FEDERAL HEIGHTS - Children scream with delight as the gigantic wave rolls across Water World's Thunder Bay, swallowing everything in its path. After the wave crashes on the shore of the pool, park-goers reclaim their scattered tubes and eagerly await the arrival of the next wave.

Hotter temperatures mean more park visitors, but the stifling heat also increase water's value as a precious commodity that can, literally, vanish into thin air.

It takes about four million gallons at any one time to run the park's 42 attractions, which is enough water to supply 10,000 households for a day. Thunder Bay, the football field-sized wave pool, uses 1.8 million gallons of water.

It is no wonder the park utilizes every last drop.

"We are a leader in the water park industry because of our water conservation efforts," said Joann Saitta, communications director for the Hyland Hills park and recreation district.

There are no national trends or guidelines for water conservation in the water park industry because of the differing climates where water parks exist, said Rick Root, president of the World Waterpark Association, a nonprofit organization based out of Kansas whose purpose is to further safety and profitability in the water park industry.

However, "Water World is one of the most well-regarded parks in the country in terms of the number of the things they've done over the years to conserve water," Root said.

During the summer of 2002, Water World started stopped serving their fountain drinks over ice and switched to bottled beverages, a change that saved the park 15,000 gallons of water per season, Saitta said.

The method the park has for saving water include "splash guards" in place on many of the rides to keep water from escaping, pool covers to prevent evaporation and a computerized landscaping system that measures if an area has received enough precipitation through rainfall -- and waters only if necessary.

"Water is our business, we are proud to say we are careful with the usage," Saitta said.

During training, Water World employees are taught to have healthy respect for water, such as not to leave hoses running, Saitta said.

Andy Larington, a maintenance specialist, said he has seen Water World step up its efforts to conserve water over the last 10 years.

"Before, if there was a leak we would get to it when we could, now it is a priority," he said. "A small leak can lose a lot of water."

Larington started working at Water World when he was 14 as a grounds-sweeper. Every summer after that he worked as a lifeguard, then went on to work in maintenance.

Maintenance inspects the park's nine filtration rooms daily, where water is continuously re-circulated, filtered and pumped to the pools and rides. The equipment is examined first for safety, but then to insure no water is being lost.

Water that cannot be sent back to the pools and rides, such as the water used to clean filters, is sent to a holding tank. Then it is treated and pumped to an irrigation pond, which is used to irrigate not only Water World, but other Hyland Hills parks as well.

During his time at Water World, Larington said he has gained an understanding of how important it is to conserve water.

"It is our No. 1 resource," he said. "Little steps end up creating large effects."