GGLSA Focus Areas for 2007 – 2009:  Water Quality
Project Background & History

Water quality in Grand Lake is only partly dependent on natural flows from snowmelt originating in Rocky Mountain National Park.  The East Inlet and North Inlet streams which provide this water are part of the Colorado River headwaters.  The Adams tunnel, located at the eastern end of Grand Lake, provides water to Northern Colorado Water Conservancy District (NCWCD) customers living along Colorado’s Front Range.  Adams tunnel is but one part of a complex water system known as the Colorado-Big Thompson Project.  CBT includes many man-made reservoirs and diversions that collect Colorado River water further downstream and transport it “backwards” through Grand Lake and into the Adams tunnel.  Granby reservoir, the Farr pumping plant, the Granby pump canal, and Shadow Mountain reservoir were all constructed as part of the CBT and serve to collect and transport water in this way.  The originators of the CBT Project laid out their plans in great detail in a series of volumes published in 1937.  However, they did not expect that Shadow Mountain reservoir would become a source of the weeds, algae and algal toxins that now proliferate there.  These materials then appear as unnatural contaminants to Grand Lake itself.  The links on this page will take you to a broader discussion of the facts behind the degradation of Colorado’s largest natural lake.  GGLSA has provided copies of this material to many other groups and agencies.  Our goal is to stimulate the discussion and implementation of alternative less-harmful approaches that will fulfill the needs of NCWCD water users while protecting the lake for future generations. White paper written by John Stahl DEGRADING WATER QUALITY AND REQUEST FOR MITIGATION.