Using Harvested Rainwater for Livestock Watering
Water requirements vary greatly by animal type and size. Cattle consume 7-12 gallons per day, horses 5-10 gallons, goats and sheep 2-3 gallons, and chickens about 0.5 gallons per bird. Our baseline estimate of 30 gallons per day covers a small hobby farm with a mix of poultry and small ruminants. In hot weather, consumption can double. Rainwater is generally excellent for livestock, as animals often prefer its taste over chlorinated municipal water. For poultry and small livestock, a gravity-fed system from an elevated tank provides adequate pressure. Larger operations serving cattle or horses benefit from a float-valve-controlled trough connected to the storage tank. Keep collection surfaces and tanks clean to prevent contamination, and ensure water is fresh and not stagnant.
Livestock Watering Potential by State
How much of your livestock watering demand can rainwater meet? It depends on where you live. The table below shows the annual harvest, demand coverage, and recommended tank size for livestock watering in eight representative states, using a 1,500-square-foot asphalt shingle roof .
| State | Annual Rainfall | Annual Harvest | Demand Met | Rec. Tank | Savings/Year |
|---|---|---|---|---|---|
| California | 22.2" | 13,756 gal | 100.0% | 2,500 gal | $98.55 |
| Texas | 28.9" | 22,277 gal | 100.0% | 2,500 gal | $54.75 |
| Florida | 54.5" | 39,622 gal | 100.0% | 5,000 gal | $54.75 |
| New York | 46.2" | 33,641 gal | 100.0% | 2,500 gal | $98.55 |
| Colorado | 15.9" | 11,589 gal | 100.0% | 1,000 gal | $54.75 |
| Hawaii | 63.7" | 45,229 gal | 100.0% | 5,000 gal | $164.25 |
| Arizona | 13.6" | 8,373 gal | 76.5% | 1,000 gal | $50.24 |
| Washington | 38.4" | 27,511 gal | 100.0% | 5,000 gal | $65.70 |
Setup Requirements for Livestock Watering
Livestock watering requirements vary significantly by animal type: cattle need 7-12 gallons per day per head, horses 5-10 gallons, goats and sheep 2-3 gallons, and poultry about 0.5 gallons per bird. Size your storage to bridge your longest typical dry period — livestock need water every day without exception, even during drought. A float-valve-controlled trough connected to your storage tank maintains consistent water levels automatically.
Water quality matters for animal health. Use opaque tanks to prevent algae growth, keep collection surfaces and gutters clean, and monitor water freshness — stagnant water can harbor bacteria that cause illness in livestock. For poultry, nipple drinkers connected to a small elevated tank provide the cleanest water delivery. For larger animals, a concrete or heavy-duty rubber trough with an automatic float valve ensures continuous supply. Consider adding a small amount of apple cider vinegar (1 tablespoon per gallon) to discourage algae and bacterial growth in troughs.
Other Rainwater Uses
Explore other ways to use harvested rainwater at home:
- Garden Irrigation — 50 gal/day
- Lawn Irrigation — 75 gal/day
- Toilet Flushing — 20 gal/day
- Laundry — 15 gal/day
- Car Washing — 50 gal/day
- Pool Top-Off — 10 gal/day
- Drinking and Cooking — 1 gal/day (potable treatment required)
- General Outdoor Use — 30 gal/day
- Pressure Washing — 100 gal/day
Calculate Your Livestock Watering Potential
Use our Rainwater Harvesting Calculator to see how much of your livestock watering demand can be met by rainwater in your specific location. Select livestock watering from the use checkboxes along with any other uses you are considering, and get a personalized monthly supply vs. demand analysis with tank size recommendation and cost savings estimate.