Rainwater harvesting
Revision as of 19:41, 27 December 2023 by Aesetholephews (talk | contribs)
Yield:
- 1 acre * 1 inch rainfall per year = 6.273e+6 in^3 / year = 27,160 gallons per year
- San Diego County 92-year average (minimum, std) rainfall data = 10.26 (3.41, 4.16) inches
- 75% catchment is considered good
Usage estimate:
- 50-70% of household usage is outdoors (e.g. lawns and gardens), average American uses 100 gal/day source: CT DPH
- Average American uses 82 gal/day (29,930 gal/year) source: USGS
- Average Californian uses 108 gal/day (39,420 gal/year) source: National Environmental Education Foundation
- Average American drinks 44 ounces/day (126 gal/year) source: CDC
Sustainability Estimates:
- # of Californians sustained off 1 acre (with 100% catchment), based on...
- Annual Average Rainfall: 10.26 inches * 27,160 gallons/inch of rainfall = 278,661.6 gal / 39,420 gal/person/yr = 7 persons = about 2 average households
- Minimum Rainfall: 3.41 inches * 27,160 gallons/inch of rainfall = 92,616 gal / 39,420 gal/person/yr = 2.4 persons
Storage Capacity:
- number of people * daily water consumption (gal/person/day) * longest drought period (days) = needed storage capacity (gal) Source
- 5 * 108 * 150 = 81,000 gal
Detailed resources for planning a build:
But is it legal in California?
Other resources I haven't looked at yet:
- https://www.twdb.texas.gov/publications/brochures/conservation/doc/RainwaterHarvestingManual_3rdedition.pdf
- https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015WR017871
- https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1864-2021.pdf
- https://www.watercache.com/faqs/rainwater-harvesting-benefits
- https://www.sandiegocounty.gov/content/sdc/dpw/watersheds/residential/RainBarrelInformation.html