Los Angeles' water landscape is a tricky subject, one wrought with both uncertainty and a history of grave destruction.
For anyone living or driving around Southern California today, vast empty dams and drainage channels are an all too common site - one that has even come to define our landscape in films and history. You may wonder why there is so much cement channeling often non-existent water flows when we are plunged deeply in drought crisis. Particularly when the Santa Ana river channel alone daily pushes enough fresh water out to sea to supply the entire city of Long Beach.
Southern California's unique weather and flooding cycle is to blame. Our water landscape has been substantially over-controlled in order to be on guard for large rain surges that visit our region every 40 years or so. Historically our 3 rivers - the Los Angeles, San Gabriel & Santa Ana - were wide and shallow watercourses that ran nearly perennially, though they often flowed down to only a trickle at the end of the dry season. Because they ran so shallow and the surrounding landscape was largely level, their courses changed often, causing problems for early developers and farmers suffering property damage.
This was particularly true when the 40 or [even larger] 100 year down pour cycles came to pass and entire settlements were wiped out (due to poor siting choices in this humble designer's opinion). Historically these 100-year rain events would even swell the rivers so large that all 3 would join and form one vast shallow lake across a great swath of today's North Orange County. Anyone whose ever driven in the region during a major downpour can relate as the streets quickly flood and - particularly in Anaheim & Buena Park - are turned to 2-3' deep rivers.
And so, we can begin to understand how massive military-industrial style infrastructure projects began to be dreamed up and installed all over Southern California. Farm land in the OC was good when it wasn't flooded and planners were tired of seeing their buildings wiped out. The 20th century saw dam after dam and drainage channel engineered and installed. The Los Angeles river was filled with some 750 million tons of cement and, in 2006, a final San Gabriel river dam was installed that boasted being able to handle the region's 100 year cycle storm surges making Southern California officially flood-risk free.
Luckily, as a lifetime of drought continues to plague SoCal, an understanding is slowly starting to build that paving may not be the best course for waterways. Though it protects us from bi-century rain surges, it seriously hampers our region's ability to harvest water from less substantial ones. While we suffer from low local water reserves, the rains that would historically fill our region's aquifers are diverted directly out to sea with no chance for catchment or landscape absorption thanks to the low soil surface area of industrially straightened and fully paved watercourses. Los Angeles is finally realizing that water and natural water features are valuable assets and has committed $1 billion to its river revitalization project, the re-development was recently awarded to "starchitect" Frank Gerry.
While we patiently wait for urban planning to re-visit and renovate it's single-minded water management policies, it's up to us local home owners to also play our own part in increasing local water catchment. This means directing rain fall and grey water into our gardens instead of into sewers. This can be done by increasing contouring in the landscape and planting deep rooted plants that help break up hard pan and allow water to infiltrate all the way down to aquifer level. Let's hope that 100 years from now all three of SoCal's rivers are re-naturalized and once again breathtaking sights (instead of eye sores) to be beheld.
Did you know?
It wasn't until 2013 that the Los Angeles river was actually officially labelled a river again and opened for recreation? Up until that point is was deemed to be exclusively a drainage channel by city planning and considered largely off-limits to the public.
Hi! I'm Briana, Lead Designer and Founder of Califia ECOdesigns in Pasadena, CA. I've organic farmed all over Western North & Central America and love designing drought tolerant and sustainable landscapes. I earned my Permaculture Design Certification in 2011 from engineer Rob Avis.