When the grid goes down, how does a water company keep 36 water towers full? For Rathbun Regional Water Association (RRWA), a provider of water to southeast Iowa, KOHLER standby power kicks in. “Our two KOHLER backup generators — one at the caisson pump building that brings in our raw water and the other at our treatment plant — take over so we can keep processing water,” says Rod Witt, RRWA in Centerville, Iowa. “And the KOHLER units get the job done; no worries there. But without power throughout our distribution area, we’re facing a bigger challenge: we have 36 water towers that need pumping power to replenish levels.”
As Witt describes it, water towers aren’t very complicated; they’re just elevated places to store water that is ready for delivery. In fact, once water is in a tower, it’s as good as delivered because almost all water flows to customers – residences, farms, factories and schools – by gravity.
“When power is lost, the water from a tower keeps flowing,” says Witt, “but a clock starts ticking on how soon each tower will run out. Some towers last a day or longer; others need to be replenished in just a few hours.”
So when the grid flickers off, an emergency plan is initiated in the high-tech Rathbun control room. As Witt puts it: “We essentially have 36 different countdown clocks, one for each water tower, based on water levels and projected usage. It’s kind of like an action picture that plays out in slow motion.”
Rathbun’s 36 towers are spread over 140 miles of rural countryside and connected by nearly 6500 miles of pipeline. How do they keep those towers full? With towable generators from Kohler Power Systems. Each of the four towables is moved strategically among 39 pump stations throughout the Rathbun distribution area. They run for a few hours to top off a water tower, then they are hustled on to the next pump station.