rainwater harvesting: an overview

8/9/2019 Rainwater Harvesting: An Overview

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Rainwater HarvestingAn Overview

Greg Whitfield

The Rain Well

www.therainwell.com

817-676-4440

[email protected]

Greg Whitfield

The Rain Well

www.therainwell.com817-676-4440

[email protected]


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RWH Cisterns

Rainwater Harvesting is tax exempt in Texas


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Topics

Who is Rainwater Harvesting For? Benefits

Uses

Rainwater Harvesting Calculations

System Components

Storage Considerations

System Configurations

Irrigation Ideas Rain Barrels

Costs


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Rainwater Harvesting Systems

Required by law in new construction inBermuda and the US Virgin Islands.

California offers a tax credit for rainwaterharvesting systems

financial incentives are offered in cities inGermany and Japan.

Rebates are offered by Albuquerque and

Santa Fe New Mexico


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Who are RWH Systems for?

Everyone who wants to conserve naturalresources

RWH for Gardeners

Stop living off of water wells

Stop living off of municipal supplies

Your only source of water

Drink bottled water, use RW for no potableuses.


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Benefits

Savings Municipal water is becoming expensive

Digging deep wells is expensive

Vegetation

Easy for roots to absorb water without minerals andadditives

Helps recharge aquifers

Reduces flooding

Reduces erosion No build up in plumbing from hard water

Protect your investment in your landscape

If you xeriscaped your yard, continue with the water

conservation and use rain barrels


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Irrigation Garden

Indoor plants

Drinking water

Water storage for fire control Compost moisture

Fountains

Ponds

Hot tubs

Swimming pools

Stock tank water

Rainwater Uses


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Rainwater Uses

Celebrates rainwater in an artistic manner withstreams of rainwater falling over granite boulders.

HVAC intake in the cistern that can providecooler air to the house

Acoustic connection (through vents) to the waterdripping into the cistern

By using water as an organizing principle, canaddress their environmental control needs and

make the architecture special at the same time.


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Useful Facts

623.4 gallons from 1000 sq. ft. roof in 1rain

Less losses

Storage capacity

4 to 8 gallons per 1 sq. ft. roof area

Maximum amount based on need

5 inch gutters

Downspouts spaced 20 to 50 ft. apart


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Useful Facts

Live on 15 gallons of water per day Average American uses 150 gallons per day

35 inches per year

42,000 gallons per year for 2000 sq. ft. footprint

115 gallons per day

This is a significant amount of water toward the needs

of a water-conserving home

Rainfall at the rate of 1 inch per hour will yield

about 10 gallons per minute per 1,000 square feet


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Useful Facts

Rainfall at the rate of 1 inch per hour will yieldabout 10 gallons per minute per 1,000 square feet

Gain 4.3 PSI per every 10 ft. in elevation.

Pressure is not dependent on volume, only elevation

Downspouts should provide 1 square inch ofdownspout opening for every 100 square feet ofroof area.

The maximum run of gutter for one downspout is

50 feet


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System Components

Catchments Roofs

Land

Driveway Parking lots


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System Components

Conveyance Gutters

Drains

Canales


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System Components

First flush or roof washers Particulates in sky

Dust and sediment on roof

Bird and animal feces on roof


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System Components-Storage

Above ground tanks Polyethylene

Fiberglass

Metal

Ferro-cement Wooden

Stone

Soft fabric

Below ground Cement

Polyethylene

Fiberglass

Any color


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System Components-Distribution

Gravity Pumps


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System Components-Filtering

Irrigation and Drinking water Collection filters to remove large debrisand sediment

Drinking water

100 micron filter removes small sediment Charcoal filter removes taste

5 micron filter removes smaller particlesand charcoal

Reverse Osmosis removes bacteria, salts,

additives, minerals

UV sterilization removes all livingorganisms

Boiling water

Additives


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UV resistant Food grade material for drinking

No added taste

Enclosed Top Preferably with attachable lid

Aesthetic value


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History of use Added taste

Cost

Weight Large overflow port

Drain valve at bottom of tank


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How are the fittings attached Bulkhead fittings prone to leaking for small tanks

Capacity limitations

Easy to clean and maintain

Mosquito proof

Easily retrieve water

Linking options for increase capacity

Containment


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Irrigation Ideas

Overflow connected to a in ground leachdistribution system

Increases storage capacity

Overflow connected to French drain

Incorporate a drip irrigation system from drainvalve.

Incorporate in existing drip irrigation system

Check valve

Pump In line filter

Water back up

About 3000 gallons per month for typical lawns


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Rain Barrels

UV Protected Opaque Material

FDA Approved for Potable Uses

Sturdy

Round is Strongest Shape

Lid with Screened Inlet

1-1/2 Overflow

Drain at Bottom No Deep Basket Filters


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Rain Barrels

Increase capacity by mating additional tanks


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Poly Cost Example

Polyethylene Tank Cost Comparison

$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

$3.50

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500

Tank Capacity (gallons)

TankPrice(

$/gallon)

Above Ground

Below Ground


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Drought Info

Water Information Network


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Drought Info

12-Month Precipitation Deficits(February 24, 2005 to February 23,

2006)

DFW Airport 16.47 -18.26


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Drought Info

Driest DFW 12-Month Periods on Record 13.66 in. October 1, 1955 - September 30, 1956

13.92 in. March 24, 1921 - March 23, 1922

14.51 in. July 8, 1910 - July 7, 1911

rainwater harvesting: an overview

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