My building just got new gutters and according to the new set of rules laid out by the City of Portland, OR, I now have a downspout that spouts right into my garden bed.
SOLUTION: Raid Garden!
Here's what you'll need
Shovel, medium sized (a little bigger than a fist) river rocks, pumice, sand and some smooth decorative rocks if you feel so inclined.
First, it's good to know about how much rainfall you get, how much roof-surface area feeds to your downspout, etc... but I just figured I'll build it and see how it goes.
I dug a 2ft deep, 2ft wide roundish hole and dumped the medium sized river rocks into the bottom and reserved enough of them to line the rim for the aesthetic effect. Next (somewhat counter intuitively) I poured in enough sand to cover the rocks, then added the crushed pumice stone on top. Lastly I collected some smooth, dark stones from the river (ssshhh! don't tell anyone - yea right this is a public blog...) and placed them neatly on top.
I also selected two different types of water-loving native grasses and planted them around the ring of rocks I made from my left-over medium sized river rocks.
Looking down at my work, I was please with the way it looked, but had no idea whether what I had made would be sufficient in size to absorb and contain water from a typical rainfall in Portland. Luckily, it would soon be put to the test.
Success, we had a pretty hard down-pour for about 2.5 hours two days later and when it calmed down a bit, I went out to inspect my creation. VOILA! No puddles in my garden bed, the reservoir was about 75% and draining at a reasonable rate (even after all that rain) and as an added bonus there were two little birds perched on the rocks I used to rim the hole drinking from the accumulated rain water. Of course they scattered as soon as I went outside, but I was proud to have created a mini ecosystem for the thirsty wildlife around my apartment complex.
Feel free to comment or ask questions about projects of your own!