Just refilled the reservoir and metered the fill. Went through 2,000 gallons in 17 days. And when I do the math, that's only about 1.75" of loss/week, which is about what I'd expect during the summer with the pond in full sun, lots of water movement, and 24/7 wind for a week straight.
Pretty wild, though. When I designed the reservoir, I was counting on enough small rain events through summer to refill it long enough to make it to the next one. But that did not happen last year. And, so far, no signs of it happening this year either.
Meanwhile, it was one of the wettest springs in history. Such is the problem with these designs. More water than you could ever handle when you don't need it. Nothing when you do.
I also conveniently forgot that the last 500 or so gallons in the reservoir aren't really usable without damaging the pumps. So, my 2,500 gallon reservoir is more like 2,000 realistic gallons.
I calculated that I have space to store about 7,000 gallons of water under my deck—an awkward space I keep trying and failing to successfully store anything else. Maybe one of those rain pillows would work? Or some other rigid solution? Would get me through 2-3 months of dry summer weather. Perhaps long enough to actually get some rain before going dry.
I think a thick, green lawn would actually be better for water conservation than a pond. At least in this back yard. But you can't sit on the deck and listen to a lawn. Or swim in it. Or catch tadpoles and watch baby ducks swim. Or plant things you don't have to water.
Hell, might as well convert the rest of the lawn into more pond.
