Dangerous Waters

When Matthew Miller, 16, and Gavin Powell, 17, strapped on their helmets and set off in their raft on a waterway in Walnut Creek on Saturday, they didn't realize how dangerous their trek could be.

The creek where they are believed to have cast off is like one of scores of natural waterways that wind down out of the hills and meander through East Bay suburban residential neighborhoods.

The day they decided to go, last Saturday afternoon, came after nearly an inch of rain had fallen in Contra Costa County in the previous 24 hours. The water levels in the creek, which passes to the south of Murwood Elementary School, were higher than usual. 

After cruising about 500 feet down the tributary, the Las Lomas juniors would have passed through a tunnel and dropped down into what's called the San Ramon Creek bypass.

This channel is part of the Contra Costa County flood-control system, which drains water out of Contra Costa County and into Suisun Bay.

It is not known which route Miller and Powell intended to follow or where they ended up in the water out of their two-person inflatable raft, but they were reported missing late Saturday night and found dead Sunday. The cause of death was drowning.

The San Ramon Creek bypass has a concrete bottom and walls as high as 30 feet. Being in this bypass, especially during and after a rain storm, can be extremely dangerous, said Mitch Avalon, the deputy public works director for the Contra Costa Flood Control District. 

"(The flood-control system) is designed to move the water very fast and with a tremendous amount of force," he said. "It'll pull you right down and there's debris, too, so a log from a tree could also hurt you."

These dangerous waterways aren't exclusive to Walnut Creek. They are spread throughout the East Bay and the Bay Area.

With an Arctic cold front bringing more rain, lower temperatures and possible snow flurries lower than 1,000 feet, officials warn others not to repeat what Matt and Gavin attempted.

Avalon added that storms later in the rainy season tend to push more water into creeks and flood-control canals. The ground is saturated from the season's earlier storms, increasing the volume of water.

"It can rise pretty fast in a storm, especially if much of the watershed is saturated from previous rains," Avalon said.

Matt and Gavin, lovers of the outdoors and of adventure, are believed to have left in their raft at 2 p.m. Saturday beneath the bridge where Vanderslice Avenue crosses the tributary and enters the Murwood Elementary School parking lot.

On a calm, sunny day this week, during a break in the storms, the water level in the tributary was higher than usual. But the creek offered a peaceful, benign setting, flowing gently around rocks and along banks covered with grass and trees.

At various points, the water stilled into calm pools no more than 2 feet deep. You could criss-cross the creek several places by stepping from rock to rock. If you happened to fall in, you could pull yourself out.

Under the bridge, some friends of Matt and Given's had written a note: "You were the best people you could ever know. You will never be forgotten and always missed."

Other impromptu memorials hang on a cyclone fence that crosses the bridge.

The setting for the San Ramon Creek bypass is much less bucolic and more forbidding. However, it's clear that people have climbed down into the canal with some frequency.

Elaborate grafitti lines the walls. A resident says that in the summer teens are known to hang out and party in the tunnel through which Matt and Gavin would have passed on their way to the bypass. 

Walnut Creek city officials and local creek experts say that somewhere just north of Murwood Elementary, San Ramon Creek splits. One branch, the original San Ramon Creek, wanders west through the Creekside Drive neighborhood.

This western branch also has been more or less left in its natural state. That is, it looks like a regular creek, with steep grassy banks shaded by shrubs and tall oaks and other trees.

The branch flows right in front of . Some wonder if Matt and Gavin had hoped to follow the original San Ramon Creek and travel past their school. Or even stop their journey there. 

Meanwhile, the branch to the right — the bypass built to prevent winter flooding from San Ramon Creek — enters a dark, mile-long tunnel that carries water under South Broadway. "It's like a box," one official said. 

The bypass is visible again where Newell Avenue crosses South Broadway. It continues along the Ironhorse Trail as it passes behind Safeway and Civic Park.

Near Civic Park, Walnut Creek, formed by the merging of Las Trampas and San Ramon creeks, joins with the bypass, according to Lesley Hunt, president of Friends of the Creek.

The waterway continues north under Ygnacio Valley Road through Walnut Creek Intermediate, with a high fence on both sides, and up through central Contra Costa County. 

This is the waterway in which a 79-year-old man and his 40-year-old son died in April. The Honda they were riding in with a third family member accidentally plunged into the canal where San Miguel Drive intersects Mount Diablo Boulevard.

