Water Table/ Drought Discussion
Wherever you are trying to grow food, you need water.
One of the chief reasons I relocated to my present location was the healthy aquifer. Yes, I am in an area with much lower population density; but that's also true of a desert. You cannot raise as much food per acre in, say, Death Valley.
Knowing your present location's conditions and the history of rainfall and temperatures is only the baseline. Future fluctuations in weather/climate may mean that you may have a drier or wetter year than your region typically has, and fluctuations in temperature can affect transpiration (the rate at which plants lose water through their leaves.) Knowing how to deal with these fluctuations can mean the success or failure of your garden or small farm. Here are some ideas on how to cope.
You have it tough in that your city water is pretty expensive, and your land is often contaminated. But it's getting easier to get land to garden on, thanks to the growing popularity of urban farming. Indoor airponic and hydroponic large-scale farms are also an option. For small gardeners, consider the following strategies: mulch your crops to stop evaporative water loss from soil–even in small container gardens on your balcony–and make extensive use of greywater. You also have a lot of rooftops to collect rain water from.
One of the challenges to urban gardening is the dust dome effect that causes your area to be hotter in the summer (northern hemisphere). Edible greenery will not only clear and cool the air somewhat, but less trucking in food from outlying farms will decrease the amount of hydrocarbons in the city air.
Everything is so…spread…out in the suburbs. Certain activists think that suburbia is a horrible place, doomed to failure as fossil fuels become more and more expensive. But if you telecommute, and have a kitchen garden in your yard, it's not your parents' suburbia. If you wish you could move to the country but are stuck in the 'burbs due to job-related issues you can bloom where you're planted by adding edible landscaping, a kitchen garden, and what ever fruit and nut trees you have room for. Still, how do you keep it all green and growing? Water.
At a minimum, your suburban roof can be a rain catchment system (really good link!) irrigating your mulched plants – with rain barrels, or even a rainwater tank if your local rules allow it. Rain gardens allow for any slope in your land to push water toward certain crops, especially trees and bushes. Other options are a well–readers here have had great things to say about Simplepump.com–or a wicking bed, or drip irrigation. And make sure your soil has enough compost to retain water! It's also important to make sure that you have sufficient drainage for any wetter-than-usual years. because plant roots need air: plants can drown.
I am not suggesting that you buy or keep an oversized consumptive McMansion, but there are worse fates than sharing your excess vegetables and fruits with your suburban neighbors.
Rural Gardens and Small Farms
People in this situation can scale up all of the above suggestions, but if they have the room they can also excavate a pond, and add soil berms to grow things with the rain that falls on the property or water streams that run through it. I especially suggest looking at Geoff Lawton's description of how he turned a .5-acre property into an abundant food-producing place by altering the flow of water. Free video here, and although he does request your email address, that's just to let you know when a new video comes out. Rural spaces probably mean you have room to add full-sized fruit and nut trees appropriate to your climate. Lucky you.
So, what are some strategies to deal with drought and climate change that have worked for you?
I especially suggest looking at Geoff Lawton's description of how he turned a .5-acre property into an abundant food-producing place by altering the flow of water.
I hate to come off as a nitpick, Wendy, but Geoff's video was on a 5-acre property. A very, very big difference from a 0.5 acre property as I'm sure you'd attest.
I think that your citing aquaponic/aquaculture systems is dead-on, not only as a means to keep water in the landscape (aquaculture), but also in terms of yield. If you have the topography and space to put in a good sized pond, you can get an order of magnitude more protein yield from fish than you would get from livestock on an equivalent area of land. While aquaponics rely on a good bit of non-renewable resources, I think that for those on smaller lots or even urban areas, the amount of yield you can get from such systems is more than worth the energy/material costs of the infrastructure.
I'd also add in the idea of terraforming to slow, spread, and sink water throughout the landscape. I have one of my roof gutter drains diverted over an arbor and to a small swale at the head of my forest garden space. All that runoff fills the swale and creates a lens of water in the subsoil, which the trees and shrubs can then access during dryer periods of the year.
There is a reason I listed that under rural alternatives, since rural gardeners/small farmers often have more land.
We only have 1/3 of an acre but border on a high tension wire utility right of way where we can plant additional things.
Great write-up and excellent links. 🙂
Included were couple of water conserving backyard gardening ideas for Californians with very limited water.
Self-watering ("wicking") planters deliver water into the soil about a foot below the surface. This greatly limits water loss from both soaking into the ground and evaporation from the surface of the soil.
A couple of very bright teenagers explain how to make it:
2. Or a much bigger 300 gallon IBC container cut in half. These containers are available used for about $90 on craigslist. Be careful to only purchase containers that contained FOOD, not industrial chemicals.