Twenty years ago, after a 14-year-old boy drowned, Linda Meneken pleaded for more warning signs around the Walnut Creek channel near her home.
"I think there's a lot more that can be done in terms of fencing and barriers, signage," said Meneken.
Today, Meneken is renewing her plea after two more teenagers -- 16-year-old Matthew Miller and 17-year-old Gavin Powell -- died during a rafting expedition on the same stretch of water.
"This is a teachable moment," she said.
Meneken took her message to Contra Costa supervisors who directed staff to identify ways to heighten safety along 72 miles of flood control channels and creeks.
"We can put taller fences in, but if someone wants to get in they may get in, even if you put taller fences in," said Mitch Avalon with Contra Costa County Public Works. "I think maybe a better objective is to have a situation where people understand it's not safe to go in and then they don't want to go in."
In 1991, after 14-year-old Roberto Alvarez died, public works painted red warnings on the cement wall. But in some places, where the waterways run through private property, there may be few signs and no fences.
A large part of the county's public awareness campaign would be to educate the public about the creek's hidden dangers. For instance, a large section of Walnut Creek actually travels underground.
Rosa Alvarez still lives near where her son Ricardo died. There were fences then, but Ricardo found an opening and used a rope ladder to climb down. Alvarez was devastated to hear two more boys had died.
Meneken hopes whatever the county does, it helps prevent another tragedy.
"Hopefully I won't be out here again, hopefully not very soon anyway," said Meneken.