title slide an investigation funded through the innovative water strategies division of the texas...
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Title SlideTitle Slide
An investigation funded through theAn investigation funded through the
INNOVATIVE WATER STRATEGIES INNOVATIVE WATER STRATEGIES
Division of the Division of the
Texas Water Development BoardTexas Water Development Board
11
Research TeamResearch Team Meredith Blount Miller – Meadows Center Stacy Bray – Meadows Center David Venhuizen, P.E. – Venhuizen Water
Works Karen Ford – White Hat Creative
22
““Building-scaleBuilding-scale”” Systems Systems
Independent rainwater Independent rainwater harvesting system for each harvesting system for each
buildingbuilding
THETHE strategy for all buildings: strategy for all buildings:
not an optionnot an option
33
Collective O&M and Collective O&M and ASSURED backup supply ASSURED backup supply
systemsystem
44
Study Focus: Texas Hill Study Focus: Texas Hill CountryCountry
Photo Courtesy of Hill Country Alliance- 2012 Calendar Contest 55
Water Supply OptionsWater Supply Options
Private well Private well on each loton each lot
Community well Community well and water and water
systemsystem
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Water Supply OptionsWater Supply Options
Connect to area-wide water systemConnect to area-wide water system
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Water Supply OptionsWater Supply OptionsRegional pipelinesRegional pipelines
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Water Supply OptionsWater Supply Options
Rainwater HarvestingRainwater Harvesting!!!!
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1010
Why is a Why is a development-wide development-wide
rainwater harvesting rainwater harvesting SYSTEMSYSTEM
a good option?a good option?
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Rainwater Harvesting isRainwater Harvesting is
MORE EFFICIENTMORE EFFICIENT
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83% of rainfall onto the 83% of rainfall onto the Barton Springs watershed Barton Springs watershed
was lost to was lost to evapotranspiration, and evapotranspiration, and
never made it to a reservoir never made it to a reservoir or aquifer.or aquifer.
1313
Rainwater Harvesting isRainwater Harvesting is
MORE EFFICIENTMORE EFFICIENT
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Rainwater HarvestingRainwater Harvesting
““FITSFITS”” IN THE HILL COUNTRY IN THE HILL COUNTRY
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Rainwater HarvestingRainwater Harvesting
REDUCES UP FRONT COSTREDUCES UP FRONT COST
Developers should like this a Developers should like this a lot!lot!
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Rainwater HarvestingRainwater Harvesting
REDUCES FISCAL RISKREDUCES FISCAL RISK
Developers should like this a Developers should like this a lot!lot!
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Rainwater Harvesting isRainwater Harvesting is
UNDER THE USERS’ CONTROLUNDER THE USERS’ CONTROL
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Rainwater Harvesting isRainwater Harvesting is
MORE RELIABLEMORE RELIABLE
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Rainwater Harvesting isRainwater Harvesting is
MORE SUSTAINABLEMORE SUSTAINABLE
2020
Roof-harvested rainwater isRoof-harvested rainwater is
BETTER WATERBETTER WATER
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Water from wells and reservoirs is DEGRADED Water from wells and reservoirs is DEGRADED from quality of the original rainwater.from quality of the original rainwater.
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Rainwater HarvestingRainwater Harvesting
USES LESS ENERGYUSES LESS ENERGY
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Many reasons to consider Many reasons to consider building-scale RWH!building-scale RWH!
