Meandering Floodplains provide Real World Biomimetic Blueprints for Infrastructure Designs vrs Engineering Inspireded by Ambitious Human Business Venture Schemes
|Image - ourwellnessway.com|
The iconic classic movie, Chinatown, makes it abundantly clear that humans have always disrespected designs found in Nature, especially when their wouldview (based on blind faith) believes that such designs are an impedement to their economic business successes. This is certainly true with the history of Los Angeles where business development and growth hinged on aquisition of water, both it's abundance and controling it. LA’s legendary water superintendent William Mulholland was driven towards channeling this water from the Owens Valley to Los Angeles. But stealing water from far away north wasn't enough. Vast floodplains in Southern California had potential economic value for both agriculture and the creation of an industrial infrastructure. So the natural meandering physics of flowing water on floodplains had to be tamed and harnessed. Take for example this photograph above with the meandering switchback pattern of the river. From a politics and businessman perspective, this impedes quick transportation of both people or goods. Logically (from a flawed human perspective) a straight channel direct line would seem to be the obvious choice. Same logic for getting rid of stormwater quickly from cities to prevent flooding, straight channeling seems the better choice. This is evident by all the straight floodcontrol channel infrastructure you can find throughout all of Southern California like the Los Angeles River below. Unfortunately, the path of least resistance hasn't always been the safest or most efficient route for moving human economic goals forward.
|Photographed by Lane Barden|
Industrial corridor of the Los Angeles River at the
Seventh Street bridge in downtown Los Angeles, California
|Image - Nature Conservancy - Stream Restoration|
|Institute of ecological Technology|
|Very crudely designed log flume|
|Illustration - giewasser.ch|
|Image - LifinLapland.com - Nellim Log Flume|
While the early history of true biomimetics regarding hydrology is interesting, how does any of this benefit the average person today, especially in view of the further degradation of our planet's natural world that has been accelerated through the misuse and abuse of science ??? While there are some who truly believe in biomimicry of Nature, they are still greatly outnumbered by those who would trash Nature through the worldview argument of Nature being badly designed and only intelligent free-thinking humans can fix those flaws through scientific shortcuts. Okay, so change of pace here. There is an organization whose mission is to revitalize the contrete channelized L.A. River bed. who are known as the "Friends of the L.A. River". That's a tough assignment they've given themselves. Even during the lightest rainstorms, the greater L.A. infrastructure is human designed & engineered to rapidly facilitate storm water off the streets, parking areas, rooftops etc and efficiently send it rapidly on it's way down to the Pacific Ocean. This is an incredible waste of valuable freshwater resources. But believe it or not there are viable real world natural solutions to reduce runoff and redirect water into public and private landscapes and possibly percolate much of in into the subsoil layers of the ancient floodplains to be used later as well water. How much depends really on people being interested in change for the better. Below I'll provide a gallery of photos demonstrating how street rainwater harvesting techniques through biomimetics can change the present Hydraulic infrastructure and save disappearing fresh water resources from the outside of the region. Take a look, much of where this is already practiced is from areas with higher rainfall averages than Southern California like up north and back east.
Large City Street Landscaped Medians
|Image - svrdesign.com|
This is the central California city of Paso Robles, who are successfully positioning themselves at the leading edge of this municipal rainwater harvesting technology which biomimic's nature by the use of "baffles" which creates a switch back motion replicating the meandering pattern in the design & using periodic low dams called weirs (replicates beaver dams on small scale) which deliberately slows & backs up water raising the water level behind the weir in the planting bed that allows a good percentage of water to percolate deeper into deeper subsoil layers. Top photo illustrate what happens during storms and lower photo reveals an attractive look when dry. Utilizing native plants and having knowledge of how to encourage one gallon containerized seedlings to develop deeper root systems would truly help such plants make it without any further water assistence the rest of the year. There could be a minimal irrigation infrastructure of deep irrigation designs, which would be utilized only in emergency summer situations to supplement and apply water three or four foot below the soil surface where most healthy California native plants want and prefer it.
