Grand Lake Clarity

Grand Lake Clarity Documents

Grand County has been working almost two decades with the United States Bureau of Reclamation, Northern Water, and other agencies to improve clarity in Grand Lake, which is Colorado’s largest and deepest natural lake. Why the County has undertaken this work.  Annual reports have been produced since 2010 synthesizing what was known about hydrology and water quality in the Three Lakes (Grand Lake, Shadow Mountain Reservoir, and Granby Reservoir). In 2012 and 2013, the Bureau of Reclamation began a preliminary alternatives analysis to investigate long-term solutions to improve Grand Lake clarity. In 2008, the State of Colorado adopted a narrative clarity standard of “the highest clarity attainable consistent with the exercise of established water rights, the protection of aquatic life, and protection of water quality throughout the three lakes system.” In 2013, Reclamation and Northern Water entered into a “Supplement of Contract” which establishes a long-term commitment to meet the applicable clarity standard(s) for Grand Lake. In 2016, Reclamation, Grand County, Northern Water, the Colorado River District, and Northwest Colorado Council of Governments entered into a Grand Lake Clarity Stakeholders’ Memorandum of Understanding which provides for adaptive management to meet the narrative standard. In 2016, a National Environmental Policy Act process will begin to formally evaluate alternatives to operate or modify the Colorado-Big Thompson Project in a way that can assist in meeting the Grand Lake Clarity Standard consistent with the Project’s primary purposes, as described in Senate Document No. 80:

  1.  To preserve the vested and future rights in irrigation.
  2. To preserve the fishing and recreational facilities and the scenic attractions of Grand Lake, the Colorado River, and the Rocky Mountain National Park.
  3. To preserve the present surface elevations of the water in Grand Lake and to prevent a variation in these elevations greater than their normal fluctuation.
  4. To so conserve and make use of these waters for irrigation, power, industrial development, and other purposes, as to create the greatest benefits.
  5. To maintain conditions of river flow for the benefit of domestic and sanitary uses of this water.