Three outstanding local gardeners, Frank Hyman, Katherine Gill, and Bekah Resnick, contributed their ideas towards a final design for the garden; the image of their to-scale sketch is to the right (click to enlarge).
The garden site was surveyed by Bekah Resnick and Matt Ball in December of 2008; the resultant map is used on the final layout map on the right, the full report is attached, and the lay-of-the-land is described below.
The site can be approximated as a 45 ft x 165 ft rectangle with the long edge running north-northeast away from Faber Street. If the garden extends slightly into the adjacent parking lot, limiting the lot to one row of parked cars, the site will have an area of 8260 square feet (0.19 acres). If the cars park in two rows, the garden area will be 7360 square feet (0.17 acres), an 11% loss. The site rises away from Faber Street at a 6% grade.
The garden will primarily use municipal water but will be offset by some rainwater harvesting. The small storage shed planned for the garden's north corner will collect water and divert it to a storage tank. Durham sees, on average, 4.0" of rain each month (Weatherbase. An 8' x 16' storage shed would then capture 320 gallons per month. This is a minuscule amount..some augmentation of the catchment area is planned, possibly with stretched plastic sheets or even some spare solar panels. It could be feasible to quadruple this catchment area to 512 square feet. This area would intercept 1270 gallons each month. The region averages about nine rainy days a month, or around two per week. A tank designed to contain a week's worth of water would hold 43 cubic feet of water, or 320 gallons. There are currently two options for the tank:
- concrete tank, 4' tall, ~4' diameter
- using formwork, we would construct 4" walls out of concrete; the attachments tab above contains plans for octagonal formwork used by Engineers Without Borders in Uganda in 2007.
- with a 6" foundation, 24 cubic feet of concrete would be required; other reinforcement pieces would also be required
- the attached (old) water budget has a similar, slightly altered report
- plastic-lined hole
- dig a 3' deep hole in the ground roughly 4.75' x 3' and line it with thick plastic
- build a small shelter over the "pond" and screen all openings to limit insect infiltration
- see the EWB RWH page for more information and a study by the Warwick DTU on one such implementation.