Post on 11-Jan-2016
Western Water Workshop
Front Range Groundwater: Scarcity and Opportunity
July 21, 2010
Topics for Presentation
What problem?The inevitability of groundwater
dependenceConservation as an answerA portfolio approachInfrastructure
Where to next?Storage for future useThe public policy dilemma
Why Groundwater?
Woodmoor’s Raw Water System DevelopmentHistorical Perspective
Woodmoor’s Raw Water System DevelopmentHistorical Perspective
• Why non-tributary groundwater?– No accessible surface water provider– Readily available – Valuable resource– Develop incrementally – Relatively low cost for initial development – Protected from contamination– Drought resistant
• Groundwater is not “running out” but will cost more as groundwater levels continue to decline
• More wells, more energy needed to pump at deeper levels, reduction in well yield, and higher maintenance costs
Dawson: 50 – 150 gpm700 ft total depth
Denver: 50 – 250 gpm1300 ft TD
Denver Basin AquifersDenver Basin Aquifers•Interbedded Sandstone, Shale and Clay Aquifers
Arapahoe: 200 – 500 gpm1900 ft TD
Laramie-Fox Hills: 75 – 150 gpm (projection) 2500 ft TD
Source: USGS HA-730-C
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Groundwater dependent communities on the Front Range
What Problem?
100 year theoretical life of the aquifer
The practical life is 30 to 40 years
Source: Colorado Foundation for Water Education
NEIGHBORHOOD NEIGHBORHOOD DRAWDOWNDRAWDOWN
DWSD 8
Some simple math
A single family home needs about one-half acre-foot of delivery
The aquifer (all 4 layers) holds about 1.5 acre-feet of water per acre
Land density is about 3.5 units per acre.
At build-out, the water needed is 1.65 acre-feet per acre USING ALL 4 AQUIFERS!
Demand vs. SupplyDemand vs. Supply
Service Area Build-out
EFFECTS OF GROWTHEFFECTS OF GROWTH
DWSD 9
DWSD 10
FULL FULL GROWTHGROWTH
KEY KEY FINDINGSFINDINGS
Total Gross Gap: 28,600 – 28,752 AF
Counties with largest gap: El Paso (unincorporated):
22,600 AF Increased demand: 9,250 AF Loss of existing groundwater
supplies: 13,350 AF Lake: 1,950 AF
Increased demand- Unincorporated areas
Arkansas Basin Consumptive
Use Water Needs Assessment
Arkansas Basin Roundtable
Conservation
Seasonal variation and daily peakA water manager has to meet
bothPeaking on a deep aquifer well
stresses the aquifer further reducing well yield
Residential Water UseResidential Water Use
Outdoor40%
Other4%
Washer13%
Faucet9%
Toilet15%
Leaks8%
Shower & Bath11%
2005 Annual Hydrograph2005 Annual Hydrograph
14.33%
56.74%
62.28%
66.45%
56.36%
47.95%
25.03%
0.0
10.0
20.0
30.0
40.0
50.0
60.0M
on
thly
De
ma
nd
(M
illio
n G
allo
ns
)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Outdoor
Indoor
Indoor / Winter Demand
Irrigation / Summer Demand
Managed Peak Day DemandManaged Peak Day Demand
0
1
2
3
4
5
6
12:0
0 A
M
1:00
AM
2:00
AM
3:00
AM
4:00
AM
5:00
AM
6:00
AM
7:00
AM
8:00
AM
9:00
AM
10:0
0 A
M
11:0
0 A
M
12:0
0 P
M
1:00
PM
2:00
PM
3:00
PM
4:00
PM
5:00
PM
6:00
PM
7:00
PM
8:00
PM
9:00
PM
10:0
0 P
M
11:0
0 P
M
Time
Dem
and
(M
GD
)
20% - Peak Reduction
Conservation/Demand Management Programs Passive Conservation
Conservation/Demand Management Programs Passive Conservation
• Information/Education– Bill Stuffers– Articles– Water-Wise Garden Open House– New “Product” Exhibit – “Green Builders” BMPs – Water Use Audit Programs
• Demand Reduction – Annual Demands 5 % - 10%– Max Day Demands 5 % – 10%
Conservation/Demand Management Programs Active Demand Management
Conservation/Demand Management Programs Active Demand Management
– Reduction of Unaccounted for Water– Rebates– Designated Watering Days (max-day)– Designated Watering Hours (annual demand) – Budget Billing– Conservation Rates– “Water Conservation” Building Codes
• Demand Reduction– Annual Demand 10% - 15%– Max Day Demand 15% - 25%
Conservation/Demand Management Programs Restrictions
Conservation/Demand Management Programs Restrictions
– Turf Limitations – size – type
– Punitive price/rates structures
– Landscape Designs Review and Approval
– Irrigation System Review and Approval
– Limit Designated Watering Days (max-day)
– Limit Designated Watering Hours (annual demand)
