• Capture rain and phase-out using our well (see booklet at right).
• Size our garden/mini-orchard to our rainwater holding tanks.
• Build small check dams in the creek (like a beaver).
• Store rain in the ground, especially high on the land, by having as much native tree cover as the land naturally supports.
• Shape bare or disturbed land to minimize or eliminate rainwater run-off without harming native trees. Then mulch as soon as possible.
• Minimize areas of bare ground.
While the water in the creek and in our well were once rainwater, extracting water from those two sources can have a detrimental effect on life and on the hydrologic cycle in the watershed.
We never pump from the creek because pumping at times other than above normal flow has an immediate negative effect on water level, and doing this regularly means the creek dries up earlier–fish, frogs, damsel flies, water bugs and many others all die. Deer, bats, turtles, birds, raccoon, skunks and others have to travel farther to find water. The ground along the creek dries out and the depth to groundwater increases.
Since our well is near the creek, every time we use it, we are causing a draw-down of both the creek and groundwater available to creekside species like valley oak, black walnut, willow, alder, elderberry and many more. Groundwater is also mineral rich, often high in salts, and therefore a poor choice for growing plants, while rainwater is what plants evolved with. These reasons made it clear to us that we needed to switch to rainwater.
While capturing rainwater for domestic use can require the purchase of some industrial products, a setup can be installed that will last a lifetime and makes maximum use of salvaged and low cost materials. This is in contrast with well systems that overall require far more damaging materials and technologies to install, are expensive to drill, require ongoing energy inputs to run and do not guarantee a water source into the future, especially given the history of wells in this area.
We have a salvaged 3000-gallon tank that captures rain off of our roof that we use for drinking, cooking and watering our climatically appropriate food plants in our small garden. This system requires no pumps and minimal maintenance. We also have two salvaged 5400-gallon tanks for livestock and additional future garden and drinking water use. The next step in our transition towards modeling a sustainable water system here at the Center will be to experiment with earthen water tanks.
We also use rainwater harvesting earthworks in our garden, which maximize the moisture that falls on site. Additionally, building small check dams in all drainages helps to slow, spread and sink the falling water on the land, which enhances the growth and health of all plants, which boosts soil biodiversity and extends the water cycle. As noted in the list above, native trees are our best bet for keeping water in the soil, where it serves more species and extends the moist season by several weeks or even months.
Below are the calculations we used to determine numbers of plants, animals and square feet of garden beds.
A Guide for Getting Started
Rainwater Harvesting Basics
Brad Lancaster, author of Rainwater Harvesting for Drylands and Beyond, explains a few rainwater basics in the above videos and provides the following:
The Eight Principles of Successful Water Harvesting
1. Begin with long and thoughtful observation. Use all your senses to see where the water flows and how. What is working, what is not? Build on what works.
2. Start at the top (highpoint) of your watershed and work your way down. Water travels downhill, so collect water at your high points for more immediate infiltration and easy gravity-fed distribution. Start at the top where there is less volume and velocity of water.
3. Start small and simple. Work at the human scale so you can build and repair everything. Many small strategies are far more effective than one big one when you are trying to infiltrate water into the soil.
4. Slow, spread, and infiltrate the flow of water. Rather than having water run erosively off the land’s surface, encourage it to stick around, “walk” around, and infiltrate into the soil. Slow it, spread it, sink it.
5. Always plan an overflow route, and manage that overflow as a resource. Always have an overflow route for the water in times of extra heavy rains, and where possible, use the overflow as a resource.
6. Maximize living and organic groundcover. Create a living sponge so the harvested water is used to create more resources, while the soil’s ability to infiltrate and hold water steadily improves.
7. Maximize beneficial relationships and efficiency by “stacking functions.” Get your water harvesting strategies to do more than hold water. Berms can double as high-and-dry raised paths. Plantings can be placed to cool buildings in summer. Vegetation can be selected to provide food.
8. Continually reassess your system: the “feedback loop.” Observe how your work affects the site, beginning again with the first principle. Make any needed changes, using the principles to guide you.