Distinctly Montana Magazine

d i s t i n c t ly m o n ta n a • s p r i n g 2 0 1 4 50 M o n ta n a i n y e a r S 3 what will be the key water suPPly- anD-DeManD issues fOr MOntanans in 2044? I think the most obvious water supply concern issue will be higher tempera- tures and earlier snow- melt that lead to lower late season streamflows. In addition warmer temperatures will lead to increased loss of rain that falls in the spring and sum- mer back to the atmosphere as evaporation. As the supply of wa- ter decreases we will be faced with increasing demands by growth and development that increase our in- dustrial, municipal and agricultural uses of water. Another concern will be to maintain groundwater stores and in-stream flows for fisheries and riparian and wetland areas that promote water quality. tO what Degree will CliMate Change iMPaCt MOntana grOunD anD surfaCe waters? In general, groundwater is connected to our surface wa- ter and sustains our streams, lakes, and wetlands. These are also the water sources that are most sensitive to seasonal and longer-term climatic variations. As a result, the interaction of groundwater and surface water will also be sensitive to variability of climate. Earlier snow- melt and increased spring and summer temperatures mean that more of our precipitation will be returning back to the atmosphere as evaporation, with less water making it to our groundwater supplies and streams. One of the big challenges for Montana is determining where changes in groundwater and surface water supplies will occur and where they will not occur. When someone mentions that we expect to see a 2-degree warming of av- erage temperature or an increase in average precipitation of 2 inches in the next 30 years for the state, this value is based on our best scientific understanding across the broader Western U.S. The truth is that some parts of the state will change more and some will change less. There has not been a significant investment to understand where and when these changes are likely to occur within Montana. A better assessment of this local variability is imperative if we want to deter- mine how to best sustain activities such as agriculture that depend on water and drive our economy. The Montana Climate Office is working to develop and assess historical and current information on vegetation productivity, evapo- transpiration, daily precipitation and temperature from meteoro- logical stations and satellite-based measurements (www.climate.umt. edu). From these basic data sets we can begin to create new tools and forecasts for the state based on the best available science and observations. We hope that this will better inform water resource managers or farmers, ranchers, and foresters who need to know how to prepare for shifts in water availability. hOw will OutDOOr reCreatiOn be affeCteD by water basin suP- Plies anD flOw? Because spring snowmelt is anticipated to start and finish earlier, we will see lower soil moisture and late summer streamflows decline. On dry years, we will see more potential for smaller streams to dry up in late sum- mer. I have talked with numerous ranch owners from eastern Montana who have witnessed the beginnings of this trend first hand. Lower soil moisture and stream- flow mean fewer river miles for fishing and rafting, and declines in vegetation and forage for deer and elk populations. Because of the potential for less late season recharge we may also experience rising stream tempera- tures and more fishing restrictions to limit mortality. is "watersheD basin ManageMent" the likely MeChanisM fOr allOCating water use in the future? Yes. Relative to other states across the western U.S., Montana has taken a novel approach to water planning. WatEr kelsey JenCsO is an Assistant Professor of Watershed Hydrology at the University of Montana and the Montana State Climatologist. His research with graduate students focuses on understanding the sources areas of stream water quantity and quality in mountain landscapes and how water availability and forest management impact the spatial patterns of forest productivity. At the Montana Climate Office Kelsey and staff are working to provide targeted climate and water information to the people of Montana for specific sectors of interest by either location or resource. Away from the office Kelsey enjoys spending time with his family, fishing, hunting, skiing and generally any other activity that puts him in the mountains of Montana. INtErvIEW WItH kELSEy JENCSo

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