Counties will need the water by 2015 at the earliest, for $400-$500 an acre/foot. The proposed dam will be 66 feet high and 5,400 acres of surface area.
Upgrades to the West Cache Canal pump station will be needed to lift the water out of the river and into the reservoir. Pumping will be done most of the time rather than piping the water. The desired yield of water is 242,000 acre/feet. This can either be done by one dam with the entire amount, or two dams, one at Barrens and one at Honeyville, or another site, reducing each reservoir to 100,000 acre/feet.
Dr. Janis Boettinger of the USU department of soils and biometeorology spoke on the potentialwater quality of the Barrens Dam. With high quantities of salt in the soil, and the major source of water being natural saline springs, Boettinger questions the quality of water, and even the future health related qualities of the water.
The limit of salt in the water is currently 500 milligrams per liter (mg/L) in the United States, and 1,000 mg/L in Utah. Anything over 1,000 tastes salty. Irrigation water is set at 700 mg/L. In the spring, when the water is high, salt content after five years of having the reservoir, and half of the water being used, the content will be at 958 mg/L at a high estimate, and the number goes up with time.
Boettinger questioned the possibility of mitigating (recreating) the Barren's saline wetland environment. An estimated cost done by her department came to $22 million including 10,605 tons of crude salt to replicate the salinity of the water.
She also says that there have been documented poor success of mitigating saline wetlands, especially with the seasonal flow of water at Barrens.
Another concern of the society was brought up by Dr. Susanne Janecke of the USU department of geology. She pointed out the possible effects to the dam if an earthquake should occur. Typical earthquakes in Cache Valley register from 6 to 7 on the scale.
From the fault line, the greatest ground shake occurs six to ten miles out from the mountain front. With the West Cache fault and the East Cache fault running north and south on either side of Barrens, maximum ground shaking estimates run right through Barrens.
The Dayton-Oxford fault has been dormant since Lake Bonneville times, so the exact location is unknown, but generally runs in the area of Barrens. Janecke pointed out the possibility of putting the dike directly across the fault line. In the event that it erupted, surface rupture could cut the dike.
Soft sediment in Barrens also amplifies ground shaking according to Janecke. Liquefaction, which causes loss of strength in the soil can cause mini tidal waves and landslides in the reservoir.
Ron Ryel, an Independent Systems Ecologist, and Wildlife Biologist spoke of the danger of dam to the wildlife. Barrens is habitat to 154 bird species, 105 annual bird users, and 29 primary users. It is also habitat for 24 mammal species, five amphibian species and four reptile species.
The diversity of Barrens have nine major categories to cater to many different kinds of species' necessary habitat. The rarest of these is a seasonably wet playa, which means a seasonal saline wetland. Others include a wet meadow, marsh, open water, upland grassland, pasture, cropland, roadside, and feed lot. Barrens supports a variety of complicated species that need more than one habitat adjacent to one another to survive. The dam, according to Ryel, would reduce habitat diversity.
Specifically, Barrens hosts three of the four threatened or endangered species in Utah including the bald eagle and peregrine falcon. Of the declining population list, eight of the twelve species use Barrens, six are regular users, along with 11 of 22 sensitive birds. Ryel points out that the primary reason these species are decline in numbers is because of loss of habitat. Mitigating is not a guaranteed solution.
Despite these apparent blockades, Dennis Strong, assistant director of the Utah Division of water Resources says plainly that a dam or reservoir will be built. With a time period of five to seven years to get all the assessments and evaluations and permits completed, a dam will be a reality.
Strong says that in deciding a site for the dam will depend on cost and public input. They will also work with Water Conservancy Districts. Cache County currently has no district, but a Water Policy Advisory Board. The decision to form a district will be voted upon in a special election on February 2nd.
According to Strong, a district pulls more weight that the advisory board with his division in discussing possible sites and future water issues in the county, because of the emphasis on government entities representing the entire county.
Larry Anhder of the Cache County Council and chairman of Cache Water Policy Advisory Board stated that a water district would help gather local data without competing with outside entities.
Citizens addressed these panelists with concerns they had about the dam. Most asking if there were any other alternatives to Barrens. For example, increasing the walls at Willow Bay and piping the water there. Strong replied that with settlement, the walls have sunk 15 feet and couldn't hold the extra water for any significant time period. Willow Bay also has a worse water quality than Barrens with respect to salt quantity.
Water conservation was brought up as an alternative to building a dam at all. Strong replied that the division is using schools as an educator to teach students about the importance of water conservation, however, he does point out that most of the water consumption comes from landscaping the desert environment.
The need for the water is necessary, and the Bear River is the last available source. Anhder pointed out that directly from an address from Governor Michael Leavitt, the Bear River will be the next area for development.
At the root of this issue, according to Strong, is growth. Utah has chosen growth as its top priority, and with that comes needs for things like Barrens Dam. It will be expensive, but it is the second lowest cost option next to Honeyville. Treatment will be expensive, mitigation will be expensive, but the dam is a reality, and Strong's experts say that it can be done.