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Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
2525
The Modeling ProcessThe Modeling Process Simulate rainwater collection and use in Simulate rainwater collection and use in
househouse Shows Shows ““right sizeright size”” of RWH facilities of RWH facilities ““Right sizeRight size”” = size required for long-term = size required for long-term
sustainabilitysustainability Determined by backup supply requirementsDetermined by backup supply requirements ASSURED backup supply = RELIABILITYASSURED backup supply = RELIABILITY
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Rainwater Harvesting Rainwater Harvesting ModelModel
Average rainfall models inadequateAverage rainfall models inadequate Weather is not averageWeather is not average Multi-year modelMulti-year model Through wet and dry cyclesThrough wet and dry cycles Used 25-year model, 1987-2011Used 25-year model, 1987-2011 Covers the Covers the ““critical periodcritical period””
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Courtesy of John W. Nielsen-Gammon
Professor and Texas State Climatologist
Department of Atmospheric Sciences
28282828
Lowest 12-month rainfall Lowest 12-month rainfall totalstotals
1987-20111987-2011
29292929
Right-Size for OutlierRight-Size for Outlier 2010-2011 drought controls 2010-2011 drought controls ““right-right-
sizingsizing”” Outlier Outlier Very infrequent Very infrequent Right-sized for any future conditionsRight-sized for any future conditions Reliable and sustainableReliable and sustainable
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31313131
32323232
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RoofprintRoofprintRoof area off of which rainwater is collectedRoof area off of which rainwater is collected
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Roofprint is the plan Roofprint is the plan area of the ROOF, all area of the ROOF, all
the roof, NOT the the roof, NOT the HOUSE areaHOUSE area
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Interior Water UseInterior Water Use
3636
Interior Usage Rate for Interior Usage Rate for RWHRWH
35 gpcd – presumed by RWH designers35 gpcd – presumed by RWH designers Is this reasonable?Is this reasonable?
100 gpcd – 100 gpcd – ““StandardStandard”” rate for rate for ““conventionalconventional”” water system planning water system planning
This is NOT residential INTERIOR water useThis is NOT residential INTERIOR water use
gpcd = gallons per capita (person) per daygpcd = gallons per capita (person) per day
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Water usage used for design Water usage used for design of on-site wastewater of on-site wastewater
systemssystems 60 gpcd with 60 gpcd with ““conservingconserving”” fixtures fixtures Actual water use observed to be Actual water use observed to be
~50 gpcd~50 gpcd
3838
Fixture/Use Unit Demand Usage Rate Water Use (gpcd)
Toilets 1.5 gal/flush 4 flush/person/day 6.0
Showers 1.9 gal/min. 4.8 min/person/day 9.1
Washing machine 42 gal/load 0.3 load/person/day 12.6
Dishwasher 8.5 gal/load 0.17 load/person/day 1.4
Faucets estimated estimated 8.5
Baths 50 gal/bath 0.14 bath/person/day 7.0
Total Water Use = 44.6
Household Water Usage Rates with Latest State-of-the-Art FixturesAWWA Study, circa 1990
3939
Total Water Use Average Daily Average Daily WaterY ear (gallons) Water Use (gpd) Use per Person (gpcd)
2003 32,457 88.9 22.2
2004 34,361 93.9 23.5
2005 33,840 92.7 23.2
2006 32,007 87.7 21.9
2007 35,529 97.3 24.3
2008 34,482 94.2 23.6
2009 38,544 105.6 26.4
2010 41,118 112.7 28.2
2011 36,174 99.1 24.8
9-year avg. 35,390 96.9 24.2
Rainwater Harvesting System Water Use History4-Person Household, 2 Adults, 2 Children
4040
Usage Rates in RWH Usage Rates in RWH ModelModel
50 gpcd – 50 gpcd – ““defaultdefault”” rate rate 45 gpcd and 40 gpcd – better demand control45 gpcd and 40 gpcd – better demand control
4141
Modeled Household Modeled Household OccupanciesOccupancies
2-person occupancy2-person occupancy ““Empty-nestersEmpty-nesters””/seniors/seniors
4-person occupancy4-person occupancy ““StandardStandard”” 3-bedroom house, likely 3-bedroom house, likely
the bulk of the bulk of ““normalnormal”” subdivision subdivision marketmarket
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Irrigation Water UseIrrigation Water Use
4343
Wastewater Reuse for Wastewater Reuse for IrrigationIrrigation
4444
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Modeling Results SummaryModeling Results Summary
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Example Example Modeling ResultsModeling Results
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Dripping SpringsDripping Springs
Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 4,500 sq. ft.sq. ft.
