Sunday, July 29, 2007

Mesa Verde waterworks Here's an article about water management in Mesa Verde when the Ancestral Puebloans hung out there, from The Cortez Journal. From the article: Almost every visitor to Mesa Verde wants to see the big cliffside ruins. Not Ken Wright. Since 1995, the renowned Denver water engineer has studied four piles of dirt atop the mesas and in canyon bottoms. Those piles turned out to be reservoirs that were built hundreds of years before Cliff Palace and the other famous villages. But in May, Wright and his wife, Ruth, turned their attention for the first time to the cliff dwellings. They came away more impressed than ever by the smarts and strength of the long-departed Ancestral Puebloans who built Mesa Verde. The Wrights visited Mug House, a ruin in the park's southwestern corner that's closed to the public. They examined a 5,000-gallon cistern about a five-minute walk from the ruin."We were impressed by how they were able to develop water from the mesa top and direct it into a cistern down below. These people were smart. They were good public works engineers," Wright said... Earlier excavations found 5-gallon jugs - about as much as an able-bodied woman could carry. When the cistern was dry, the Puebloans had to make a 3-mile round trip to a spring for their water. Wright hopes to learn how many calories the people spent in water-gathering by the time his Wright Paleohydrological Institute issues its report on the Mug House cistern. The village's inhabitants found a way to capture the rain that occasionally fell. A small slot on the mesa top directed water over the cliff. Down below, the Puebloans built up a wall to hold the water that spilled whenever it rained. "It had a spillway, so when it would overflow it wouldn't wash it out. So it was a nice job," Wright said. The Wrights brought along several people on their Mug House study, including state Supreme Court Justice Greg Hobbs and his wife, Bobbie... As part of the research permit, Wright got the OK to pour a few gallons of water through the slot, to replicate the ancient rain showers that nourished the 50 or so inhabitants of Mug House. The pool is about 5,000 gallons, much smaller than the older reservoirs that Wright excavated. One of them could have held 120,000 gallons, according to Wright... Wright last visited Mesa Verde in 2003, when his team made the last field study in their decade-long investigation of the reservoirs. He published two books on the subject and laid to rest a long debate over the mysterious mounds discovered at the park. Some researchers thought they were dance platforms. But Wright and others suspected they were reservoirs. They stand several feet above the surrounding ground, because they kept filling up with sediment, the same as modern reservoirs. The Puebloans solved the problem of their ever-rising reservoirs by building inlet canals uphill from the reservoirs. Every so often, they would have to build a new canal even farther uphill, until finally the reservoirs were abandoned. Morefield Reservoir remained in operation for 350 years. "That's a long time," Wright said. "That's nearly twice as long as the United States has been a country." Category: Colorado Water 8:19:56 AM     Summit Lake fishery rehabilitation Here's a recap of last Thursday's meeting to discuss the Division of Wildlife's plans to rehabilitate Summit Reservoir, from The Cortez Journal. From the article: In just seven years, white suckers have taken over Summit Lake. Seven years ago, the bottom-feeding fish accounted for about 22 percent of the reservoir's fish. Now at least 76 percent of the fish and 90 percent of the biomass comprise the fish. The white sucker outweighs and outnumbers everything in the lake -- something the Colorado Division of Wildlife is not happy with... About a dozen Summit Ridge residents attended a meeting Thursday night to discuss the Division of Wildlife's plans to kill all the fish in the reservoir next month in an effort to restore its balance. The increase in white suckers has dramatically decreased the water clarity at the reservoir because the bottom-feeding fish stir up the reservoir's clay bottom and make it difficult for light to pass through. On Aug. 29, the Division of Wildlife will dump gallons of rotenone into the reservoir to kill all of the fish. Rotenone is a pesticide that is highly toxic to fish and is derived from tropical plants. "It's relatively safe and specific," said Mike Japhet, senior aquatic biologist for the Division of Wildlife. "As pesticides go, it's one of the safest around." The pesticide kills fish by not allowing them to use oxygen, White said. After the treatment, the lake will take about two to four weeks to detoxify, White said. The lake likely will be closed for about one week after the treatment... The suckers might have slipped in with the original stocked fish, or they might have been brought in by anglers as bait. That is why it is illegal to use live fish as bait, he said. "It's not uncommon for things to get unbalanced in reservoirs," Japhet said. It's also illegal to transport live fish from one body of water to another because a nonnative fish could take over. "We know some folks are moving fish around on us," Japhet said. Twenty-four years ago when the Division of Wildlife used the same treatment to kill the fish at Summit, local residents were allowed to collect the dead fish and take them home, since rotenone is not harmful to humans, other animals or birds. That won't be allowed this year, largely because the Division of Wildlife is worried the fish could carry salmonella -- especially if the treatment is conducted on a hot day, White said... The dead fish will fertilize Summit Lake, making it more productive in spring of 2008 when the Division of Wildlife restocks the water. Summit Lake will be restocked with rainbow trout, largemouth bass, black crappie, blue