Rain Garden - Open Thread

We're installing a rain garden system (including a pair of above-ground cisterns) to help manage the runoff from our land. I'll post a more complete description as I develop it.
Here's a slideshow of the project as it is constructed:

To see individual photos (and Jake, feel free to copy them to your portfolio!) see here:

Rain Garden

Purpose

Do something about the water that falls on our land. Most of it is wasted and, worse, flows almost directly into the stormwater control system which is frequently overloaded, resulting in untreated water going into Puget Sound. By managing the water properly, we can earn the private benefit of inexpensive water for our plant while accomplishing the public purpose of reducing excess runoff. Everyone wins!

Planning

Figuring out how to do this involves creating a plan for the physical labor to be done, plus financing (a good idea that you can't afford is no good!) We had been working on some ad hoc efforts in our front yard, but for the major effort of dealing with our thousand-square-foot roof and the equally large backyard, we needed some help. Luckily, our area has a runoff problem and the water utility has decided one approach is to help homeowners do something about it. Through the Seattle Rainwise program, if we install approved combination of cisterns and raingardening, we'll get a large chunk of the cost covered; it's as if we're building a tiny water treatment plant for the city! Think about how sensible this is; instead of building one 500,000 holding tank and a HUGE bioremediation garden or other treatment plant, a thousand homes could install 500 gallons of cisterns a raingarden and accomplish much the same result! Only it'd be better because homeowners and neighborhoods also reap the benefit of the garden! The major difficulty in the financing comes from the utility requiring that we front the money to build the system; only after it's constructed and approved do they cut a check. This is reasonable of course, but it meant we needed to shop around credit unions to find the best deal on up-front money.

Principles

We want to be as environmentally and economically smart as possible. In particular, we wanted to minimize the amount of waste hauled away as the back yard was reformatted. I'd had good luck re-using the sod from other projects, and was eager to apply the re-use principle where practical. For this project, we were going to have to do something about an aging concrete patio laced with cracks. We ultimately chosen to bust up most of it, converting its impermiable surface into additional garden space, and use the "urbanite" (broken concrete) for walls in a raised garden. We (and by "we" I mostly mean the guys who did the actual work) also re-used most of the left-over tree limbs from the snag we took down early this year; they were integrated into the walls in a form of hugelkultur, holding the dirt in place until plants establish roots sufficient to carry on the job.

Installation

For a contractor, we checked Rainwise's list of approved contractors and picked Stone Soup Gardens. Besides the threshold qualification of being on the approved list, we wanted a contractor who was relatively close geographically speaking (it just didn't make sense to have environmental work done by someone with a long commute!) and whose web presence seemed in harmony with out values and intents. Contracting is an intimate relationship that can be very expensive if it goes wrong! ...I'll write more later ....