ANAHEIM — Holding a nationally televised personal watercraft competition in a river in the middle of August seems like a natural--except when you're talking about the normally dry Santa Ana River, where summertime recreation is usually limited to the bike and horse trails lining its banks.
But a dramatic metamorphosis of the riverbed is taking place. Crews have started building two temporary dams that will enable them to fill a 1,000-foot-long portion of the river with about 15 million gallons of water.
All of this is being done for Jet Jam '96, a sports and entertainment festival that begins Aug. 16 in front of the Anaheim Pond arena.
The river is a flood-control channel that is dry except during heavy winter rains. The portion of the riverbed being used for the event consists of sand and rock. Other portions of the riverbed are concrete.
The idea of temporarily filling a part of the river has been daunting.
"Logistically, it's been a challenge every step of the way," said Pond spokesman John Nicoletti.
It will take about five days to complete the dams, which will be built with existing sand and rock from the riverbed. Crews will then lay and seal a plastic material on the bottom and all four sides of the temporary basin.
This process is expected to be completed Friday. If all goes well, water will then be pumped in from Anaheim and Orange, said Ric Miller, president of event organizer United Sports Entertainment.
When completed, the competition area will be 1,000 feet long, 360 feet wide and 2 to 12 feet deep. The water will be purified and recycled after the event, said Martin G. Higby, associate manager of the Orange County Water District.
"Just as a precaution, we'll be monitoring the pre-event and post-event water. If there is nothing in it that is of concern, it will be pumped into our [storage] basin a half-mile away," Higby said.
The county will also have to temporarily reroute bicycle and equestrian trails because of the event.
Not everyone is enthusiastic about the festival, including Gordon LaBedz, a founding member of the Surfrider Foundation, an international nonprofit environmental organization based in Orange County.
"Water is so cheap, and because of that, it is so wasted," LaBedz said. "If we paid for water what it's worth, we wouldn't use it for things like this."
LaBedz also expressed concern over pollutants in the Santa Ana River that run into the ocean.
"We're real worried about that river," he said. "We'd like to see it as natural as possible. But instead, it is used just as a flood-control channel to bring water to the ocean. It would be nice if it would also bring sand, clean water and provide wildlife habitat."
The Santa Ana River winds 75 miles through Orange, Riverside and San Bernardino counties and poses the largest flood threat west of the Mississippi River, according to the Army Corps of Engineers.
Although the Santa Ana isn't much of a river most of the year, it has overflowed several times in the county's history during heavy storms, causing major flooding.
The $1.3-billion Santa Ana River Project, designed to prevent catastrophic flooding, is scheduled to be completed in 2001. The river has already been rechanneled away from freeways and houses, removing curves and waterfalls that naturally slow water flow.
Before any event preparations could begin, organizers had to gain approval from hundreds of agencies. Complicating matters was the fact that the portion of the river they will use is on land controlled by a variety of agencies.
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A River Runs Through It
Bringing Jet Jam '96 to the Santa Ana River, adjacent to the Pond of Anaheim, requires some adjustments. The riverbed is dry now, but by the time the weekend of competition (featuring Jet Skis and other personal watercraft) and exhibitions is ready to begin, an artificial lake will have materialized. Here's how it will happen:
1) Sand and rock bulldozed to create two levees, each about 18 feet tall
2) River bottom and walls covered with heavy-gauge mesh
3) Heavy plastic liner placed over mesh
4) With Sandbags holding seams in place, 15 million gallons of water added
JET JAM RIVER COMPLEX
Alongside the personal watercraft competition, there will be 300 exhibits and displays, also:
* Hot car contest
* Boat show
* In-line skating contest
The Extreme Zone
Activities on south side of riverbed include:
* Rock climbing
* Reverse bungee jumping
Note: Drawing not to scale
Sources: Ogden Facility Management, United Sports Entertainment and Atherton Communications, LP
Researched by APRIL JACKSON / Los Angeles Times