The Fort Collins City Council adopted the Water Supply and Demand Management Policy (PDF 185KB) in September 2003. (Detailed report - PDF 3.8 MB) The policy states, "The reliability of the Fort Collins water supply should be maintained to meet at least the 1-in-50 drought event in the Cache la Poudre River Basin."
Fort Collins Utilities defines a drought as below-average runoff from the Cache la Poudre River. Droughts are measured by:
- Duration (or run length)
- Cumulative deficit below the average
- Average annual water shortage
Through statistical analysis, City officials determined the worst drought that could occur every 50 years in the region. This is called a "design drought". The Fort Collins Utilities staff uses the "design drought" to determine Fort Collins' current and future water supply needs. This "design drought":
- Lasts six years
- Has a run-off that is 550,000 acre-feet below average
- Has annual river volumes about 70% of the Poudre River's long-term average
