Presentation to HCMN class of 2012

1. Living off Rainwater, Even in a
Drought
Steve and Betty Clyburn
Texas Master Naturalist – Hill Country
Chapter
October 24, 2012

2. “Water is the driving force in
nature.”
― Leonardo da Vinci

3. The prime root causes of most
wars:
• Race
• Religion
• Resources (water, food, fuel)
"Whiskey is for drinking; water is for fighting
over” – Mark Twain

4. 1) WHY COLLECT RAINWATER
2) HISTORICAL
3) THE COMPONENTS OF A RAINWATER
HARVESTING SYSTEM WORK
4) WATER QUALITY
5) HOW MUCH WATER DO YOU USE?
6) HOW MUCH WATER CAN YOU
COLLECT?
7) CODE AND SAFETY ISSUES
8) COST CONSIDERATIONS
9) CONSERVATION

5. How Much Water is Available
~70% of our Planet is Water

7. “When the well is dry, we learn
the worth of water.”
Benjamin Franklin, Poor Richard's
Almanac (1746?)

8. Historical
Rainwater harvesting has been
around for thousands of years.
One resource can date rainwater
harvesting tanks back to 2600 BC
in India.

9. Portuguese Cistern of El Jadida in
Morocco. Circa 1542

10. Cisterna Basilica Junto a Santa
Sofia Istanbul6th Century CE

11. Rainwater Harvesting Tank – India
Gravis

12. Carrington-Couvert House
Austin TX ~1857

13. Why would Anyone In their Right Mind
Want to Collect Rainwater?
• Conserve water resources to help
preserve water levels in the aquifer
• Superior water quality – softer water
means less detergent, no lime/calcium
buildup on shower walls and appliances
• Plants and landscape prefer rainwater
• May be more dependable than a well
• Save money if using city water –
30-50% of total water used by a typical
home is for landscape watering
• No chemicals or additives necessary

14. Why would Anyone In their Right Mind
Want to Collect Rainwater?
• 90+% of rain evaporates
• To avoid drilling a well.
• To be able to water plants during water
restrictions.
• Does not require a water softner
• By using rainwater you can limit storm water
pollution by catching water that would
otherwise wash over land, streets, cow
pastures and into waterways.

16. Circa 1800’s

17. Catchment Surface
• Rainwater harvesting can be done with any
roofing material if it is only for non-drinking use.
• For potable use, the best roof materials are
metal, clay, and cement although all roof
material types have been used(except
asbestos). Asphalt shingles can contribute grit to
the system and need a pre-filter for the water
before it enters the cistern. Lead materials in any
form should not be used in the system (i.e. lead
flashing and soldered joints).

18. Barn Roof for Water Catchment
3,300 SQF

20. 200 Meter Rainwater Harvesting Tower
Chile

21. Water harvesting structure utilizing condensation,
Trans-en-Provence, France. Circa 1927

22. How Much Water Can I Catch?
• 0.623 gallons per square foot of roof per inch
of rain (Roof area calculated from parimeter
of roof – slope of roof is not considered)
• A one inch rain falling on 1000 sq ft of roof
area will give you 623 gallons.
• A 3,300 sq ft roof captures 2055 gallons for
every inch of rain…..in an average rain year
(28”s) that would be about 57,500 gallons!

23. Gallons Collected per Square Feet of Roof Area
for 0ne Inch of Rainfall
3500
Gallons per 1 inch of Rain
3000
2500
2000
1500
1000
500
0
0 1000 2000 3000 4000 5000 6000
Square Feet of Catchment Area

24. Conveyance to Storage

26. Conveyance to 2 X 20,000 Tanks

27. Initial Filtration/First Wash

30. First Wash System – rain barrel

31. First Wash System – the Eliminator
Tank Town
Cost ~$1200

32. First Wash System – Filtration
box
Fiberglass box with removable filters – $600-$800

33. Wisy Vortex Filter

34. First Wash System –
Wisy Vortex Filter

35. Storage
Tanks/Cisterns

36. Should have
• Cover to prevent mosquito breeding and
algae growth due to sunlight
• Inlet - generally at the top
• Outlet - ~ 6” above floor of tank
• Overflow - larger than inlet and
screened
• Bottom drain valve for cleaning
• Covered man way - 24”
• System to prevent agitation of the tank
while it is filling to minimize the stirring of
any settled solids in the bottom of the tank.
• Two or more tanks permit servicing one of
the units without losing the operation of the
system.

38. Polyethylene tanks

39. Fiberglass

40. Galvalum w/ vinyl liner
Pioneer tanks from Australia

45. Conveyance to Purification or End
Use

46. Quick-Connect Valve for Firetruck

47. Grundfos MQ Constant Pressure
Pump
~$575

48. Shallow Well Jet Pump 1 HP
w/ Pressure Tank

49. Jim Stanley

50. Purification

51. Filters

53. UV light
UV Light has been used for disinfection since the 1900,s
and has now become common practice in public utilities

56. Pump, Filtration and UV Light
~$2000

58. http://www.rainwatermanagement.com/

59. Digital Tank Volume

60. What happens if it doesn’t rain?

61. How Much Water Do I Need?
• It is important that the system is sized to
meet the water demand throughout the dry
season. In general, the size of the storage
tank should be big enough to meet the
daily water requirement throughout the dry
season. In addition, the size of the
catchment area or roof should be large
enough to fill the tank.