|Image - svrdesign.com|
Here in this picture above you can see the baffles which look to be recycled small guage railway track with a center concrete guide on top of a bed of cobblestones which allows the waters to slow down and remain clean prior to easing into the actual planting beds. Further cobblestones downstream are both functional for keeping soil intact, allowing further percolation and have a decorative purpose that biomimics a dry streambed which are common in California.
|Image - hawkinspartners.com|
Curb and Gutter Rainwater Harvesting for Landscapes in Business Areas and Residential Main Streets
|Image - State Collage Pensylvania|
Curb cut-out inlet to rain garden on west side of Allen Street near Pennsylvania State College. Just like a forest with meandering water courses and beaver dams, the goal here would not be to prevent water from reaching the oceans, but slow it way way down and make it work for the benefit of all sorts life along the way down.
|Image - State Collage Pennsylvania|
This rain garden is demonstrating weir flow during rain event. For those who may not understand what the word "weir" means. The term "weir" is a Dam-like barrier across the horizontal width of a landscape bed that alters the flow characteristics of the water and usually results in a change in the vertical height of the water level. There are many designs of weir, but commonly water flows freely over the top of the weir crest before cascading down to a lower level section of the landscape bed. Again, the purpose here is not to prevent water movement down stream, but rather to slow water movement down and percolation with drainage at the end for major storm runoff.
|Image - State Collage Pennsylvania|
Now here is the full entire length-wise view of rain garden on west side of this Allen Street. Everything here is functional and decorative all at the same time. The concrete weirs again back the water up in a small pond behind the artificially replicated beaver dam. With a series of weirs, this would also prevent erosion of planting bed materials just the way a series of beavers dams would accomplish on a real life floodplain in the wild.
Residential Neighbourhoods and other low Traffic Side Streets
|Image - progress-project.eu|
|Image - greywateraction.org|
Sidewalk bioswale treats street runoff in Portland, Oregon
In cities like San Francisco California and Portland Oregon, their storm drains are connected to their sewer treatment plants, and the potential for hazard for such infrastructure design is that heavy rains cause the sewer plant to overflow with raw and partially treated sewer water into the bay or river. Other cities connect their storm drains to underground creeks, and the polluted oily water runs straight into the bay or nearby river. By cutting curbs and digging sunken basins into the “right-of way” or “parking strip” area of the sidewalk, you can turn street rainwater from a problem into an actual resource. Diverted rainwaer that falls on streets can nourish plants, protect creeks, and contribute to cleaner cities as a result of the planter bed's healthy microbial community taking care of the pollutants & turning them into safer elements.
|Image - svrdesign.com|
Preventing and reducing water pollution can be as simple as building a rain harvesting curb cut for the garden. Once again, this runoff water from streets can come in contact with various substances to pollute it like chemicals from fertilizer, oil from cars and garbage, etc. Before this polluted water makes its way into storm drains and our riparian ecosystems, we would filter it through a natural rain collecting garden with a strong healthy microbial soil community to digest & process it. Rain gardens can also add to a home’s curb appeal and allow runoff water to filter naturally and deeply down through your yard’s soil. Keep in mind also that many of these structure as also designed with outlets and/or drains into runoff water pipes to allow for those extreme weather downpour events.
Commercial Parking Lot Medians and Dividers
|Image - landskapsarkitektur.no|
What amazes me with many of the beautifully designed landscape medians in many places like these parking lots is the fact that they exist in mainly higher rainfall areas like the northern & eastern parts of the USA, Canada and Europe, like this example above in Norway. What about Southern California where it is even more needed because they lack water ? Free water that is otherwise facilitated rapidly down the drain so that they basically are forcing themselves to use public utility provided clean drinking water to irrigate their commercial and home landscapes.
