During last week’s heavy rainfall, street flooding occurred when newly installed aluminum grates on Pacific Palisades storm drains failed to open. Leaves and debris piled against the grates and caused rainwater to pool in the streets. The grates, installed here last fall at an average cost of $1,200 per grate and paid for through Prop. O funds, are supposed to prevent anything larger than three-fourths from entering the drains during dry weather or light rains. During rainstorms the grates are supposed to swing open, allowing all runoff to enter the drain. Routine street sweeping is supposed to ensure that the grates remain clear of debris year-round. (Street sweeping in the Palisades occurs every four to six weeks, according to Richard Lee, Department of Public Works information officer.) ‘The new storm-drain grates that were installed professionally, and at a considerable expense, are completely blocking the drains and flooding the streets,’ Maxine Greenspan said by e-mail to the Palisadian-Post last Thursday. ‘I have dug out all the debris on the Napoli Drive, Channel Road and Mesa Road drains. There is a terrible design flaw.’   After contacting five different city agencies and not getting a response, Greenspan paid her handyman $50 to kick the grates open in order to prevent flooding. On Tuesday this week, Greenspan reported that ‘After all my calls, the city came out and totally removed the storm-drain screens from in front of my house. Now the water flows freely and is not flooding. [However], it will flood where the screens still are.’   A January 22 letter to the L.A. Daily News from reader Matthew Schaaf of Granada Hills commented, ‘Who was the genius who installed screens over the storm drains? While driving around Wednesday, there were numerous flooded streets caused by leaves and debris clogging the drains. Perhaps our traveling mayor can make sure there are crews to keep them clean when it rains?’   Haldis Toppel, president of the Marquez Knolls Property Owners Association, wrote on January 23: ‘The gridded storm drains got clogged with leaves and therefore most of them did not release to open. Some intersections had massive amounts of water running through them but the water eventually found its way into an un-gridded storm drain. Residents on Enchanted Way, where the deepest flooding occurred, propped the grid open.’   The Post contacted the L.A. City Stormwater Hotline (800) 974-9794; although the city clerk did not wish to give his name, he said ‘The screens are counterweighted and supposed to open up with any kind of resistance.’   Unlike Greenspan’s handyman who kicked the grates open, this reporter tried kicking and opened only three of eight grates along Bestor Boulevard and Swarthmore Avenue.   Michele Vargas, spokesperson for Public Works, said the screens (grates) were approved by the County of L.A. Department of Public Works, which plans to retrofit all 48,180 City storm drains by 2011 (currently about half are done). The total budget for the screens and 10,000 catch-basin inserts is $71.5 million.   The installation of the screens is part of the City’s effort to comply with a state mandate that requires Los Angeles to reduce the amount of trash that goes through storm drains and out to the ocean by 10 percent each year.   Vargas told the Post that in order for the screens to open, the locking mechanism behind the face of the screen needs to be disengaged. Once the grate opens, water flow keeps it inward. When the water recedes, the lock is engaged once again. Vegas said that during a storm the lock will cycle between the lock-and-unlock phase several time; at all other times the screen should be in a locked position. ‘The locking mechanism is triggered by flow entering from either the face of the screen or the overflow,’ Vargas said. ‘The screens have been designed with an overflow on top to allow flow to enter in the event large debris/leaves block the screen face.’ According to Vargas, in preparation for a rain event, the City of Los Angeles Bureau of Sanitation clears all catch basins and debris basins to ensure proper flow of stormwater. If residents observe that catch-basin grates (screens) are not opening during a rain event, they need to call 3-1-1 immediately to report it and City officials will deploy crews to investigate and fix the problem.
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