While some state and municipal lawmakers are freezing or banning data center construction because of water and energy concerns, others are trying to strike a delicate balance between economic growth and water stewardship.

In Aurora, a Colorado city built on an arid high plain and distant from any major natural water source, city council members yesterday voted 10-0 to prohibit large-scale evaporative cooling in data center designs.

Aurora is currently home to 9 operational data centers, with another 5 in the permitting or land-acquisition process.  The evaporative cooling ban targets unapproved future projects and is not retroactive. It will not affect the QTS data center project near I-70 and E-470 as its expansion bakes in its closed-loop cooling. In fact, the QTS system, which recycles internal liquid and uses less than 1 million gallons of water / year, was the inspiration for the council’s decision.  At full buildout, QTS will utilize between 65 – 80 acres of land and demand 160-177 MW of critical power.  Even though it will scale up water usage as new buildings open, its ongoing daily water demand will remain near zero.

Vantage’s Trident Data Center, which pushed the public debate to a boiling point in Aurora, is set to utilize 143 acres of land for a multi-building campus featuring two data centers at 860,000 square feet and possibly 1.5 million square feet in its final footprint. Because the Trident project is currently sitting in the planning and permitting pipeline, it will be subject to the new law. Vantage frequently builds closed-loop campuses, but may have to alter engineering timelines as a result.

Other regulations may be on the horizon, as Aurora city officials are still assessing issues around setbacks and landscape buffers for data centers in certain areas. But for now, water was the the primary focus, as the city gets 95% of its water from surface sources for which it has to buy water rights (including water basins in Colorado, Arkansas, and South Platte) – with 12 different reservoirs delivering water from up to 150 miles away.

This balanced approach might serve as a prominent model for other water-stressed cities managing severe drought. However, as RCR Tech pointed out recently, a ban on evaporative cooling will likely lead to higher electrical energy usage as fans, pumps, and mechanical compressors will be needed to reject heat.