There are harvesting advantages such as
- Makes use of natural resource and reduces flooding, storm water runoff, erosion, and contamination of surface water with pesticides, sediment, metals, and fertilizers.
- Depending where you are harvesting it could reduce the need for importing water.
- Excellent source of water for landscapes.
- May reduce water bill
- Promotes both water and energy conservation
- No filtrations system is required for landscape
- Limited and uncertain local rainfall
- Can be costly to install depending on system
- The payback period varies depending on the size of the system
- Can take considerable amount of time to “pay for itself”
- Certain roof types may seep chemicals, pesticides, and other pollutants in the water that can harm plants
- Rainwater collected during the first rain season is generally no needed by plants until the dry season.
Another disadvantage to harvesting rain is it may very well be illegal depending on which state you live in. Colorado has passed recently to legalizing the right to harvest rain but it does come with strict regulations. The two Colorado laws allow perhaps a quarter-million residents with private wells to begin rainwater harvesting.
State officials acknowledge that they rarely enforce the old law. With the new laws, the state created a system of fines for rain catchers without permits.
Senate Bill 09-080strict limits that apply
- Harvesting takes place on residential property
- The owner of the property has a legal entitlement to a well
- No water is provided in the area by a water district or a municipality
- The roof is the only location collecting rainwater
- The collected rainwater is put to uses explicitly permitted in the well permit
Given these restrictions most of us may not harvest rain.