Cistern capacityCistern capacity 35,00035,000 gallons gallons
OccupancyOccupancy 4 4 persons persons
Water usage rateWater usage rate 5050 gpcd gpcd
Backup supply requirementsBackup supply requirements1996 1996 2,000 gallons 2,000 gallons
2008 2008 4,000 gallons 4,000 gallons
2009 2009 14,00014,000 gallons gallons
2011 2011 18,00018,000 gallons gallons
Total = Total = 38,000 gallons38,000 gallons4848
Dripping SpringsDripping Springs
Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 sq. ft. 4,500 sq. ft.
Cistern capacityCistern capacity 35,00035,000 gallons gallons
OccupancyOccupancy 4 persons 4 persons
Water usage rateWater usage rate 45 gpcd45 gpcd
Backup supply requirementsBackup supply requirements2009 2009 4,000 gallons 4,000 gallons
2011 2011 10,00010,000 gallons gallons
Total = Total = 14,000 gallons14,000 gallons
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Dripping SpringsDripping Springs
Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 sq. ft. 4,500 sq. ft.
Cistern capacityCistern capacity 35,000 gallons35,000 gallons
OccupancyOccupancy 4 persons 4 persons
Water usage rateWater usage rate 40 gpcd40 gpcd
Backup supply requirementsBackup supply requirements2011 2011 2,0002,000 gallons gallons
Total = Total = 2,000 gallons2,000 gallons
5050
Dripping SpringsDripping Springs
Interior + Irrigation UsageInterior + Irrigation UsageWITHOUT wastewater reuseWITHOUT wastewater reuse
RoofprintRoofprint 4,5004,500 sq. ft. sq. ft.
Cistern capacityCistern capacity 35,00035,000 gallons gallons
OccupancyOccupancy 4 persons 4 persons
Interior usage rateInterior usage rate 50 gpcd 50 gpcd
Irrigated area Irrigated area 2,4002,400 sq. ft. sq. ft.
Backup water supply required in Backup water supply required in 13 years13 years
Max. yr. = Max. yr. = 58,00058,000 gallons in 2011 gallons in 2011
22ndnd most = most = 40,00040,000 gallons in 1996 gallons in 1996
33rdrd most = most = 38,00038,000 gallons in 2008 gallons in 2008
Total over 25 years = Total over 25 years = 268,000268,000 gallons gallons
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Dripping SpringsDripping Springs
Interior + Irrigation UsageInterior + Irrigation UsageWITHOUT wastewater reuse, larger systemWITHOUT wastewater reuse, larger system
RoofprintRoofprint 7,0007,000 sq. ft. sq. ft.
Cistern capacityCistern capacity 50,00050,000 gallons gallons
OccupancyOccupancy 4 persons 4 persons
Interior usage rateInterior usage rate 50 gpcd 50 gpcd
Irrigated area Irrigated area 2,4002,400 sq. ft. sq. ft.
Backup supply requirementsBackup supply requirements
2009 2009 6,000 gallons 6,000 gallons
2011 2011 28,00028,000 gallons gallons
Total = Total = 34,000 gallons34,000 gallons5252
Dripping SpringsDripping Springs
Interior + Irrigation UsageInterior + Irrigation UsageWITH wastewater reuseWITH wastewater reuseRoofprint Roofprint 4,500 sq. ft.4,500 sq. ft.
Cistern capacityCistern capacity 35,000 gallons35,000 gallons
OccupancyOccupancy 4 persons 4 persons
Interior usage rateInterior usage rate 50 gpcd 50 gpcd
Irrigated area Irrigated area 2,4002,400 sq. ft. sq. ft.
