and not a drop to irrigate. My husband and I fell in love with a piece of Clackamas county a couple of weeks ago…great price, good location, perfect aspect, on a paved but quiet road, excellent soils. There is water on the property, a creek runs along the bottom, and there is at least one spring, and a wellhouse with a newer looking pump, two good outbuildings and a house that needed a lot of work. The well is not to be found on any county or state record, and the land has no water rights. It is also in an area of poorly producing wells (the average is about 11 gals/minute) so there is no chance of getting a right from the county. So from a vegetable farming perspective, this piece may as well be in the Sonoran Desert. We liked it so much I began a flurry of research, primarily in rain water harvesting (in Oregon you can legally harvest water off of any impermeable surface, such as your roof, for any purpose without a water right). Here are some of the numbers I came up with.
Let’s say I want water for one acre of water needy vegetables. Our droughty season here is about 3 months. I will need to water my acre a minimum of an inch a week (now if I am using drip irrigation of course my needs will be less, and if I use dryland farming techniques and possibly even some hugelkultur beds it would be less still, but what that fraction is exactly I won’t know until doing).
Assuming I was going to overhead irrigate my acre an inch a week for the 12 weeks I would need to get through Oregon’s dry season I need one acre foot of water (the amount of water required to cover an acre 1 foot deep). An acre foot of water is 325,852 gallons. The number of gallons in a cubic foot of water is 7.4. In Oregon, I can legally harvest all the rain that doesn’t hit the ground (i.e. what hits the roof). Average rainfall in Clackamas county is about 40 inches. Lets say I have a barn with a 3000 square foot roof…Area times inches of rain divided by 12 times 7.4 gallons gives me….74,000 gallons. Or, about 23 % of my needs. Water is bulky and expensive to store….the cheapest tank I have seen was a community built (ie free labor) ferrocement tank that cost about $.75 per gallon. Most tanks run more like $1 to $1.25 per gallon, depending on materials (you might be able to find cheaper tanks used). There is also site prep, installation, and plumbing costs. You can do the math there…..rainwater may be free but storing it is really really expensive.
The cheapest way to store water is in a pond (I don’t have a good figure for this per gallon, I think it varies depending on soil type, site, who does the earthmoving, and size of pond). Unfortunately in Oregon, if you are planning to store rainwater for irrigation in a pond, it has to have a berm (so no water that hits the earth will go into it) and be lined with plastic (so it can’t have any hydro-connection to the ground water system). I was very sad to learn this, because of course, who wants a big sterile plastic lined pond? Not me. Plus the plastic liner puts the cost of the pond more in line with tanks. I was also very sad to learn that the beautiful and logical keyline and pond system of water harvesting used by permaculturalists in arid regions (which injects water back into the system while providing ponds for irrigation, aquaculture, livestock and human pleasure) is illegal in Oregon if you plan to use the ponds for irrigation. The genius of this idea is that you are using swales and plantings to slow rain water flowing across your landscape and allow it to absorb into the soil, so the soil is the primary storage vessel. The water isn’t stopped really, just slowed down, so the system actually (through limiting speedy runoff and evaporation) adds to your property’s water bank. Using swales in this way can even create springs in theory. The definitive text (which I have just ordered but I haven’t read yet) is P.A. Yeoman’s book Water For Every Farm.
There was a fabulous presenter at this year’s OSU Small Farms Conference (this last weekend in Corvallis) who basically admitted that he was using his keyline and pond system illegally. He lives in a county where he can get away with it. He also has water rights to a stream, and a great well, so he has backup options should the powers that be ever change their minds. I am not sure I would be comfortable embracing this system as my only source of water for production and base my business on it. Which puts us back at square one in terms of looking at properties. We have to walk away from that pretty piece of Clackamas county.
Everyone talks about financing land as the primary obstacle to small farmers getting started in agriculture. I would add to that that we need to rethink our water use and water laws in this state if we truly want the younger generation to get started in small scale sustainable agriculture. I have looked at a lot of smaller properties (10 to 50 acres, a size that young farmers might be able to afford) that had beautiful soils and were well suited to sustainable crop production, but they have no water rights. When larger farms parcel out acreage to generate revenue, they usually keep the water right (and who could blame them?) for themselves, divvying up and limiting a lot of good agricultural lands to a system that can only produce McMansions and maybe some livestock. And the groundwater and surface water systems are already overtaxed….wells in Clackamas county are drying up, elaborate deals are being made with water rights holders across the state to ensure that native fish have enough water to support healthy populations, so even I can’t advocate for additional water rights to surface and ground water systems.
Western Oregon gets 40 inches of rain a year, plenty to support agriculture through the dry seasons if we are wise in our use of it and creative in how we capture and save it. John Wesley Powell when he explored the west recommended a watershed based system of community building. Instead we got a hierarchical system based on precedent overlaid on a grid that pays no respects to soil types and natural boundaries. So wish me luck in my land hunt, for I am going to need it.