How can it be that the project increases the storage capacity of Gross Reservoir by 72,000 acre-feet but provides an additional 18,000 acre-feet of new supply?
We have determined we will need an additional 18,000 acre-feet of water supply every year. However, in order to ensure we have that amount every year (called “firm yield”), we need 72,000 acre-feet of water stored in Gross Reservoir. It’s like a savings account for drought years. An additional 72,000 acre-feet of water in storage at an enlarged Gross Reservoir would supply Denver Water customers with 18,000 acre-feet of new supply each year over a four-year drought period. That’s called the “storage to yield” ratio, which is 4:1 at Gross Reservoir.
