Excerpt From: Rainwater Harvesting for Drylands and Beyond: Volume 2,
Brad Lancaster, 2008, 2010.
Thought Seeds
“Don't pray for rain, if you can't take care of what you
get.”
-- R.E.
Dixon (1937) Superintendent, Texas Agricultural Experiment Station, Spur, Texas
As reported by
American Rivers, development and excessive impervious paving in Atlanta,
Georgia and surrounding counties contributes to a yearly loss of rainwater
infiltration ranging from 57 to 133 billion gallons. If managed on site, this
rainwater -- which could support annual household needs of 1.5 to 3.6 million
people -- would filter through the soil to recharge aquifers, and increase
underground flows to replenish rivers, streams, and lakes.
Volume 2
Foreword by Andy Lipkis
As president of TreePeople, a
nonprofit organization I founded 37 years ago, I like to say that we are
helping nature heal our cities. Our work is to inspire people to take personal
responsibility and participate in making their cities sustainable urban
environments. Our prime focus is to support people in designing, planting, and
caring for functioning community forests in every neighborhood in Los Angeles
(at the time of this writing, one of the world’s least sustainable megacities).
Forests are natural sustainability
infrastructure. Trees are THE basic earthwork. Amongst other things, trees and
forests, and the highly porous and mulched soil beneath them, capture, slow,
filter, store, and recycle rainwater, and thereby recharge streams, groundwater
aquifers, and springs. They provide protection from droughts, floods, and
pollution — cleaning the water so it’s drinkable and usable. Trees and forests
sustain life. Unfortunately, when most cities were created, the land’s original
watershed functionality was unwittingly destroyed. The idea behind functioning
community forests is to plant trees and manage the land in cities in a way that
mimics natural forests, bringing water, protection, and resources back to urban
residents. However, since urbanization has
sealed so much of the land with buildings, roads, and parking lots, simply
planting trees and creating green spaces often isn’t enough to make up for the
lost watershed. By adding additional rainwater harvesting technologies that are
designed to mimic nature, such as earthworks — infiltration pits, swales, and
cisterns — it is possible to replace the watershed and ecosystem functions that
were lost.
The magnitude of the water crisis —
and the opportunity — became clear to me in
1992, when the US Army Corps of Engineers proposed to spend half a billion
dollars to increase the capacity of the Los Angeles River by raising the height
of its concrete walls. The Corps determined that the Los Angeles area
had been so overpaved that, instead of soaking into the ground, rainwater from
a 100-year storm event would rush off all the paved and sealed surfaces so
quickly that it would overwhelm the river and flood the nearby cities of
southern L.A. County.
It was at that moment that the “How
Yur Tanks?” [note: he refers to habitual greeting of rural Australians] lessons
clicked for me. I wondered how much of our 14.7 inches (373 mm) of average
annual rainfall we were throwing away each year, and whether we could use that
half billion dollars for cisterns to capture and use that precious rainwater,
just like the Australians.
I asked the county’s flood control
engineers and they dismissed the idea, stating that replacing the river walls
would require installing a 20,000-gallon (75,800-liter) tank at each of one
million homes — an expensive and impossible task. The local water supply and
stormwater quality agencies had similar responses to my questions. The idea was
too expensive for their individual missions and budgets and would require what
they all considered to be completely unacceptable lifestyle changes on the part
of the public. In the process of these discussions, however, I learned that our average rainfall, if harvested and
used appropriately, could replace the portion of our imported water that we use
for landscape irrigation — roughly half of the one billion dollars worth of
water the city of Los Angeles IMPORTED every year.
What seemed impossible to the agencies
was perfectly logical to me. Having participated in design and deployment of LA
City’s extraordinarily successful curbside recycling program that now serves
750,000 households, the magnitude of the task didn’t worry me. I researched and
found out that the separate water-related agencies had separate, unconnected
plans to spend a combined $20 billion in the next decade or so to upgrade or
repair their respective systems, yielding only “band-aids” with no overall
improvement in sustainability of the region.
So, I began designing a
20,000-gallon (75,800-liter) cistern that could safely fit in a small urban
yard without compromising anyone’s lifestyle or posing any threat during our
occasional earthquakes. It turned out to be a modular 2-foot-wide, linear,
recycled food-grade plastic tank that could replace the fence or wall that
separates most urban and suburban residential properties. Further, I proposed
to outfit all the tanks with wireless remote-controlled valves and pumps that
would enable flood control, water supply, and stormwater quality officials to
centrally manage the multitude of independent tanks as one highly adaptable
storage network.
The networked mini-reservoirs could
thereby perform at least triple service for potentially less money than all the
agencies’ separate projects. By adapting all the areas’ landscapes to become
functioning community forest watersheds, my system was intended to produce
multiple additional benefits such as creating tens of thousands of new
green-collar jobs, saving copious amounts of electricity (by reducing air
conditioning needs with well-placed shade trees AND reducing the pumping
required to import water over the mountains into Los Angeles), reusing all
garden and landscape biomass and prunings on site as mulch, creating a new
local plastic recycling industry product and market, and creating a
disaster-resilient backup local water supply.
This was a lovely and compelling
vision, but no one in an official capacity took it seriously. I realized I’d
need to do something to prove that the idea was feasible, both technically and
economically. That notion turned into a six-year program of design,
feasibility, and cost-benefit analysis that became known as the T.R.E.E.S.
Project (Transagency Resources for Environmental and Economic Sustainability).
It involved hundreds of engineers, landscape and building architects,
foresters, scientists, and economists who collaborated to create a book full of
designs and specifications (Second Nature, TreePeople, 2000) to retrofit or
adapt every major land use in Los Angeles to function as urban forest
watersheds. Other team members spent two years conducting a rigorous
cost-benefit analysis. And finally, we built a demonstration project, adapting
a single-family home in South Los Angeles. An overview of the story of the
T.R.E.E.S. Project can be found at www.treepeople.org/trees-project-charrette.
