City to begin annual installation of dams

During the next two weeks, city crews will install dams in eight of

the city’s storm drains and flood control channels to divert urban runoff

during the spring and summer into the county’s water treatment plant in

an effort to prevent pollutants from reaching the ocean.

Of the eight storm drains, two will have permanent dams built in them

while the remaining six will house temporary blocks, said John Pietig,

Laguna Beach’s assistant city manager.

The temporary dams will be removed in October.

“For years past we’ve put [dams] in during mid-April, this week and

next week, and they stay in until mid- to late October and sometimes

[longer],” Pietig said.

Crews will also install five additional treatment and diversion

systems in the coming months that will either allow dry season urban

runoff to flow into the city’s sewer system during the summer months, or

make sure runoff stays in the storm drains when it rains, said Steve May,

the city’s director of public works.

Construction of the five systems may begin in three months, May added.

Each of the five systems costs between $80,000 and $100,000, which

will be paid partly from federal grants for transportation improvement

and capital improvements, May said.

Runoff from residents watering their lawns or from fertilizers

draining down a hillside will be directed into the city’s sewer system

and then be pumped with the rest of the sewage into the coastal treatment

plant.

“This prevents pollution from reaching the ocean, causing beach

closures,” Pietig said.

Both the size and material making up a dam vary. The largest dam is 10

feet in diameter inside a channel near City Hall, while others cover 4-

to 6-inch pipes, Pietig said.

Permanent dams are made out of concrete. Temporary dams include

materials from railroad ties to plywood, he added.

The city has more than 50 storm drain outlets.