At the time of the accident, a storm was dumping water in the Bay Area, and the flood channels were swollen. The current carried Jim Hogan and his wife, Janet Hogan, 74, miles north. Their son, Tim Hogan, 40, was trapped in the car and died. 

Unlike a natural creek, flood-control canals, with their tall concrete walls, offer little for a person trapped in the current to grab onto, such as a tree branch, Avalon said.

Janet Hogan, a strong swimmer, managed to keep her head above water before she was plucked out of the canal by rescue workers. Her husband's body was found several days later miles upstream near Buchanan Field airport. 

"There's no way out," Hunt said. 

"There's trees and debris and all kinds of stuff to make it dangerous, especially when the water is high," said Lt. Mark Covington of the Walnut Creek Police Department. 

Fatalities in the channels happen every 20 years or so, Avalon said. Perhaps most memorable was an accident in January 1973, in which two teenage boys, also students at Las Lomas High School, entered the channel near Cherry Lane in Walnut Creek and were found dead downstream in Concord.

Avalon noted that the flood channels have "drop structures." There are 15 along the channel between Walnut Creek and Concord. Some are as high as 10 feet. They act like waterfalls.

The water at the top and bottom of the structures can be very turbulent, he said. People can be seriously hurt if they crash into the concrete pylons at the bottom of the drop strucutres.  Matt and Gavin's raft was found near one of the drop structures at Bancroft Road and Bentley Street, about three miles north of where they started. 

Another example of an extremely dangerous waterway is the Contra Costa Canal, which is maintained by the Contra Costa Water District. The canal stretches from Antioch to Bay Point and down through Concord and Walnut Creek, before going back north to Martinez.

To keep people out, much of the canal is double fenced and patrolled 24 hours a day, said Jennifer Allen, Contra Costa Water District director of public affairs.

She said people almost never go in the canal but do occasionally fish there. When caught, Allen said the fishermen are promptly removed.

"The current is so strong, if you were to fall in there are few places to pull yourself out," she said. "When our maintenance people are out there, they are wearing a floatation device and are tethered to the wall to make sure they have a way out."

An agency overseeing a number of waterways from Pleasanton to Pinole is the East Bay Regional Parks District. Dan McCormick, aquatics manger for the parks, said signs are displayed in areas where people should stay clear of the water.

He said people generally follow the warnings but said there are creek trails in Alameda in which people could be tempted to go in the water. He emphasized that going into flood-control canals is a terrible idea.

"You need certain equipment and training for flood rivers, professional kayakers won't ever go in them," McCormick said. "So just don't do it."

McCormick added that it's not just flood-control waters people should stay out of, but any waterway in which "there is moving water—you don't want to go in."

Contra Costa County officials are trying to determine whether additional fencing or warning signs are needed near where Matt and Gavin gained access to the creek. The Flood Control and Water Conservation District examined the site this week.

Avalon told the San Francisco Chronicle officials will determine whether additional fencing or warnings are necessary or even feasible.

That tributary where the ill-fated raft trip began is accessible to foot traffic on both sides of Vanderslice Avenue. Although a sign, posted on a fence across the Vanderslice Avenue bridge, advises that creek access "is restricted," there is no fence blocking access to the creek on the east side of the bridge. The entire stretch of Kayser Court, a private road, offers creek access.

However, putting up fences around any of the 72 miles of creeks running through Contra Costa County might not be possible or desirable, Hunt said.

While tall fences and warning signs surround flood-control channels, many creeks, such as the one that passes under Vanderslice Avenue, are not totally fenced in—or fenced at all.

These creeks pass through property belonging to special districts, the county and cities. Many creeks also run through private property, and it's up to homeowners whether they want to build a fence on their land.  

"The problem the government faces is do you wall off all the creeks so no one can enjoy them?"asked Hunt, whose group regularly organizes cleanups along their banks. 

Creeks, if not the flood-control channels, are easily accessible throughout Walnut Creek: in front of Las Lomas High, at the Trader Joe's parking lot, where Olympic Boulevard crosses Las Trampas Creek. Homeless encampments have grown up under bridges along the creeks in downtown Walnut Creek. 

Walnut Creek Mayor Cindy Silva supports the idea of various agencies, including the city, county, flood-control district and the sheriff's and fire departments, meeting to discuss ways to prevent such tragedies.

At the same time, she echoed Hunt, saying that more education of youths would be helpful. Youths need to understand that nature is to be enjoyed but must be respected, she said.