The demonstration site, known as the
Hall House (named for its owner, Rozella Hall), had a relatively simple set of
interconnected earthworks designed to capture, clean, store, and use rainwater
from a massive storm event, and prevent any of the rainwater or biomass from
leaving the property and thus being wasted. We built berms around the lawns,
installed a mulched swale, put in a diversion drain to pick up driveway runoff
and carry it to a sand filter under the lawn, fabricated and installed two
modular 1,800-gallon (6,822-liter) fence-cisterns which were fed by rooftop
rain gutters through a filter, then connected to the irrigation system, and
finally, planted a trellis “green wall” of climbing roses to shade and cool the
house’s sun-heated south-facing wall. We also removed 30% of the lawn and
replaced the remaining turf area with drought-tolerant grass.
Then, on a hot August day in
1998, we invited our agency partners, numerous public works officials, and the
news media to see the demonstration house. We handed them umbrellas and
unleashed a 1,500-year flood event, pumping and spraying on that one house
4,000 gallons (15,160 liters) of water in ten minutes. Officials huddled in
stunned silence as they watched the water fall and flow, pooling in the bermed
lawns and cistern. They saw that none of the water flowed to the street and
stormdrain system. They saw how, in that one instant, their annual
billion-dollar burden of separate infrastructure systems and needs were
elegantly bundled and handled. The result: no stormwater pollution, no street
flooding, no greenwaste, dramatic water and energy savings, more attractive
landscape, and potentially thousands of new jobs.
The head of LA County Public Works’
flood control division couldn’t contain his enthusiasm and proclaimed that the
simple elegance meant this demonstration could be easily replicated. A day
later, after he and his staff reviewed both our engineered designs and
cost-benefit analysis, he called me: “I’m sorry. We didn’t understand. We think
you’ve cracked it. Your idea needs to be deployed throughout the whole county,
but it’s going to cost more and take more time than you think. But despite
that, we need to begin scaling this up immediately. We’d like to try this idea
to solve one of the county’s most persistent urban flooding problems.”
That was the beginning of the Sun
Valley Watershed project, located in the City of Los Angeles’ San Fernando
Valley. After a successful two-year feasibility study, the County Public Works
Department launched a thorough “stakeholder-led” watershed management planning
and environmental impact analysis. Six years later, both the plan and
environmental report were approved; construction of the first project began
within a few weeks. The plan calls for the retrofit of 20% to 40% of the watershed’s
8,000 homes, and installation of a diverse network of earthworks. The
earthworks mix ranges from simple to complex, beginning with tree planting,
pavement removal, mulching, and berming. On the more complex end, the projects
will include installing street swales, and school watershed parks that replace
asphalt play yards with permeable greenspaces above large underground
infiltration systems and cisterns. Details of the Sun Valley Watershed Plan,
progress and planning process are available at www.SunValleyWatershed.org.
The Sun Valley Watershed planning
process informed and transformed many of the participating agencies and
organizations and inspired others who followed the process. For example, Los
Angeles County Public Works formed a new, integrated Watershed Management
Division. The City of Los Angeles Bureau of Sanitation launched and completed
its first ever Integrated Resources Plan for Water. And among several cities
outside the Los Angeles area, the City of Seattle initiated its Salmon Friendly
Seattle program, which seeks to restore viable salmon habitat throughout the
metropolitan area by revitalizing watershed and forest functionality in all the
city’s neighborhoods.
There are several keys to the
projects’ successes so far:
1) we demonstrated that these
adaptations represented acceptable and attractive lifestyle changes that would
be politically palatable;
2) we demonstrated with rigorous
engineering that they were technically feasible, safe, and capable of solving
pressing problems;
3) we demonstrated that they were
economically feasible by identifying multiple outcomes and benefits that
altogether would over time save money for the assembled funding partners; and
4) we engaged and educated all the
stakeholders from both the community (including children) and relevant
agencies.
This story is far from over. As it
continues to unfold it presents a variety of political, jurisdictional, and
regulatory issues and problems that we work to resolve. My initial vision was
that so much water and money could be saved by local governments that agencies
would help individuals and businesses cover the costs of installing and
maintaining the systems on their properties. That is now happening in some
cities, such as Santa Monica, Seattle, and Houston, that are giving grants for
cisterns and water-saving landscapes.
As we confront growing water-quality
and supply issues, plus the increased threat of flooding and weather-related calamities,
it is increasingly urgent that we find ways of adapting our homes,
neighborhoods, towns, and cities to become climate change and disaster
resilient. You have a huge role to play in protecting your household and region
by personally implementing some of the water-harvesting practices detailed in
this book. If you do this, and make yours a demonstration project, you will
help prove that it is feasible and attractive for your region. You will make it
more politically palatable, so your local politicians can pass laws, change
ordinances and codes, and make resources available to help others implement on
a wide scale. And then, collectively, we just might tip the balance and put our
nation on the road to a healthy, just, and sustainable future.
Dig in and have fun.
-Andy Lipkis
Andy Lipkis is president of
TreePeople, a Los Angeles-based social-profit organization that he founded in
1973. Andy collaborates with leaders, cities, businesses, and agencies to
identify and implement natural-systems-based solutions to human, social, and
infrastructure problems. He co-wrote, with his wife and partner Kate, “The
Simple Act of Planting A Tree: A Citizen Foresters’ Guide to Healing Your
Neighborhood, Your City and Your World”, and has been recognized and honored
as one of the founders of the Citizen Forestry movement.
