Silver Lake Ditch water rights come from two sources: direct flow and storage rights.
Direct flow rights come from Boulder Creek and were filed in 1888. The Ditch is allocated 10 cubic feet per second from Boulder Creek until the spring runoff is over and direct flow rights move out of priority. The Silver Lake Ditch rights are ‘junior,’ since the first diversion of water from Boulder Creek was in 1859.
Storage rights come from the Silver Lake and Island reservoirs. The men who started the ditch company built the Silver Lake Reservoir in 1887 and Island Lake in 1890. These were some of the earliest storage rights filed in Boulder County and so are quite ‘senior.’
Physically, the water comes out of Boulder Creek west of the mouth of the canyon. It enters the man-made Silver Lake Ditch at an elevation that is high enough to enable it to reach all the way to north Boulder. The water traverses the front range, gradually getting lower in elevation, and ultimately flows as far as Mesa Reservoir (see map on the Welcome page).