Backup supply requirementsBackup supply requirements
19961996 2,000 gallons 2,000 gallons
2008 2008 6,000 gallons 6,000 gallons
2009 2009 14,00014,000 gallons gallons
2011 2011 22,00022,000 gallons gallons
Total = Total = 44,000 gallons44,000 gallons5353
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
5454
Options for Backup Supply Options for Backup Supply SystemSystem
A private well for each A private well for each buildingbuilding
Community well, Community well, ““minimaminimall”” distribution system distribution system
Community well + Community well + tanker truck tanker truck
deliverydelivery
Connection to Connection to existing PWS existing PWS
systemsystem
Tanker truck delivery Tanker truck delivery from potable water from potable water
supplysupply
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Tanker TrucksTanker TrucksSupplied by Public Water Supplied by Public Water
SystemSystem Likely to be predominant methodLikely to be predominant method Favored by developers – no up front Favored by developers – no up front
costscosts Regulatory issues – requirement for Regulatory issues – requirement for
ASSURED supply?ASSURED supply? How formalized?How formalized? What will it cost to set up?What will it cost to set up?
5656
Tanker TrucksTanker TrucksSupplied by Public Water Supplied by Public Water
SystemSystem Conditions of service for guaranteed supplyConditions of service for guaranteed supply Cost of guarantee?Cost of guarantee? Commercial hauler, or utility/HOA truckCommercial hauler, or utility/HOA truck Supply capacity, number of trucks availableSupply capacity, number of trucks available Regulatory statusRegulatory status Backup requirement must be very limitedBackup requirement must be very limited
5757
Tanker trucksTanker truckssupplied by a public water supplied by a public water system REQUIRE that you system REQUIRE that you hold backup supply to low hold backup supply to low
levels.levels.
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Tanker Truck System:Tanker Truck System:Capacity LimitationsCapacity Limitations
Development with 100 housesDevelopment with 100 houses 1 House = 1 Truck / 1 House = 1 Truck / MonthMonth1 House = 1 Truck / 1 House = 1 Truck / MonthMonth
= 100 Trips / Month= 100 Trips / Month= 100 Trips / Month= 100 Trips / Month5959
Tanker Truck System:Tanker Truck System:Capacity LimitationsCapacity Limitations
22 working days in a month100/22 = 4.5 truck trips per day
One tanker truck, full time
for one development!
22 working days in a month100/22 = 4.5 truck trips per day
One tanker truck, full time
for one development! 6060
Is the private sector ready Is the private sector ready for this kind of demand?for this kind of demand? Ability to meet intermittent demandAbility to meet intermittent demand Ability to expand fleet as number of Ability to expand fleet as number of
developments growsdevelopments grows Further investigation neededFurther investigation needed
6161
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
6262
TCEQ RegulationsTCEQ Regulations Regulatory status of development-Regulatory status of development-
wide RWH strategywide RWH strategy Rules under considerationRules under consideration Rules for backup supply strategiesRules for backup supply strategies Rule interpretations for RWH Rule interpretations for RWH
systems that systems that areare public water public water supply systemssupply systems
6363
Regulatory Status?Regulatory Status? Building-scale RWH systems currently unregulatedBuilding-scale RWH systems currently unregulated Would it be a Would it be a ““public water supply systempublic water supply system”” if: if:
Platted as THE water supply system the development?Platted as THE water supply system the development? Collective O&M of all RWH systems?Collective O&M of all RWH systems? Collective arrangements for backup supply?Collective arrangements for backup supply?
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Would this cause the Would this cause the TCEQ to consider TCEQ to consider
building-scale RWH a building-scale RWH a
“public water supply “public water supply system?”system?”
6565
Current understanding ofCurrent understanding ofTCEQTCEQ’’s positions position
Building-scale RWH system to remain Building-scale RWH system to remain unregulatedunregulated
Regulations being developed for RWH Regulations being developed for RWH systems with connection to public systems with connection to public water supply system on propertywater supply system on property
Regulatory status of tanker truck Regulatory status of tanker truck backup supply system needs backup supply system needs clarificationclarification
6666
Rule Interpretations for RWH Rule Interpretations for RWH that ARE Public Water Supply that ARE Public Water Supply
SystemsSystemsvillage centers, churches, community hallsvillage centers, churches, community halls
6767
Public Water Supply Public Water Supply SystemsSystems
Rule Interpretations for Rule Interpretations for RWHRWH
ChlorinationChlorination VSVS UV disinfection unit UV disinfection unit
6868
Are these practices Are these practices approved for building-scale approved for building-scale
systems?systems?