|Bioswale parking lot created by Lynn Capouya Landscape Architecture|
This is the kind of thing that really makes sense. Love the plant selection for the area and keep in mind that mulch is an important part of this bioretention system to really work effectively. Rocks and other smaller cobblestones are perfect for the slowing down of water movement and work perfectly as a mulch to keep the ground cool and retain moisture levels in soils. This is extremely important in parking lots where they create a massive heat islands.
|Image - grownative.org|
These Natives plants within the planter accompanied by a species abundant microbial community within the soil system are able to filter the runoff and protect streams. They can recycle the pollutants & turn them into nutrients that the plants can use. No stream or river pollution to kill aquatic critters in the water environment. Also runoff volume is greatly reduced (not stopped) which prevents the violent scouring of the natural local creek or riverbeds which allows the system to be stable, much like it was prior to human pavement. I would love to do something like this picture (minus the parking lot) for my mother's property with street curb back in El Cajon California. Unfortunately I'd have to be living back there permanently to maintain it. However having said that, look below at this Walmart parking lot in Santee California.
|Image - Google Earth|
Walmart parking lot in Santee California
Last year in May/June 2016, my wife and I went back to my home town area of San Diego California and visited my mother who lives in the El Cajon/Santee area. Ignore the 2017 dates on the Google Earth picture, I just posted this to illustrate how illustrative it is of ir's improper design when they took this parking lot photograph. When we visited this exact parking lot (May 2016), it was 100+ F (40+ C) and I waited in the car while mum and wife went shopping. Half of those trees, irrigated by inefficient bubblers in a tiny planter median were dead or dying because they stopped watering them. Why did they cut back the water ? Because prices out there are outrageous, even when people have cut way back on watering like they were asked to in order to help buffer the shortages create by drought, the Water agency went and raised the water rates big time. Hence, the management decided the landscape was not worth the effort and expense. so the parking is nothing more than functional in purpose. Too bad and every customer who visits fights for that small shady spot for their car because of the effect of direct sun in 100+ degrees pushes inside temps 160+ degrees.
The Landscape median mechanism designs for Successful Water Harvesting
|Image - Empowerhouse|
These are just some simplified animated illustrations to help provide an easy way to comprehend the design of the soil system withing the planter. Water enters into the cells through curb cuts and flows to an area planted with native plants (preferably native to the region that are attractive and ornamental looking) & a microbial community system that are known to remediate heavy metals and toxins that vehicles usually leach on to the street, not to mention the totally unnecessary Agro-Chemical products used by commercial & home owner landscapers. The water is filtered through the topsoil where most of the roots are and then into a type of mixed gravel bed which will hold and store the bulk of the floodwater only then to seep slowly back into the subsoil layers and possibly as far as the moist ground water supply which helps to alleviate runoff to local waterways. Usually this rain water runoff would enter directly into the storm system, where it could lead to an increase in combined Sewer Overflows that contribute significantly to the pollution in our rivers and streams.
|(Image courtesy of GeoSyntec Consultants)|
Stormwater runoff flows into this type of bioretention area like the other one above, percolates through the soil (which acts as that bio- filter) and eventually drains into the groundwater; some of the water is also absorbed by the plants. Bioretention areas are usually designed to allow ponded water and with an overflow outlet to prevent flooding during larger storm events which are becoming more common. Where soils have low permeability or where faster drainage is desired, designers may incorporate a perforated underdrain that routes to a storm drain system. If you have a soil profile like my mother's place which is built on top of an ancient alluvial floodplain, then such drains may not be necessary. But if you have a clay or adobe type soil profile, then I'd recommend the drainage.
Nice Video Resources
This video surprisingly comes from the State of California. I say it's a surprise because you cannot see very much in the way of people practicing this water harvesting technique out there, with the exception of the Palm Springs & Coachella Valley areas.
This video below is excellent as it provides a how to for boring a hole through the curb and sidewalk to allow a inlet for stormwater to enter into the landscape strip.
This final link comes from Arizona. Actually it is a separate post I created because Arizona is much further along on this biomimicry and their climate almost mandates such a practice be done over there. And besides I thought it would have cluttered this post up with more info than it already has. 😏