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About The nugget. (Sisters, Or.) 1994-current | View Entire Issue (Jan. 26, 2022)
Wednesday, January 26, 2022 The Nugget Newspaper, Sisters, Oregon WATER: Region9s geology plays a big role Continued from page 1 outside the city limits rely on their own individual or shared wells for their water. All wells are accessing groundwater. Groundwater vs. surface water Groundwater is the water that collects or flows beneath the earth9s surface, filling the porous spaces in soil, sedi- ment, and rocks. It originates from rain and melting snow and ice and is the source of water for aquifers, springs, and wells. The water table is an u n d e rg r o u n d b o u n d a r y between the soil surface and the area where groundwater fully saturates spaces between sediments and cracks in rocks. The saturated zone is bounded at the bottom by impenetrable rock or sediment. The aquifer from which the City of Sisters draws its water is a basalt aquifer. Surface water is the water that is available above ground in the form of rivers, streams, oceans, lakes, and wetlands. Surface water is mainly col- lected from precipitation. However, in the Deschutes River Basin, studies have determined there is a hydrau- lic connection (operated by the pressure of water) between groundwater and surface water. Groundwater appropri- ations (wells) have the poten- tial for substantial interference with surface water and could measurably reduce waterway flows. Likewise, low stream flows could reduce the amount of groundwater available to be pumped from a well. What is an aquifer? Aquifers are often iden- tified by the way they were formed. Alluvial aquifers are water-deposited (usually by moving water), and glacial drift aquifers are deposited by the gradual movement of gla- ciers. Large aquifer systems may be composed of several geologic formations, includ- ing both alluvial and glacial drift deposits. Coarse sand and gravel, transported and deposited by rapidly moving water, turns into permeable aquifer depos- its when buried. They can extend laterally from a few feet to many miles and can be paper thin to hundreds of feet thick. The Deschutes Basin aqui- fer has been described as a large bowl, with a deep end near the Cascade Mountains (and Sisters) becoming shal- lower up to the northeast and Madras. Much of the eastern side of the Cascade Range drains into this bowl, which is lined by large areas of perme- able volcanic rock. When the large annual precipitation at higher elevations collects on that permeable rock, the result is a substantial regional aqui- fer system and a stream sys- tem that is heavily dominated by groundwater, with either resulting springs when the groundwater is high or lower water levels when the ground- water level is lower. The headwaters of the Metolius and Fall Rivers, as well as the springs downriver that feed the Metolius, are examples of that groundwater being released. When it comes to water, Sisters is ideally located. Groundwater elevations are highest near the Cascade Mountains in the west and Newberry Volcano in the south and decrease to the northeast and north toward the confluence of the Deschutes and Crooked Rivers. The City only needs to drill down about 300-plus feet to reach copious groundwater. Surface water became the source for irrigation by the early farmers and ranchers in Sisters Country and beyond. A large network of open canals carried water through- out the area. Gradually, over the years, a number of those canals have been replaced by wells and irrigation ponds. In recent years, the Basin to the south irrigation districts central down by have been piping Sunriver. Some the remaining scientists believe canals to stop that the fault leakage into the could be respon- ground. sible for disrupt- For almost ing an even flow 100 years, due of groundwater to those leaky to the east from canals, the entire higher western area had an artifi- elevations. cially high water Long-term table. With the groundwater piping, the water level records in table is returning the central part to its original nat- of the Upper ural level, which Deschutes Basin is leaving some have shown that shallow wells dry, some areas are intermittently or experiencing per- MODIFIED FROM LITE AND GANNETT, 2002 permanently. Sisters lies at an advantageous spot over the region’s water table. sistent groundwa- Increasing ter level declines, water demands Some of the more recent particularly in an area extend- The demands for water in modeling done in the Upper ing from the vicinity of the region are coming from all Deschutes Basin, in coop- Bend, north toward Lake corners 4 a rapidly increasing eration with the Oregon Billy Chinook, and northeast regional population, agricul- Water Resources Department toward Redmond and Powell ture, environmental projects, (OWRD), explores the influ- Butte. The Deschutes Basin hydroelectric, businesses, and ence of well location and geo- Groundwater Mitigation recreation. Additional appro- logic structure on stream cap- Program allows for limited, priations for surface water ture by pumping wells. The additional groundwater devel- have been closed. In a col- OWRD report states: opment using mitigation to laborative effort, a new water <Wells were simulated offset the impacts to the State bank project by the Deschutes at three locations within a Scenic Waterways and spe- River Conservancy will offer 12-mile area close to known cific instream rights. payments to Central Oregon groundwater discharge areas Sister area wells going Irrigation District patrons in and crossed by a regional dry exchange for renting their fault zone. Simulations indi- In the Sisters Country area, water out to the North Unit cate that the magnitude and this past summer, there have for a year. There are several timing of stream capture from been reports of wells going collaborations working on pumping is largely controlled dry, and the need to either possible solutions to a variety by the geographic location of lower the pump or drill an of water-related issues but, the wells, but that faults can entirely new well. Some of where water is involved, each have a large influence on the the reports came from proper- possible solution can also have increase of pumping stresses.= ties on Harrington Loop, Gold unintended consequences. Sisters fault zone Coach Road, and around the Impact of climate cycles In addition to the regional Cloverdale area, as well as Additionally, the current flow pattern from higher Terrebonne and Redmond. It climate cycle has the area in groundwater elevations near is important to remember that a drought, so the amount of the mountains, groundwater most wells, depending on cir- snow melt in the mountains levels in the central part of cumstances, have a lifespan is currently reduced, leaving the Upper Deschutes Basin of 30-50 years and most well less ground and surface water are several feet to several pumps typically last anywhere to meet increasing demands. hundred feet below the sur- from eight to 15 years. Glaciers are integral to the face of the land, indicating In subsequent articles, we Central Oregon ecosystems that stream reaches in the will explore one longtime and economies, and they are central part of the basin are Sisters resident9s experience disappearing, most likely due separated from the regional with wells, what to do if your to regional climate change. A groundwater flow system by well runs dry, as well as water new unnamed lake now sits an unsaturated zone, perhaps as it relates to growth and on the flanks of North Sister along the Sisters Fault Zone development and the political where Thayer Glacier used to which runs from the north- umbrella of more regulated flow. west of the Upper Deschutes uses, higher costs, etc. FUN & GAMES SUDOKU EASY PEASY! MATH SQUARE Place a number in the empty boxes in such a way that each row across, each column down, and each small nine-box square con- tains all of the numbers from 1 to 9. Use the numbers 1 through 16 to complete the equations. Each number is used once. Each row is a math equation. Each column is a math equation. Remember that multiplication and division are performed before addition and subtraction. WORD SEARCH PUZZLE 14