For more than a century, Denver and Front Range communities in Colorado have diverted water through pipelines and tunnels from the Upper Colorado River on the west side of the Continental Divide. The Colorado Big Thompson project, which sends water through the Adams Tunnel near Grand Lake, and the Moffat Tunnel, which takes water from the Fraser River, now draw some 60 percent of the Upper Colorado River’s native flows to supply water to the urban areas on the other side of the mountains. Today, most of that water is used to water lawns and gardens, which concerns residents of Grand County and those who recreate there: Should Denver be able to go ahead with two new diversions, which will siphon up to 80 percent of the Upper Colorado’s waters, in order to water expanses of bluegrass? This is a story of the modern west, pitting advocates for water conservation, scientists cautioning about the effects of climate change on water supplies, and people who still still seem to have cavalier attitudes about water use in the high deserts of the western United States. Produced for Trout Unlimited.