gill and channel catfish. In 2008 the trout will be abut 10 inches. Category: Colorado Water 8:03:21 AM     Fountain Creek management Here's a look at Fountain Creek, it's history, and problems the watershed is facing today, from The Colorado Springs Gazette. From the article: Today, [Jane Rhodes] is at the table with elected officials from Pueblo, Colorado Springs and Fountain trying to find ways to restrain and reshape the creek. Called the Fountain Creek Vision Task Force, the group of 28 entities, including Sen. Ken Salazar's office, hopes to make the creek a ribbon of trails, wetlands and flood-control projects. "This time," Rhodes said, "we finally are being recognized. Finally we are all sitting at the table to find out what to do. Let's do something." Flooding in the Fountain Creek watershed, which extends from Woodland Park and Palmer Lake to Pueblo, isn't new. Nor is pollution. As early as 1820, an explorer noted in his journal the creek was so befouled with buffalo dung that campers couldn't use the water to brew coffee. Early settlers chronicled how cloudbursts swelled the creek to a "swift flowing river." The creek had devastating floods in 1935 and 1965 and several times since. What's different today is that more people live near Fountain Creek and rely on it for irrigation and domestic water supplies and to dispose of treated wastewater. The creek carries more water than would naturally drain into it, because Colorado Springs gets about 85 percent of its water from transmountain sources and discharges treated effluent into the creek. Those flows will increase if Colorado Springs builds the Southern Delivery System. The pipeline from Pueblo Reservoir, which would bring 78 million gallons a day to a city on the verge of developing an additional 20,000 acres, would double the amount of return flows in the creek from imported water. Today, the creek's average flow is 165 cubic feet per second, of which 37 percent is wastewater discharge. But in 1999, after a heavy snow and pouring rains, water hurtled down the creek at 20,000 cfs, damaging sewer lines and overwhelming the Las Vegas Street sewage plant. About 70 million gallons of sewage spilled into the creek. Erosion carved away acres of soil, prompting about 50 El Paso County property owners to seek property tax reductions because of the loss of land. Rhodes did, too. Her family's 1,500 acres have been shaved by 400 acres through the years, largely in 1999. The creek's 1,000-foot drop in elevation from Colorado Springs to Pueblo County speeds the water... Another hitch is that Colorado Springs has jumped the gun on its flood-control projects, which could complicate the Corps' ability to analyze data. Using money collected from its controversial stormwater enterprise fees, the city is stabilizing banks on Sand Creek and doing other work on Cottonwood Creek, both major factors in the watershed. "They're at the point they can't wait for us anymore," [Charles Wilson, the Corps' plan formulator] said. "They've gotten ahead of us. My concern is the things we come up with in the watershed study, those things don't contradict each other. We want to make sure they work well together."[...] Springs Utilities, too, is busy. It started a sewer system upgrade in 2000 and has fortified dozens of pipes that cross channels. It also spent $10 million on a project that allows the city to divert tainted creek water for retreatment. In addition, the city has shifted its policy on drainage by abandoning concrete channels that speed water along, in favor of requiring developers to detain the water on site to slow its journey. Those steps and the recent push for answers for Fountain Creek are unquestionably linked to the city's plan to pipe water from Pueblo Reservoir. Pueblo County, which has felt the brunt of Fountain Creek's woes, is likely to have authority over how and where the pipeline is built under its land-use regulations. Some Pueblo residents, such as Pueblo Chieftain Publisher Bob Rawlings, oppose the project. The Springs has been busy signing up partners to quell opposition. This spring, it struck a deal with water-rights owners in the lower Arkansas Valley, calling for each to pay $300,000 to draft a Fountain Creek master plan. The city also is active on the task force... The Fountain Creek watershed includes eight municipalities (Woodland Park, Green Mountain Falls, Manitou Springs, Monument, Palmer Lake, Colorado Springs, Fountain and Pueblo) and three counties (El Paso, Pueblo and Teller). Creeks within the Fountain Creek watershed contribute about 15 percent of the drinking water for Colorado Springs and are a source of irrigation for more than 100 farms and ranches. The other 85 percent of Colorado Springs' water is pumped from west of the Continental Divide, and after use, this water is treated and discharged into Fountain Creek. As Colorado Springs' population has increased, so has its water consumption and the runoff from its expanding system of storm sewers. Most of this water winds up in Fountain Creek. The mean annual flow of Fountain Creek has risen from a historical average of approximately 60 cubic feet per second to more than 230 cfs. Flooding and erosion along the creek have accelerated the loss of aquatic and wetland habitats, contributed to the loss of hundreds of acres of productive farmland, and caused the foundations of roads and homes to crumble. Parts of Pueblo's downtown business district lie directly within the historic floodplain of Fountain Creek. Pueblo's history includes devastating floods in 1921, 1935 and 1965. More Coyote Gulch coverage here and here. We had missed the fact that the Gazette ran a series on water issues for Colorado Springs called Great Thirst. It includes several stories and some great graphics. Be sure to check it out. Category: Colorado Water 7:42:36 AM

© Copyright 2007 John Orr. Last update: 8/1/07; 8:19:22 AM.