62. Kerrville Average Monthly Rainfall
~Average 28” per Year

63. Kerrville Rainfall – 8 years
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
2005 2.86 2.80 1.66 1.46 4.63 1.24 2.75 2.03 3.27 1.91 1.91 0.00 26.52
2006 1.02 0.55 1.87 1.49 4.41 1.08 1.30 0.11 5.25 3.00 0.07 1.41 21.56
2007 3.27 0.11 9.65 2.42 9.81 7.68 6.91 6.05 2.76 1.02 1.06 0.36 51.10
2008 0.44 0.19 2.40 1.88 1.69 0.50 1.82 2.84 0.47 2.17 0.09 0.23 14.72
2009 0.62 0.05 3.70 2.96 2.32 0.97 2.80 0.24 9.21 5.27 3.29 1.29 32.72
0.8 0.0 0.9
2010 3.21 2.88 2.50 3.94 1.88 3.86 4.78 0.04 5.16 4 6 8 30.13
1.3 0.5 0.0 0.9 1.1 0.7 0.1 0.2 2.0
2011 0 6 7 4 7 8 6 1 6 0.79 2.06 3.00 13.10
2012 2.30 2.10 3.75 0.00 4.35 0.17 2.00 0.75 3.80 1.60 20.82
2005-2011 Avg 1.88 1.16 3.20 1.89 3.78 2.04 2.82 1.53 4.00 2.08 1.22 1.04 26.33

64. How Much Do I Need to
Collect?
• Figure approximately 50-75 gallons per day per
person
• For 2 people: 3000-4500 gallons/month requires
an average of 1”-1½” rain/month
• 25,000 gallons = 7-8 month supply
• 1996 – summer 2011: never below 14,000 gallons
• To calculate capacity needed, figure on historic
maximum number of days with no rain

65. Clyburn Rainfall vs. Storage
Rain in Inches Gallons in Tanks Linear (Gallons in T
3 40000
35000
2.5
30000
2
25000
1.5 20000
15000
1
10000
0.5
5000
0 0
Nov-11
Jun-11
Jun-12
Aug-11
Aug-12
Jan-12
May-12
Sep-11
Dec-11
Mar-12
Jul-12
Sep-12
Jul-11
Feb-12
Oct-12
Oct-11
Apr-12

66. Emergency Backup Plan
• What to do if you lose all of your water?
Drought
Line Break or Leak
Contamination
• Where do you get water?
Well
River, Stream or Lake
Neighbor
How do you transport
Purchase Truck Load

67. Water Quality?
Is Rainwater Really OK to Drink?
• 25-micron fiber sediment filter
• 1-5 micron fiber sediment filter
• UV light
• pH 6.0 – 7.0
• Testing for Heavy Metals, E coli and coli-
form testing available through UGRA

69. Stephen F Austin Univ.
Data from 5337 Fiedler Rd Storage Tank

70. Commercial Applications
(All for Irrigation Only)
• Riverside Nature Center 10,000 gallon system
collecting off ~4,500 sq ft – takes only a 4” rain to
fill
• Hunt School District – 20,000 gallons
• Willow City Volunteer Fire Department –24,000
gallon system: gravity flow dispensing system
can fill a 400-gal tank on a brush truck in 2
minutes
• Lady Bird Johnson Wildflower Center in Austin –
70,000 gallons
• Peterson Memorial Hospital – 130,000 gallons
• Kroc Center in Kerrville – 135,000 gallons
• Boerne Champion High School – 224,250

76. Cost of Rain Water Harvesting
Components
• Technology:
• Fairly well-developed; new products are being
developed. Rainwater harvesting is an old
tradition practiced in all parts of the world
including Texas.
• COST:
• Rainwater harvesting systems are costly
compared to a city hookup. Compared to a well,
they are approximately equal

77. Clyburn Rainwater Collection System
Brand Where 2005 Cost
Whitaker
2 20,000 gal tanks Pioneer Tanks $16,130.00
Pump and pressure Home
1 tank Flotec Depot $419.00
UV purification
1 system Wedeco Internet $800.00
Pre Filtration
Equipment WISY Austin RW $814.00
Cartridge Filter
system
And 1u and 25u Big Blue
filters Type Internet $150.00
Plumbing parts Ferguson's $1,000.00
Total Rainwater Costs $19,313.00

78. Maintenance
• Monitor tank levels - weekly
• Inspect tanks for light leaks - monthly
• Clean first wash system after each major rain
• Measure pH or buffer tank water with baking
soda – after major rain
• Change filters quarterly/annually as needed
~$25/yr
• Clean gutters as needed with mild bleach –
annually
• Replace UV bulb every 12-14 months ~$100
• Sample water to certified test lab ~annually ~
$20

79. PUBLIC ACCEPTANCE:
.
• In the Hill Country area, there are is an
increasing number of rainwater harvesting
systems.
• A small segment of the population desires
rainwater catchment systems for indoor water
use.
• A larger portion of the population feels there is
an advantage of using captured rainwater for
irrigation.