– Budget Billing – reduce budgets – increase rates
• Demand Reduction– Annual Demands 15% - 35%
– Max Day Demands 25% - 40%
2007 Summer Water Use Program(June 1st. through September 1st.)
2007 Summer Water Use Program(June 1st. through September 1st.)
Common Elements• Outdoor Use Calendar
– Odd # address Sunday, Wednesday, Friday– Even # address Saturday, Tuesday, Thursday– NO watering on Monday
• Prohibited Watering Hours– No Watering 10 am to 6 pm
• Water Waste – It is a violation to waste water by causing runoff of water
on streets or into drainage facilities
2007 Summer Water Use Program(June 1st. through September 1st.)
2007 Summer Water Use Program(June 1st. through September 1st.)
Outdoor Watering & Irrigation• Turf Grass
– 3 times per week per calendar • New Seed & Sod
– Lawn permits from District - additional irrigation times allowed - 2 week permit for sod - 4 week permit for seed
• Flowers, Vegetables, Trees and Shrubs – Hand-held hose or low-volume non-spray irrigation, any day, any
time. • Designated Community Parks, open space and Athletic
& playing fields– Water Budget developed with the District
A Portfolio Approach
Conservation is fundamentalDo you issue a new tap on conserved
water?Demand Harding
The Yuck FactorIndirect Potable ReuseThe Space Shuttle model
Groundwater remains in the portfolio
ExchangeExchangeConserve.Conserve.
SurfaceWater
SurfaceWater
Integrated Supply Strategy Integrated Supply Strategy
Ground-water
Ground-water ExchangeExchange Conser-
vation
Conser-vation
DEMAND
DEMAND
Current Future
Ground-water
Ground-water ExchangeExchange
Ground-water
Ground-water
SurfaceWater
SurfaceWater
Current Future
Infrastructure
Delivery infrastructure is expensive
The remaining sources are not where the customers are located
Is this speculation?
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Infrastructure Development:
Well Field
The wells will be grouped into pods and developed in phases to minimize up front capital costs.
The development of the well field includes down hole drilling, power hook up and collection piping.
The well field will include between 20 and 35 wells drilled at depths of 1,500 to 2,800 feet.
There is a substation on the southeast side of the ranch reducing the costs of power hook up.
A collection network of 8” – 20” pipe will be constructed over a phased period as market demand comes on line.
Pump station and electrical transmission infrastructure development costs are included in the well field development costs.
Estimated net present value of the well field development costs range from $29 million to $41 million based upon sales scenario.
All Rights Reserved © West Water Research Confidential and Proprietary Information
Infrastructure Development:
Conveyance (cont.)
Brown and Caldwell has prepared initial pipeline route and cost estimates.
The routes and pipe size were selected based upon the four most likely demand scenarios.
The pipeline route heading south consists of 9 miles of 16” to 24” inch diameter pipe.
The pipeline routes heading north consist of 12 to 26 miles of 16” to 24” inch diameter pipe.
Pressure reducing facilities and pump station costs are included in conveyance cost estimates.
Estimated net present value of the conveyance costs range from $23 million to $45 million based upon sales scenario.
Groundwater Dependence
The Denver Basin AquifersRate of
depletion
Future sources of supply?
The Denver Basin USGS Study: 2008
Groundwater Dependence
Designated BasinsA Modified
Prior Appropriation Doctrine (Groundwater Act of 1965)
Management Districts
Source: Division of Water Resources
2007:A Two Pronged Approach
Base study of the Upper Black Squirrel Designated Groundwater BasinColorado Geologic Survey, Dec, 2008
A Public Policy Forum sponsored by the Arkansas Basin Roundtable (Sept, 2007)Peer Review by the Director of
Natural Resources, Dec, 2008
Alluvial aquifer east of Colorado Springs
Lying atop a bedrock layer of Pierre shale
Depletion began in the 1960’s
1964 to 2004 well depletion
s
Description Total Area (acres)
Total Storage Capacity (ac-ft)
Total Saturated Primary Alluvium 78,850 474,643
Total Unsaturated Primary Alluvium 78,850 605,865- Unsaturated Alluvium (50ft-water
table)38,000 218,327
- Unsaturated Alluvium (75ft-water table)
20,250 88,164
- Unsaturated Alluvium (100ft-water table)
8,540 25,996
Upper Black Squirrel Creek BasinAlluvium Storage Calculations* Using a storage coefficient of 0.18
Designated Groundwater
Conference in Sept, 2007
http://ibcc.state.co.us/News/
Conflicting Conclusions
The legal system is working just fine
One at a time legal cases are very expensive
Recharge for Future Use
Recharge as augmentation is not recharge for future storage
Rules in the Denver Basin by SEO
A National Issue
National Academy of Sciences MUS study
EPA Experts Meeting May 5-6, 2009
Where do we go from here?
How do quantity and quality work together?
How will the State permit projects?
A pilot by the General Assembly?
Where do we go from here?
Source: DNR Director Harris Sherman, Dec, 2008
Opportunity?
Can we collaborate before we reach a crisis?
Can the Prior Appropriation Doctrine accommodate the future of Colorado’s water resources?The River of 1890Groundwater is tributary until you prove
a negative, i.e. non-injuryIs the legislature the appropriate
venue to change groundwater policy?