Record snow pack and rainfall have caused dangerous conditions in Central Valley waterways.

More boaters have died in swift water river accidents in the first six months of 2011 than any other comparable period on record, according to the State of California Department of Boating and Waterways (DBW).

U.S. Army Corps of Engineers Sacramento District park rangers are stepping up water safety outreach efforts for the holiday weekend, as the Valley continues to see more hazardous water conditions than usual.

"We have already seen that this year is more dangerous than most," said Col. Bill Leady, commander of the Sacramento District. "We’re still so early in the recreation season; we want to make sure we’re doing everything we can to let people know what the risks are out there, so everyone can enjoy their summer on the water."

Record snow pack and rainfall throughout the Sierra Nevada this year mean water is running colder, faster and higher in California’s rivers. With water temperatures being extremely cold, outdoor enthusiasts can become incapacitated in just 10 minutes, to the point that the muscles in their limbs stop working and they will no longer be able to swim or rescue themselves, said the DBW.

"This weekend is supposed to be very hot, and the reservoirs are a great place to cool off, have fun and relax during the holiday weekend," said Jonathan Friedman, senior park ranger for the Sacramento District. "Just be smart and safe about it. Plan ahead and always wear a life jacket," he added.

Corps rangers are spending additional hours on boat-patrol, handing out copies of boating rules and educational materials, and working with local law enforcement to make sure visitors are safe and informed of the risks.

“Outdoor enthusiasts in, on and around the water must use caution and be prepared,” stated DBW’s Acting Director Lucia Becerra. “Many rivers will be running faster and higher this 4th of July weekend than in the past years. Water levels in lakes will also be higher, masking underwater hazards that were exposed in previous years.”

The biggest safety concern now is the use of flotation devices such as lightweight rafts which may be designed for swimming pools or calm waters. These flotation devices are dangerous. They can easily lose air or be punctured by debris or tree branches. Use of these types of devices is strongly discouraged during this period of high, swift and cold water conditions.

Knowing what to do in case of a water immersion, understanding the effects of cold water and wearing a life jacket are critical in improving chances of survival.

"Before you go out this weekend, check local water and weather conditions and heed recreation warnings like river closures from local emergency services offices," Leady said. "But the single most important thing you can do on the water to protect yourself is to wear a life jacket."

The Sacramento District manages 10 parks and lakes in California. The U.S. Army Corps of Engineers is America’s largest federal provider of outdoor recreation, serving more than 370 million visitors a year at 422 recreation parks in 43 states.