Rain Water Harvesting & Condensate RecoveryNew Tools for
Sustainable Site
Development
by
Tom Barrett
Green Water Infrastructure
C o p y r i g h t © 2 0 1 0 b y To m B a r r e t t
Chicago
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
How Much Rain Falls in Chicago?
January - 1.86"February - 1.58"March - 2.59"April - 3.28"May - 3.75"June- 4.08"July - 3.39"August - 3.38"September - 2.91" October - 2.65"November - 2.09"December - 1.88"Total 33.44"
Image of Rain Falling
Graph of Chicago Rain Fall
Thirty Year Average Monthly Rain Fall
Chicago(1971 - 2000)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
January February March April May June July August September October November December
Month
Inch
es
How Much Water Falls in Chicago?
January - 2,727 gallonsFebruary - 2,540March - 4,130April - 5,735May - 5,268June- 5,657July - 5,470August - 7,200September - 5,096 October - 4,223November - 4,691December - 3,787Total 56,525
Image of Rain Falling
2,500 sq. ft. Roof
How Much Water Falls in Chicago?
January - 11,880 gallonsFebruary - 11,065March - 17,990April - 24,982May - 22,945June - 24,642July - 23,828August - 31,363September - 22,199 October - 18,397November - 20,434December - 16,496Total 246,221
Image of Rain Falling
¼ Acre Residential Property
How Much Water Falls in Chicago?
January - 142,560 gallonsFebruary - 132,784March - 215,876April - 299,783May - 275,344June - 295,710July - 285,934August - 376,358September - 266,383 October - 220,764November - 245,203December - 197,954Total 2,954,654
Image of Rain Falling
3 Acre Commercial Property
How Much Water Falls in Chicago?
January - 475,195 gallonsFebruary - 442,610March - 719,581April - 999,267May - 917,805June - 985,690July - 953,105August - 1,254,515September - 887,936 October - 735,873November - 817,335December - 659,842Total 9,848,756
City Block (660’ x 660’ – 10 acres)
How Much Water is in Rain Event?¼” Rain ½” Rain 1” Rain
2,500 ft. sq. Roof
390 gallons 779 gallons 1,558 gallons
¼ Acre Residential Property
1,697 3,994 67,789
3 Acre Commercial Property
20,366 40,731 135,770
Chicago City Block
67,885 135,770 271,540
What can we do with this water?
• Flush Toilets• Wash Vehicles• Clean Sidewalks• Laundry• Water the
Landscape
How Much Do We Use?
DailyMonthly AnnuallyToilet - 19 gallons 570 6,840Bathing - 15 450 5,400Laundry - 8 240 2,880Kitchen - 7 210 2,520Housekeeping - 1 30 360 Total 50 1,500 18,000
The average household uses between 50 and 100 gallons of water per person per day.
How Much Water Does a Landscape Need in Chicago?
January - 0.00"February - 0.00"March - 0.68"April - 2.01"May - 3.95"June- 5.89"July - 6.99"August - 6.07"September - 3.87" October - 2.08"November - 0.63"December - 0.00"Total 32.17"
Graph of Chicago Evapotranspiration
Evapotranspiration(Chicago)
-1
0
1
2
3
4
5
6
7
8
Month
inch
es
Evaportation
Graph of Chicago Rain Fall & Evapotranspiration
Precipatation(Chicago)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Month
inch
es
Rain Fall
Graph of Chicago Rain Fall & Evapotranspiration
ET vs. Precipatation(Chicgo)
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-4
-2
0
2
4
6
8
Month
inch
es Rain Fall
Evaportation
Difference
What is the Problem?
ET Rain DifferenceJanuary - 0.00" 1.75" 1.75" February - 0.00" 1.63" 1.63" March - 0.68" 2.65" 1.97" April - 2.01" 3.68" 1.67" May - 3.95" 3.38" -0.57" June- 5.89" 3.63" -2.26"July - 6.99" 3.51" -3.48"August - 6.07" 4.62" -1.45"September - 3.87" 3.27" -0.60"October - 2.08" 2.71" 0.63"November - 0.63" 3.01" 2.38"December - 0.00" 2.43" 2.43"Total 32.17“ 36.27" 4.10"
Landscape Ecology
Size the landscape to the 80% of the average rain water production.
– Roof Runoff
– Hardscape Runoff
Balancing rain water to landscape creates a functional landscape that utilizes the site’s water production.