What would be the testing What would be the testing and reporting and reporting requirements?requirements?
Would they be affordable?Would they be affordable?6969
County-level GovernanceCounty-level GovernanceThrough Platting RequirementsThrough Platting Requirements
Rainwater Harvesting as Rainwater Harvesting as THE development-wide water SYSTEM – THE development-wide water SYSTEM –
what requirements would that generate?what requirements would that generate?
7070
County-level GovernanceCounty-level GovernanceThrough Platting Through Platting
RequirementsRequirements ““Water availabilityWater availability”” standards standards Water treatment standardsWater treatment standards Backup supply standardsBackup supply standards
7171
What does What does ““water water availabilityavailability””
require?require? ““Right-sizingRight-sizing”” of roofprint and of roofprint and
cisterncistern Backup supply system as Backup supply system as
determined by that system sizingdetermined by that system sizing
7272
Who sets the standards Who sets the standards for water availability?for water availability?
Commissioner’s Court?Commissioner’s Court? Developers?Developers?
7373
Outreach to County Outreach to County GovernmentsGovernments
““Chicken-or-eggChicken-or-egg”” conundrum conundrum Developers aren’t requesting plat approval Developers aren’t requesting plat approval
for this kind of water supply solution.for this kind of water supply solution. Therefore, no impetus for county Therefore, no impetus for county
governments to think through these matters.governments to think through these matters. Further outreach efforts are suggested:Further outreach efforts are suggested:
SurveysSurveys SeminarsSeminars Focus group workshopsFocus group workshops
7474
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
7575
“Right-Sized” RWH FacilitiesAt Each Modeling Location
2-Person Occupancy 4-Person OccupancyModeling Roofprint Cistern Size Roofprint Cistern SizeLocation (sq. ft.) (gallons) (sq. ft.) (gallons)
Austin
2,500
15,000
4,500
35,000
Blanco
2,500
15,000
4,500
35,000
Boerne
2,500
15,000
4,500
35,000
Burnet
2,500
15,000
4,500
30,000
Dripping Springs
2,500
15,000
4,500
35,000
Fredericksburg
3,000
20,000
5,000
40,000
Menard
3,000
20,000
5,500
40,000
San Marcos
2,500
15,000
4,500
30,000
Wimberley
2,500
15,000
4,500
30,000
7676
““Right-SizingRight-Sizing”” the theRoofprint and CisternRoofprint and Cistern
7777
The The ““Veranda StrategyVeranda Strategy””
Reduces solar Reduces solar load and air load and air conditioning conditioning requirementsrequirements
Creates outdoor Creates outdoor living spacesliving spaces
7878
7979
Bladder-type cistern that could Bladder-type cistern that could be placed under the veranda be placed under the veranda
floorfloor
8080
Additional Roofprint with the Additional Roofprint with the ““Veranda StrategyVeranda Strategy””
8181
Need Hill Country RWH Need Hill Country RWH Vernacular DesignsVernacular Designs
Business opportunity for architects?Business opportunity for architects? Design competitionDesign competition Student design studio projectStudent design studio project
8282
““Chicken or Egg” AgainChicken or Egg” AgainDevelopers need house designs that could Developers need house designs that could implement rainwater harvesting systems.implement rainwater harvesting systems.
