Over 60 Colorado water groups want a seat at the table to weigh in on a historic Western Slope bid to purchase powerful water rights tied to a small power plant on the Colorado River. Cities, irrigation districts, hydroelectric companies and other groups submitted filings Friday to have a say in a water court case that will decide the future of Shoshone Power Plant’s rights to access water. The rights are old and large enough to shape how Colorado River water flows around the state. A proposed change to the legal rights has sparked concerns from big dogs in water, like Denver Water, Colorado’s oldest water utility, over possible impacts to their water supplies and a debate that continues decades of west-versus-east water fights in Colorado.