80. REGULATORY:
• At present, there is no Texas regulation for rainwater for
indoor or outdoor household use unless the system is
backed up by publicly supplied waterlines. If a backup
system is used, to avoid any cross-connection, an airgap
must exist between the public water and rainwater. (An
example is a city water line feeding into a rainwater
cistern.) This airgap must exceed two diameters of the
city line in width.
• The Health Department will require that the rainwater
system does not contribute to mosquito breeding by
having an uncovered cistern.

81. Conservation

83. Ways to Conserve Water
• Check all faucets, pipes and toilets for leaks.
• Take shorter showers.
• Install water saving showerheads and ultra-low-flush toilets.
• Turn off the water while brushing teeth or shaving.
• Rinse vegetables in a full sink or pan of water.
• Fully load dishwasher.
• Rinse dishes in a full sink or pan of water.
• Wash full loads of clothes.
• Waiting for hot water (hot water recirculation loop or water
heater at point of use)
• Plant drought tolerant plants

84. HOW MUCH WATER DO WE USE
Non-Conserving Pre 1992 Current Conserving w/Efficient
80 – 100 gallons per day per Appliances
person 30-50 gallons per day per person
Shower Old shower head 2.2 GPM @ 60PSI Limit
(5 minutes) 30 gallons 9-11 gal per shower
Toilet Flushing Conventional toilet Ultra-low flush toilet 0.9 -1.5
4-7 gallons per flush gallons per flush
Brushing Teeth Tap running - 10 gallons Wet brush, rinse briefly
1 cup or less
Tub Bath Full - 20 gallons Minimal water level
Less than 10 - 15 gallons
Tap running - 2 gallons or Fill basin
Shaving more ½ -1 gallon
(Running Water Till Hot)
Washing Hands Tap running - 2 gallons or Soap and rinse
more 1 gallon or less
Dishwashing Tap running - 30 gallons Wash and rinse in sink
5 gallons
Automatic 1.6 – 2.9 GPL
Dishwasher Full cycle - 15 gallons Do not rinse dishes before
putting in dishwasher
Washing Full cycle, top water level 13 – 15 GPL
Machine - 40 gallons

85. Fountain/Birdbath

86. Evaporates ~ 5 gallons/day in summer

87. The Fix

88. Grey Water Collection Irrigation System

89. References
The Texas Manual on Rainwater Harvesting - Texas Water ...
www.twdb.state.tx.us/.../rainwaterharvestingmanual_3rdedition.pdf
Rainwater Harvesting
rainwaterharvesting.tamu.edu/
Rainwater Harvesting for Drylands and Beyond by Brad Lancaster
www.harvestingrainwater.com/
Tank Town - Rainwater Collection Since 1994!
www.rainwatercollection.com/
The Rainwater Harvesting Community : HarvestH2o.com
www.harvesth2o.com/
RAINWATER HARVESTING MANUAL - Virginia Department of ...
www.dcr.virginia.gov/documents/stmrainharv.pdf
Harvested Rainwater
Sustainable Sources: 18 years of online Green Building information
http://rainwater.sustainablesources.com/

91. •
Present Day
Currently in China and Brazil, rooftop rainwater harvesting is being practiced
for providing drinking water, domestic water, water for livestock, water for
small irrigation and a way to replenish ground water levels. Gansu province in
China and semi-arid north east Brazil have the largest rooftop rainwater
harvesting projects ongoing.
• In Bermuda and U.S. Virgin Islands the law requires all new construction to
include rainwater harvesting adequate for the residents.
• In the United Kingdom water butts are often found in domestic gardens to
collect rainwater, which is then used to water the garden. However, the
British government's Code For Sustainable Homes encourages fitting large
underground tanks to new-build homes to collect rainwater for flushing toilets,
washing clothes, watering the garden, and washing cars. This reduces by 50%
the amount of mains water used by the home.
• Until 2009 in Colorado, water rights laws almost completely restricted
rainwater harvesting; a property owner who captured rainwater was deemed
to be stealing it from those who have rights to take water from the watershed.
Now, residential well owners that meet certain criteria may obtain a permit to
install a rooftop precipitation collection system (SB 09-080).[6] Up to 10 large
scale pilot studies may also be permitted (HB 09-1129).[7] The main factor in
persuading the Colorado Legislature to change the law was a 2007 study that
found that in an average year, 97% of the precipitation that fell in Douglas
County, in the southern suburbs of Denver, never reached a stream—it was
used by plants or evaporated on the ground. In Colorado you cannot even drill
a water well unless you have at least 35 acres.
• In New Mexico, rainwater catchment for irrigation is mandatory for new
dwellings in Santa Fe.[8]
• In Australia rainwater harvesting is typically used to supplement the
household mains supply. In south east Queensland, households that harvested
rainwater doubled each year from 2005 to 2008, reaching 40% penetration at
that time (White, 2009 (PhD)).