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
– Collection runoff near the source
– Slow it down
– Soak it in
– Filter it
– Apply it to the landscape
– Create habitats
Peak Flow(1 Acre Site)
Grass Field Roof
1 Year Storm 1.4 cfs 4.3 cfs
2 Year Storm 2.1 cfs 5.4 cfs
10 Year Storm 4.3 cfs 8.0 cfs25 Year Storm 5.7 cfs 9.5 cfs
100 Year Storm 8.0 cfs 12.0 cfs
cfs – cubic feet per second
Peak Flow(1 Acre Site)
Grass Field Roof
1 Year Storm 10.5 gps 32.2 gps
2 Year Storm 15.7 gps 40.4 gps
10 Year Storm 32.2 gps 59.8 gps25 Year Storm 42.6 gps 71.1 gps
100 Year Storm 59.8 gps 89.8 gps
gps – gallons per second
Peak Flow(1 Acre Site)
Grass Field Roof
1 Year Storm 630 gpm 1,932 gpm
2 Year Storm 942 gpm 2,424 gpm
10 Year Storm 1,932 gpm 3,588 gpm25 Year Storm 2,556 gpm 4,266 gpm
100 Year Storm 3,588 gpm 5,388 gpm
gpm – gallons per minute
Peak Flow(2,500 sq. ft. Roof)
Grass Field Roof
1 Year Storm 0.08 cfs 0.25 cfs
2 Year Storm 0.12 cfs 0.31 cfs
10 Year Storm 0.25 cfs 0.46 cfs25 Year Storm 0.33 cfs 0.55 cfs
100 Year Storm 0.46 cfs 0.69 cfs
cfs – cubic feet per second
Peak Flow(2,500 sq. ft. Roof)
Grass Field Roof
1 Year Storm 0.60 gps 1.85 gps
2 Year Storm 0.90 gps 2.32 gps
10 Year Storm 1.85 gps 3.43 gps25 Year Storm 2.44 gps 4.08 gps
100 Year Storm 3.43 gps 5.15 gps
gps – gallons per second
Peak Flow(2,500 ft. sq. Roof)
Grass Field Roof
1 Year Storm 36 gpm 111 gpm
2 Year Storm 54 gpm 139 gpm
10 Year Storm 111 gpm 206 gpm25 Year Storm 147 gpm 245 gpm
100 Year Storm 206 gpm 309 gpm
gpm – gallons per minute
Stormwater Effects of Urbanization
Change in Peak Runoff FlowBefore and after Development
0%
50%
100%
150%
200%
250%
1 Year Storm 2 Year Storm 10 YearStorm
25 YearStorm
100 YearStorm
Rain Barrels
Video Jug
How to Build a Rainwater Collection System Video
www.Videojub.com
Collection and Dispersal
Collection Systems
– Rain Barrels
– Downspout Collection
– Cisterns
Dispersal Systems
– Rain Gardens
– Bioswales
– Irrigation
Rain Barrels
Rain Barrels
• Collect a small amount of water– 50 to 300 gallons
• Can be unattractive
• The water must be used
Downspout Collectors
Downspout Collectors
Captures 90% of the rainwater
Cisterns
Above Ground
Cisterns
Below Ground
Video
Installing a 30,000 gallon Cistern In Four Minutes
Putting It Together
Control Systems
Sensors plus Logic Circuits
Cistern Sensors
• High Water – Disperse the water– Alarm
• Irrigation Water– Reserve for landscape
• Household Water– Minimum if household water use
• Low Water l– Pump protection
Irrigation System
• Soil moisture
Drip Irrigation Systems
90% Efficiency Rating
Expanding Stormwater Detention Systems into Stormwater
RetentionSmall increase in size creates a large increase in volume.
Small increase in cost delivers a large volume of water.
Mitigates the ¼” to ½” rainfall events.
Condensation
Condensation
Condensation
Untapped Reservoir
Untapped Reservoir
HVAC Condensation
• ½ gallon per hour per ton of air conditioning.
• 1,000 ton air conditioner produces 8 gallons of water per minute.
• Condensation production occurs when the landscape needs the water.
HVAC Condensation
• ½ gallon per hour per ton of air conditioning.
• One ton of air conditioning for every 700 sq. ft. of floor space.
• One ton of air conditioning for every 5,600 cu. ft. of building volume.
Residential Condensation
• 8 to 15 gallons of water per day.
• 60 to 100 gallons per week.
• 250 to 450 gallons per month.
Commercial Condensation
• 15 gallons of water per minute.
• 360 gallons of water per day.
• 2,520 gallons of water per week.
• 10,000 gallons of water a month.
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Green • Water • Infrastructure
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
Untapped Reservoir
Questions?
• Green Water Infrastructure• Strategic Planning
• Marketing• Coaching• Training
Tom BarrettGreen Water Infrastructure, Inc.P.O. Box 124Westfield, Indiana 46074(317) 674-3494
