Rain Harvesting - Bypass Overflow
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Rainwater HarvestingUnderground Water Collection System |
RAIN HARVESTING or RAIN CAPTURE is becoming increasingly popular for landscape irrigation due in part to recent improvements in drip irrigation technology. Darco manufactures both polyethylene OcTank and fiberglass tank rain water storage systems.
A one inch rain on a 2000 square foot roof generates over 1000 gallons of free water. Arid western states such as New Mexico and Arizona support and promote Rain Harvesting which returns moisture to the soil at slow absorbable rates, with very little evaporative loss, when applied through a subsurface irrigation system.
Always design your collection system for a high volume bypass to divert excess rain water that can not be filtered and stored fast enough. Also consider a tank overflow to release any excess water when the storage system is completely full. Both the bypass and overflow must be directed away from the tank and discharged where it will not cause erosion or lead to structural building damage.
We do not recommend that you drink or bathe in rainwater unless it has been treated to your local Health Department standards. Rainwater should rightfully be used in a way that returns the moisture to the earth near the location where it fell, such as through outside landscape irrigation or a septic system leach field.
Roof water generally carries leaves, dust, bugs, bird excrement, and a variety of other undesirable elements into any rain capture storage system. Filtering the water before it fills the storage system is desirable provided the filter has the capacity to process the rain as fast as it falls. This may be difficult to do in the case of a "cloud burst" event.
The second illustration depicts our Modular OcTank Rain Capture System with a simple filtration and clarifier module, upstream bypass, strainer basket, and high capacity washable fabric filter.
Any clarifier or sludge tank will require some maintenance. The strainer basket and washable filter must be cleaned regularly and accumulated silt in the bottom of the clarifier module may need to be "mucked out" every couple of years by hand or vacuum truck.

Donahoo Construction Company (Alabama): Landscape irrigation around new library using rainwater collection system / 8,000 gallons
Flintco (Arkansas): Rain capture storage and melt water for ice rink / 6,000 gallons
Chub Cay / Residential Rain Harvesting (Bahamas): Fresh water from rain water capture for individual homes / 8000 gallons
Nick Fisher Excavating (Connecticut): Rain harvesting for landscaping / 8,000 gallon cistern tank
Lafayette Recreation Center (DC - Washington): Landscape irrigation from rainwater harvesting / 8,000 gallons
Keene Project Management (Georgia): Landscape irrigation cistern tank / 16,000 gallons
Kaylo School landscape irrigation (Hawaii): Ship on low cost Flat Racks / 10,000 gallons
Kiowa County Memorial Hospital (Kansas): Landscape drip irrigation / 4 - 6,000 gallons cistern tanks
Greensburg High School (Kansas): Landscape irrigation rainwater recycling / 50,000 gallons
LaGrange Library (Kentucky): Rainwater tank for toilet flushing / 12,000 gallons
Bellarmine University (Kentucky): Landscape irrigation rainwater harvesting system / 12,000 gallons
Pillingsrud Residence (Minnesota): Rainwater backup for irrigation / 4,000 gallons
Sayreville Center (New Jersey): Commercial landscape irrigation from rainwater harvesting / 35,000 gallons
Sub-Surface Contracting (New Mexico): Rain capture systems for landscape irrigation / sizes 4,000 to 10,000 gallon cistern tanks
Bronx Community College (New York): Rain harvesting for irrigation / 40,000 gallons
Bethany Village (North Carolina): Irrigation and toilet flushing from rain storage tank / 30,000 gallons
Quail Crossing General Store (North Carolina): Rain water capture for irrigation and toilet flushing / 30,000 gallons
The Elephant Sanctuary (Tennessee): Rain water collection for elephant habitat / 40,000 gallons
Birnamwood Elementary School (Texas): Rain harvesting for irrigation / 20,000 gallons
Bank of America (Texas): Rain harvesting for irrigation / 20,000 gallons
Ferring Residence (Virginia): Residential rainwater capture system used for irrigation and fire protection / 8,000 gallons
Laramie County Community College (Wyoming): Rain capture for landscape irrigation on the campus grounds / 40,000 gallons
Darco Incorporated || 980 Darco Drive || P.O. Box 779
Bennett, CO 80102 || (800) 232-8660
info@darcoinc.com or
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