rainwater harvesting owen edgerton september 25, 2006
TRANSCRIPT
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
0
1
2
3
4
5
6
Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec
Rai
nfa
ll (
in)
Collection and ConsumptionCon=100ft^3 , rSA=420ft^2, k=.7
0
200
400
600
800
1000
1200
1400
1600
1800
Oct Nov Dec Jan Feb Mar Apr May Jun July Aug Sep
Vo
lum
e (f
t^3)
Collection
Consumption
Collection and Consumption
0
20
40
60
80
100
120
140
160
180
200
Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec
Vo
lum
e (
ft^
3)
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