Rainwater Harvesting

Owen Edgerton

September 25, 2006

History

Developed independently across the continents India 1000BC

simple stone structures for harvesting rainwater China Loess plateau ~ 0AD

Rainwater wells and Jars.

http://www.irpaa.org.br/colheita/02.htm#1

Types of RWH Systems

Source: www.lboro.ac.uk/well/resources/fact-sheets/fact-sheets-htm/drh.htm

Rooftop Collection System

System componentsCollection Surface

Thatched; Corrugated iron.

Gutters Bamboo; Aluminum

Down pipeReservoir

Source: www.lboro.ac.uk/well/resources/fact-sheets/fact-sheets-htm/drh.htm

Gutters

Source: www.lboro.ac.uk/well/resources/fact-sheets/fact-sheets-htm/drh.htm

Reservoir Two types

Surface Sub-Surface

Materials: Metal, plastic, fiberglass, brick, compressed soil

(rubble-stone blocks), ferro-cement and concrete wood, bamboo and basket weaves as alternatives have had

variable rates of success. Usually the most expensive part of the system Tank Sizing

1 – 40m3 Residential >100m3 Commercial

RWH Safety Unpainted and uncoated surface

areas Timber treated with chemicals to

prevent rotting should never come into contact with drinking water.

Thatched Rooftops Coconut and Anahaw palms with tight

thatching are best Rodent infestation

Insect-proofing First Flush system

First flush and Filters Screen

Consumption Statistics Per Capita (1990) - 183 gal/d

http://www.epa.gov/water/you/chap1.html

Benefits of RWH 3rd World

20 liters Food security Income Generation

Southwestern United States

Sumida City, Japan Reduces extensive runoff Reduces energy use

Fiji limited freshwater resource

http://www.mccullagh.org/db9/1ds-4/sahara-desert-sand-dune.jpg

Designing a RWH System Rainfall

Quantity Pattern

Collection surface area Storage volume

http://www.eng.warwick.ac.uk/DTU/rwh/styles.html

Consumption Cost Management Advanced System

Components

Average rainfall for Biharamulo District, Tanzania

Additional Information

http://www.rainharvesting.com.au/ http://www.rainwaterglossary.com/ http://rainwaterharvesting.tamu.edu/ http://www.unep.org/dams/documents/

ell.asp?story_id=3

Rainfall - Bucks County, PA

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Rai

nfa

ll (

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Collection and ConsumptionCon=100ft^3 , rSA=420ft^2, k=.7

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Oct Nov Dec Jan Feb Mar Apr May Jun July Aug Sep

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t^3)

Collection

Consumption

Collection and Consumption

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Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec

Vo

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Collection

Consumption

Mayan - 10th Century AD

http://www.metrocouncil.org/Environment/Watershed/BMP/CH3_RPPSedCheckdam.pdf#search=%22check%20dams%22

Complete System

Collection Area Gutter Mesh Gutter Outlets Rain Heads First Flow Tank Screen Water Tank Insect Proofing Tank Top Pump

http://www.rainharvesting.com.au/create_a_complete_system.asp