Urban Agroecology

I started using gray water last year in an attempt to reduce my water consumption during last year’s drought (see 10 Gallons of Grey Water). Now we’re into 2009 and it’s clear we’re going to have another tough year for water. Both my winter crops and my drought-tolerant plants need water, because we haven’t had our usual winter rains.

The ornamentals, in particular, are Mediterranean-climate plants. They are used to dry summers but get through them because they have adapted to heavy winter rains and dry summers. Because we’ve had much less rain than usual this winter, I’ve started irrigating them to make sure they get what they need to make it through the summer. That means I’ve started using gray water in January, not June. I thought it would be interesting to track this during the year, to see how much water I can actually use instead of letting it run down the drain. While my methods aren’t the most efficient, they do allow me to save a significant amount of water for irrigation. So, follow along with me during the year to see how much water I end up saving.

I have three primary sources of water that I save:

• Laundry rinse water: Technically, this is the only true gray water, as it has already been used for another purpose and collected on it’s way to the drain. To keep it simple, I use this on my ornamentals instead of my food crops, so I don’t have to take any special precautions with the food crops. If I’m on top of it during the wash cycle, I can get two five-gallon buckets of rinse water, one from the wash cycle, one from the rinse cycle. Normally, however, I just let it keep flooding over into the laundry tub, so I just get rinse water, which is pretty clear of detergent.
• Shower: I keep a bucket handy and run water into it while I’m waiting for the hot water. I get slightly less than one gallon from each shower. Since this is clean water, I use it on my food crops.
• Hot water tank overflow: The relief valve on my hot water tank always let’s a little water out after I’ve showered. I simply have a bucket next to the heater that catches this overflow. I get about 2.5 gallons a month this way. But, it’s clean water so it’s easy to use on my food crops.
• Other: Occassionally I save small amounts of water from other sources, e.g., cold water from the kitchen sink while waiting for hot water. In addition, whatever rainwater collects in my garden buckets goes here.