In 2005, when we began designing our Sustainable Backyard, Fairfax and San Anselmo got hit with the second 100-year flood in 25 years. We believe that climate change is causing extreme weather and raising the sea level, which only means more flooding for us.

What can we do? That is what we asked Geoff Hall and Kamala Bennet of Sentient Design, who were working with us to design a backyard that represented best practices. The said "Water Reclamation" What's that? For us it meant re-guttering our small house with about 600 square foot roof. Then channeling that water into a 1000 gallon tank. And directing the overflow of the tank into our pond and then into two vernal ponds. Our pond is lined and permanent. Our vernal ponds or swales are unlined seasonal water features. Please check the read more section below to learn more about how you can plant a vernal pond.

Since we set up this system we have found that the first rain of the season fills our tank. We actually found that in an average rainfall year we will be routing 15,000 gallons of water. We have had visits from the Town Council, County Board of Supervisors, FEMA and the Dept. of Homeland Security, MMWD, MCSTOPPP, SPAWN, Regenerative Design Institute, and numerous citizens.

Our system not only demonstrates how to help prevent flooding, it also creates unique microclimates, cleans the water before returning it to our creek systems, it helps to recharge our local ground water system, and we have 1000 gallons of water to use during the summer for topping up our pond or emergencies. In permaculture the water mantra is Slow it, Spread it, and Sink it.

Vist our backyard to learn more.

Visit the SPAWN site for more info on rainwater harvesting. 

Create your Rain Garden
A home-scale guide to harvesting rainwater

Water is the basis of all living biological systems. Civilizations around the world have been collecting and storing rainwater for over 4,000 years. Rain Gardens include both capturing and storing roof water in rain barrels and tanks for future water needs and resculpting your landscape to create swales and vernal ponds.

“By means of water, we give life to everything” Koran 2130

FACTS TO CONSIDER AND GUIDE US
• Climate change is causing extreme weather – drought, wildfires, sea level rise, flooding.
• Storm drain systems of the Ross Valley are flooding more frequently because of increased non-permeable surfaces such as driveways, roofs, roads, and sidewalks.
• Flooding, drought, landslides and toxic runoff cause financial losses, threaten public safety and deplete species dependent on our watershed.
• The Marin Municipal Water district does not have an adequate water supply to sustain the needs of the people and environment. By 2025 the supply-demand deficit will more than double.
• During the summer 50-75% of Marin treated drinking water is used for landscaping and 25-50% of that is wasted through poor management.
• Average daily water use per capita in Marin is 140 gallons. Whoa!
• 25% of the water we currently use is imported from the Russian River.
• We are currently extracting water from reservoirs and rivers faster than nature can replenish them.
• Water is a precious resource that falls from the sky for free.

CONSIDER YOUR YARD AS YOUR PERSONAL WATERSHED
Tanks and swales installed at your home safely slow, sink and spread rainwater, creating a unique growing environment for food and native plants.

RAIN GARDEN BENEFITS
• Creates solutions for flooding, topsoil loss, and toxic runoff into our creeks
• Builds self-reliance and decentralizes water resources
• Reduces impact of drought by slowly recharging our water table
• Creates a unique microclimate for food, native, and habitat plants
• Lowers water bill and treatment costs
• Manages and uses water from non-permeable surfaces
• Replenishes local water table
• Relieves strain on our water supplies
• Provides water security and disaster preparedness for fire safety and drought
• Prevents erosion of sloped areas

ROOF-WATER HARVESTING
Think of your roof as a well!
Roof-water harvesting is the storage of rain from your roof. How does it work? Simple. The rain runs off the roof, through the gutters, and into a rain barrel or tank. It is then stored for future landscape needs. Systems can be designed to collect any amount of water. All tanks and barrels should overflow into your landscape.

Things to consider when installing a roof-water catchment system:
1. Analyze location of collection tank and irrigation needs.
2. Possible retrofit and redesign of rain gutters and downspouts.
3. Rain barrel or tank should include a screen at intake and a way to drain water.
4. Position rain barrel or tank to allow access for inspection and maintenance
5. A Roof-water catchment system should direct overflow for when the tank gets full.
6. Use overflow as a resource for your swale or vernal pond.

Water collection table:
Sq. Ft. of Roof Gallons of roof runoff
1,000 24,920
2,000 49,840
3,000 74,760
based on average annual rainfall in Ross Valley for one year

SWALES AND VERNAL PONDS: Plant the Rain!
Swales are shallow (10-24”) basins strategically located to collect, spread and infiltrate water that falls on hard surfaces like roofs and driveways. Swales transform the negative impact of excess runoff on our watershed into a positive environment for food plants, natives, and habitat. Swales also prevent erosion and protect vegetation on sloped areas. They also work as a great overflow from downspout and from tank systems.

Things to consider when installing a swale or vernal pond:
1. Begin with observation. During a rain, observe the water flow and pooling patterns on your property.
2. Begin at the highest point of your yard (watershed) and work downward.
3. Begin in a small area and make it simple. If you need advice, consult a permaculturalist or landscaper
4. Swale basins should be at least 6’ away from house foundation.
6. Determine an overflow route away from your home. Manage the overflow as a resource and have final outlet at the bottom of your watershed.
7. Cover berms and swales with mulch and plant with water loving trees, natives and food.
8. Continually review your rain water systems. Landscapes evolve.