SUPERIOR — Boulder County smarted from sluggish sales-tax growth and high commercial real-estate vacancy rates in 1991 because of continuing turmoil in its high-tech sector. However, the county’s residential real-estate market was waking from a five-year slumber.

On a stretch of prairie southwest of tiny Superior, construction began on a massive residential development called Rock Creek. Originally selling for $130,000 and up, its houses were considered affordable for the county.

Many dismayed county residents and elected officials saw plain beige development on hills that once had afforded a rolling green foreground for the Flatirons. If everyone was so against it, why did it happen? Water.

Before Rock Creek, Superior had a population of 250 and had run out of water. Its wells were drying up. In the 1970s, the town hooked up to neighboring Louisville’s sewer system when Superior’s septic tanks began polluting its own wells. By the mid-1980s, residents were desperate. Without water, they couldn’t live in their homes — or sell them.

Superior’s trustees went to other municipalities in the county to buy a permanent water system, but no deals were in the offing.

Enter Carlson Associates. The Denver-based developers had been eyeing locations in the north metro area for a large mixed-use planned community. The Carlsons bought land east of McCaslin Boulevard — acreage designated on Boulder County’s master plan as open space — and offered it first to the county, which wanted it but couldn’t afford it.

The Carlsons then shopped the property to adjacent municipalities. Annexation would have to happen before development could occur. Broomfield wasn’t interested but Superior was. Town trustees said they would annex the land on which Rock Creek would emerge if the Carlsons brought water taps from their property into the original town. But, they said, the deal would have to go to a vote of residents. When the vote came, it was 104-6 to confirm the trustees’ action.

Carlson got its annexation, then sold the property to Denver-based Richmond Homes for about $13 million. Richmond got to build its hugely successful residential development; the original town of Superior got $1 million from Richmond for water taps, a new town hall and parks; and the county got an infusion of affordable housing.