rainwater harversting

what is rainwater harvesting?

the capture, diversion, and and storage of rainwater for use in landscape, rangeland, etc.

where can rainwater be used?

• in home: flush toilets, water plants, drinking water!

• landscapes

• livestock/pet watering

• buildings (irrigation/toilets)

• groundwater recharge

• commercial and industrial

• firefighting

• wildlife

what is passive collection?

spreader dams, ridges in soil, stock tanks, basins, etc.

*what is the harvested water formula?

harvested water (gal) = catchment area (ft²) x rainfall depth (in.) x 0.623

for each 1 in. in rainfall, each ft² collects 0.6 gallons of water

what equipment is used in RWH?

1. filters/screens

2. storage tanks (plastic, metal, large, small)

3. first flush diverters (avoids large debris by diverting first rush of rainwater from roof)

4. piping/valves

how can RWH be used for livestock?

A Cedar Post Frame, Tin Roof and Gutter, Livestock Water Trough and a Livestock Watering Pan. Buried to Ground Level - Provides Water.

two tin roofs slanted inwards for collection!

how can RWH be used for small animals?

A Rain Barrel And Water Hose Can Be Connected To A
Pet Watering Pan Or A Drip Irrigation Emitter To Provide
Water For Birds, Pets Or Wildlife.

*water treatment (disinfection options):

1. filtration:

• can remove some germs and chemicals

2. chemical disinfecting (chlorine) or boiling: 

• Treating water with chlorine or iodine kills some germs but does not remove
  chemicals or toxins.

• Boiling the water will kill germs but will not remove chemicals.

3. Irradiation with UV light

4. Ozonation

details about irradiation with UV light:

Irradiation with UV light produces minimal byproducts and provides
disinfection of bacteria and most viruses:

• Requires high level of filtration

• Does not affect algae

• Cryptosporidium and Giardia may not be completely inactivated

• UV systems are easy to install and fairly economical to operate and maintain

• No residual protection

advantages of ozonation:

• effective over a wide pH range and rapidly reacts with
  bacteria, viruses, and protozoans

• has stronger germicidal properties than chlorination

• It has very strong oxidizing power with a short reaction time.

• The treatment process does not add chemicals to the water.

• Ozone can eliminate a wide variety of inorganic, organic, and
  microbiological problems as well as taste and odor problems

disadvantages of ozonation:

• There are higher equipment and operational costs and it may be
  more difficult to find a professional proficient in ozone treatment
  and system maintenance.

• Ozonation provides no germicidal or disinfection residual to inhibit
  or prevent regrowth of bacteria.

• Ozonation produces by-products, some by-products may be
  carcinogenic. These include brominated by-products, aldehydes,
  ketones, and carboxylic acids. This is one reason that the post-
  filtration system may include an activated-carbon filter.

• The system may require pretreatment for hardness reduction or the
  addition of polyphosphate to prevent the formation of carbonate
  scale.

• Ozone is less soluble in water, compared to chlorine, and,
  therefore, special mixing techniques are needed.

• There are potential fire hazards and toxicity issues associated with
  ozone generation.

details about surface catchment area:

• Area calculation (square feet)

• Bird’s Eye view concept

• Metal roofs vs asphalt shingles