8383
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
8484
Cost Effectiveness ofCost Effectiveness ofRWH vs. Other StrategiesRWH vs. Other Strategies
Compare Compare globalglobal life-cycle costs life-cycle costs Other strategies to be evaluated:Other strategies to be evaluated:
8585
Cost items for Cost items for
Building-scale RWH StrategyBuilding-scale RWH Strategy First CostsFirst Costs
““ExtraExtra”” roofprint roofprint Collection/first flush hardwareCollection/first flush hardware CisternCistern Treatment systemTreatment system Disinfection systemDisinfection system Pump/pressurization systemPump/pressurization system
On-going CostsOn-going Costs Power costsPower costs O&M, equipment replacementO&M, equipment replacement Backup water costsBackup water costs
8686
Summary and ComparisonSummary and ComparisonCosts of Water Supply OptionsCosts of Water Supply Options
8787
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
8888
Marketing Focus GroupMarketing Focus GroupThe marketing focus group included The marketing focus group included
members of the following interest members of the following interest groups:groups: Land developersLand developers HomebuildersHomebuilders ArchitectsArchitects Land planners and engineersLand planners and engineers Real estate brokersReal estate brokers Banker (home finance specialist)Banker (home finance specialist) Consumers (potential home buyers)Consumers (potential home buyers)
8989
What determines What determines
Marketability?Marketability?ASSURED backup supply ASSURED backup supply
availableavailable RWH-RWH-““friendlyfriendly”” house designshouse designs Regulatory Regulatory
clarityclarity
Cost Cost effectiveeffective
Readily available Readily available financingfinancing
9090
The BIG ONE – PerceptionThe BIG ONE – Perception
9191
““Conservation Ethic”Conservation Ethic”
9292
Will perception about Will perception about “deprivation” deter developers “deprivation” deter developers
from adopting RWH?from adopting RWH?
Education Key Factor for Education Key Factor for MarketabilityMarketability
Photo courtesy of ARCSA: http://www.arcsa.org/content.asp?contentid=194
9393
Overview of Project Overview of Project ActivitiesActivities
Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination
9494
Sustainability of Sustainability of DevelopmentDevelopment
““Development lives mainly on water falling on it.”Development lives mainly on water falling on it.”
9595
Long-Distance Water Long-Distance Water ImportationImportation
Photo courtesy of California Department of Water Resources
9696
““Conservation Development”Conservation Development”The Pattern Favored for the Hill The Pattern Favored for the Hill
CountryCountry
9797
Hydrologic SustainabilityHydrologic SustainabilityDoes RWH Does RWH ““robrob”” water from streams and aquifers? water from streams and aquifers?
World Birding Center Headquarters, photo courtesy Lake Flato Architects
9898
Hydrologic SustainabilityHydrologic Sustainability Strategy for analysis:Strategy for analysis:
Rainfall-runoff response of undeveloped siteRainfall-runoff response of undeveloped site Rainfall-runoff response of developed site, no RWHRainfall-runoff response of developed site, no RWH Rainfall-runoff response of developed site with RWHRainfall-runoff response of developed site with RWH
9999
Outcomes of Hydrologic Outcomes of Hydrologic ModelingModeling
Rainwater harvesting will NOT result in Rainwater harvesting will NOT result in decreased levels of runoff from the finished decreased levels of runoff from the finished development in comparison with the land in its development in comparison with the land in its ““rawraw”” state. state.
The addition of impervious cover other than The addition of impervious cover other than roofs – i.e., streets and driveways – and land roofs – i.e., streets and driveways – and land alterations – e.g., improved landscaping, alterations – e.g., improved landscaping, drainage structures – will result in a higher runoff drainage structures – will result in a higher runoff rate from all non-roof areas, more than making rate from all non-roof areas, more than making up for what is captured into rainwater cisterns.up for what is captured into rainwater cisterns.
100100
Hydrologic SustainabilityHydrologic Sustainability
101101
Hydrologic SustainabilityHydrologic SustainabilityRWH off rooftops in a development RWH off rooftops in a development
would would improveimprove the hydrological the hydrological integrity of the developed property.integrity of the developed property.
102102
For more information:For more information:
Texas Water Development BoardTexas Water Development Boardwww.twdb.texas.gov/innovativewater/rainwawww.twdb.texas.gov/innovativewater/rainwa
ter/ter/
Meadows Center for Water and the Meadows Center for Water and the EnvironmentEnvironment
Texas State UniversityTexas State Universitywww.rsihillcountrywater.org/rainwater-www.rsihillcountrywater.org/rainwater-
harvesting/harvesting/
David Venhuizen, P.E.David Venhuizen, P.E.venhuizen-ww.com
103103