Water Catchment
Catchment Potential and Example
It is possible to catch about 1/3 of the water needed for household use in the area of the Ranch. For example:
- A 2,000 sqft home that uses the roof area for catchment can collect approximately 18,000 gallons in an average year (see calculations below).
- 18,000 gallons is 15% of the average American home using 300 gallons per day, or nearly 43% of the needs for a conserving home that uses 120 gallons per day.
This is a meaningful amount of renewable water. You can add additional square footage from overhang areas, a barn, utility building, or the like to add to the total. If you double the area, you can catch all the water you need in a good year from a renewable source.
Calculations
The Assumptions
The El Vado station registers 14.3 inches of rain per year in the immediate area of Yellow Hills Ranch, although in the past two years there has been significantly more than that. The following calculations use the yearly average rainfall to calculate the amount of water that falls within the following described areas.
The Formula
(7.48 gallons/cubic feet x sqft of catchment area)/12 * 14.3 inches of rain = gallons/year
Rainfall On One Acre
We assume 14.3 inches per year, the average reported at the El Vado weather station.
One Acre = 43,560 sqft = 208.71' X 208.71' (if square)
That means 388,305 gallons, or 1.1917 acre feet, of water fall on one acre in a year's time.
Total Ranch Rainfall
1.1917 acre feet fall of water falls on each single acre of land. That means a total of 5,652 acre feet, or 1.841 billion gallons of water falls on 4,743 acres of the property.
Residential Use
The total water use projected for all residential purposes at Yellow Hills Ranch is in the range of approximately 90 acre feet. That represents just 1.6% of the total amount falling on the land.
The water use that is carefully regulated when a Master Plan is considered is the amount used in residential applications, in this case just 1.6% of the water involved. Yet the entire surface water management opportunity is nearly ignored. The expression "can't see the forest for the trees" comes to mind. A lot more information about this subject can be found on our Surface Water Management page.
Water Collection Based on Various Roof Area Sizes
- 2,000 sqft collects 17,829 gallons, or 0.0547 acre feet
- 3,000 sqft collects 26,743 gallons, or 0.0821 acre feet
- 4,000 sqft collects 35,657 gallons, or 0.1094 acre feet
- 5,000 sqft collects 44,571 gallons, or 0.1368 acre feet
Catchment can be simple