As Colorado Springs Utilities prepares to embark on the construction of its billion-dollar Southern Delivery Pipeline, it’s worth noting that water usage has declined by nearly a quarter, or 7 billion gallons, from 2001 until 2009.

The reduced demand over the nine-year period is largely a result of customers  using less water on their lawns and gardens, said CSU spokesman Dave Grossman. Rebates on energy-efficient toilets, water restrictions and other factors also played into the tremendous conservation effort,  he said.

In 2001, customers used 30.3 billion gallons; in 2002, 27.4 billion gallons; in 2003, 24.4 gallons; in 2004, 23.5 billion gallons; 2005, 26.1 billion gallons; 2006, 26.2 billion gallons; 2007, 25.4 billion gallons; 2008, 27.5 billion gallons, 2009, 23.6 billion gallons.

The city population grew by roughly 40,000 people during the same period, which suggests that water savings per household was even greater.

Grossman said in the midst of the severe drought in 2002 and 2003, it looked like Utilities needed to bring SDS on as soon as possible and was hoping to have the project completed by 2007.

“However, due to the tremendous conservation efforts by our customers in the years that followed, we’ve been able to delay the need date of the project until 2016,” he said.

“Conservation has enabled us to defer these construction costs (and rate increases) for several years.”

But now the SDS bill is coming due. The muncipally-owned monopoly is set to raise rates by 12 percent annually from 2011 through 2016.

Those hikes will come on top of a nearly 50 percent increase that went into effect in 2009-2010.