When Good Intentions Create Hazards - Storm Drain Flooding

Subtitle:  City Officials Plug Storm Drains - Puzzled by Flooding

Recent rains in the Los Angeles (California) area made the news because of street flooding, cars stranded, and people in peril from the flood waters.   What did not make the news, though, is a decision that was made some time ago that stops up the storm drains at the streets.  The streets flood because the water has no place to go.   See photo at right.

Street curb storm drain inlet with hinged debris barrier
in Los Angeles, CA photo by Roger Sowell

  

The debris barrier is a perforated, horizontal metal plate that is hinged at the top, and spring-loaded to remain closed.   The plate is to swing inward from the bottom when water pushes against the plate.   Debris is to be caught by the barrier and removed so that the storm drain piping system underground is not blocked.   At least, that is the theory.  In practice, the debris barrier shown in the photo was frozen shut.   The hinges did not allow the plate to move.   Only after a few strong kicks was a worker able to make the debris barrier move.  Even then, the spring tension was quite high for the intended purpose.  It is doubtful that the force from a few inches of water would overcome the spring tension and hold open the grate.   (I personally pushed the debris barrier to determine for myself how strong was the spring tension.)

So, in effect, Los Angeles has installed drain stoppers in thousands of locations.   This, just in time for the El Niño rains.   A recent news article (see link) describes the flooding in an area of Los Angeles, the San Fernando Valley (aka The Valley).  

Sometimes one has to stop and wonder at the actions of government.  Surely, there were good intentions behind the installation of thousands of debris barriers.  After all, it is a good idea to prevent sticks and trash from entering the storm drains since those can block or partially block the flow.   Ideally, only the rain goes down the drains.  However, one must also wonder if the city's decision-makers talked to any engineers about the negative effects of the debris barriers.   These are mechanical devices, relying on a plate that rotates about a hinge.  They are in an outdoor location, subject to the elements.   Even if they don't rust, they still will have dust, grit, grime, moisture, collect on the hinged areas.  The grit will grow in layer upon layer, until the force required to swing open the barrier is just too great for any water flow.  

There was substantial flooding in some areas in the last round of rains, about one week ago (January 5 and 6, 2016).   One news story showed a city worker in water up to his waist, using his feet to clear a clogged storm drain in the suburb of Sun Valley.   One can only imagine the difficulty in kicking open that debris barrier while standing in 3 feet of water.   

I also witnessed a few flooded intersections where I drive in my daily routines, on the same dates.  Having lived in the area for 30 years, I can say that those intersections never flooded before.   I did not stop to feel around on the storm drains in the rain, but it is quite apparent now that the rains have stopped that those intersections also have the drain plugs - excuse me, the debris barriers.  

Roger E. Sowell, Esq.
Marina del Rey, California
copyright (c) 2016 by Roger Sowell, all rights reserved

Hurricane Dolores in Los Angeles

A post from 2009 on SLB (see link)  titled Hurricanes in Los Angeles was critical of public officials in their warnings and evacuation plans ahead of that hurricane.  Of course, hurricanes almost never hit Los Angeles because the ocean surface temperature offshore Southern California is far too cold to sustain a hurricane. 

Today, however, the remnants of Hurricane Dolores 2015 sit offshore Los Angeles, and moisture from the storm's arms is turning into rain, creating flash flooding in the regions surrounding Los Angeles. 

From the National Weather Service, the following warning was issued:

AT 550 PM PDT...DOPPLER RADAR INDICATED AREAS OF STRONG AND SLOW MOVING  THUNDERSTORMS PRODUCING HEAVY RAIN ACROSS THE CENTRAL PORTION OF THE SAN GABRIEL MOUNTAINS AND ADJACENT FOOTHILLS OF THE SAN GABRIEL VALLEY ALONG THE INTERSTATE   210 CORRIDOR. VERY HEAVY RAINFALL WITH RATES OVER ONE INCH IN 30 MINUTES HAVE BEEN OBSERVED... CAPABLE OF PRODUCING FLASH FLOODING AND DEBRIS FLOWS. 

Global warming alarmists will almost certainly use the Dolores 2015 event as proof of their theories that man-made carbon-dioxide is heating the atmosphere, and that creates stronger hurricanes, floods, and storms.    Of course, when such alarmists are asked to explain similar events that occurred pre-1970, they alarmists attribute those to natural causes.   It is notable that 28 floods occurred pre-1970 according to a document published by State of California Department of Water Resources (see link) titled "History of California Flooding (2013), Table C-1"  Of the 28 floods, 3 were from tsunamis, and 3 were from failed dams, leaving 22 from rain events.   Those 22 are not all of the floods pre-1970, only the major floods. 

Sometimes it seems that the warmists simply do not understand that history did not start in 1970.   Hurricanes, floods, droughts, severe winters, heat waves, volcanoes, earthquakes and tsunamis all happened before 1970.  There were changes in local temperature, also.  

Sometimes, but rarely in my experience, a rational warmist will discuss such events.  Their response usually is along the lines of "we do not dispute the existence of severe weather events before 1970, only the severity and frequency.  Since 1970, man-made CO2 in the atmosphere has made the severity greater and increased the frequency of such events."  

Even that statement is full of problems, since some of the floods (8 of the pre-1970) were statewide in scope.  It is difficult to imagine greater severity.   The response to showing the warmists actual data is usually along the lines of "you are only considering a small part of the Earth's surface, California is far less than 1 percent of the globe.  We consider the entire globe, hence Global Warming."    When such statements are made by warmists, be sure to ask them to provide the data for your inspection.  Note whether the data is from authoritative sources, or from agenda-driven ideologues. Also note whether the data is truly global in scope, or skips over parts of the Earth where the data do not fit their agenda.  

Finally, it is always fun to ask warmists how the severe and prolonged cold weather events continue to occur, 45 years since 1970 and with CO2 levels now at 400 ppm.  Note that ice is more persistent on the US Great Lakes, Great Lakes' water temperature is colder than historic averages, ice and snow are more intense in many areas, and many glaciers are growing. 

Roger E. Sowell, Esq. 
Marina del Rey, California

copyright (c) 2015 by Roger Sowell.  All rights reserved.