WaterSmart Horticulture
Frank Henning
UGA Watershed Extension Agent, fhenning@uga.edu
Why is water an issue in Georgia?
Projected Water Demands in Barrow, Clarke,
Jackson and Oconee Counties
Millions of Gallons Per
Day
Population & Water Use in
Georgia, 1950 - 2000
30
25
20
15
YR 2000
YR 2020
YR 2050
10
5
0
Barrow
Clarke
Jackson
Oconee
Years
• 9.5 million people depend on a clean water supply
• Population is increasing by more than 2.2 % a year
• Water Use increased 20% between 1990 – 2000
Source
Amount (Gallons per Day)
Toilet
18.5
Clothes Washer
15.0
Shower, Bath
12.8
Sinks, Faucets
10.9
Leaks
9.5
Dishwasher
1.0
Other Sources
1.6
Total Indoor Water Use
69.3
Total Outdoor Water Use
30 – 40
How much water do plants need?
Shrubs:
Apply 1 GALLON of water per foot of plant height
up to once a week.
Lawns & Groundcovers:
Apply up to 1”of water per application up to once a week
Trees:
Apply 1 INCH of water under entire canopy
up to once a week.
(for larger trees don’t water area within 4 feet of trunk)
How much water can we harvest?
Rainfall in Athens, GA 2007 (drought year)
Month
April
May
June
July
August
September
October
November
Rainfall
(inches)
1.8”
0.55”
2.23”
3.04”
1.31”
2.15”
1.61”
2.12”
624 gal/in
*0.75
468
468
468
468
468
468
468
468
Harvest
volume
(gal./1,000ft2)
842
257
1044
1423
613
1006
753
992
• Per capita water consumption in the U.S. exceeds 100 gallons/day
• Water use increases 30% - 50% during the summer months
• Landscape use can 59 – 67% total home water demand (AWWA)
Condensate Harvesting Potential
AC production
Are landscapes important?
• Reduce heat island effects
• Filters air and water
• Reduce runoff, permit infiltration
• Erosion Control
• 1 tree can remove 26 lbs of CO2 from the atmosphere, or
11,000 miles of car emissions
Multiply by 7 to
convert to gallons
per week
Multiply by 4 to
convert to gallons
per month
Example: 7 gpd
49 gal. per week
~196 gal. per
month