Rain catchment is our primary water acquisition strategy during Stage I. Using the formula below we can determine surface area requirements.

rain catchment formula: total square feet x .62 x annual precipitation(8 inches at Alpha Spore) = annual gallons

Estimated water requirement during Stage I(personal use per member):

drinking/cooking - @2 gallons per day (730 gallons/year)
bathing(2 modest showers) - @5 gallons per week(270 gallons/year)

So each member will need @1000 gallons of water per year for drinking, cooking and bathing.
(representing very frugal use and based on survival rather then convenience)

A 15x15 square foot catchment area will be maintained per member to achieve this, along with suitable storage(225 x .62 x 8 = 1116). This catchment area will be kept clean to preserve drinking quality. Where needed, filtration methods will be employed, such as sand/charcoal and distillation.

For gardening, rainwater will be diverted directly to swales(pdf file) and basins for soil infiltration. Small ponds will be placed throughout gardening areas or "guilds" for local storage and irrigation.
Each square foot of gardening area will need 6-8 feet of ground diversion, so swales will be spaced accordingly. Additional runoff will be diverted to swales at lower elevations and then to the ponds.

 

Other dry-land strategies will include mulching, deep watering, dense planting, and choosing drought-resistant crops.

Ultimately the water available will dictate the amount of planting we can engage in. Certain crops will have precedence over others in times of drought.