Presentation on theme: "Western Water Workshop Front Range Groundwater: Scarcity and Opportunity July 21, 2010."— Presentation transcript:
Western Water Workshop Front Range Groundwater: Scarcity and Opportunity July 21, 2010
Topics for Presentation What problem? The inevitability of groundwater dependence Conservation as an answer A portfolio approach Infrastructure Where to next? Storage for future use The public policy dilemma
Woodmoor’s Raw Water System Development Historical 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 gpm 700 ft total depth Denver: 50 – 250 gpm 1300 ft TD Denver Basin Aquifers Interbedded Sandstone, Shale and Clay Aquifers Arapahoe: 200 – 500 gpm 1900 ft TD Laramie-Fox Hills: 75 – 150 gpm (projection) 2500 ft TD Source: USGS HA-730-C
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!
KEY FINDINGS 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 peak A water manager has to meet both Peaking on a deep aquifer well stresses the aquifer further reducing well yield
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 –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 –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.) 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.) 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 fundamental Do you issue a new tap on conserved water? Demand Harding The Yuck Factor Indirect Potable Reuse The Space Shuttle model Groundwater remains in the portfolio
Exchange Conserve. Surface Water Integrated Supply Strategy Ground- water Exchange Conser- vation DEMANDDEMAND DEMANDDEMAND CurrentFuture Ground- water Exchange Ground- water Surface Water CurrentFuture
Infrastructure Delivery infrastructure is expensive The remaining sources are not where the customers are located Is this speculation?
Groundwater Dependence The Denver Basin Aquifers Rate of depletion Future sources of supply? The Denver BasinUSGS Study: 2008
Groundwater Dependence Designated Basins A 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 Basin Colorado 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
DescriptionTotal Area (acres)Total Storage Capacity (ac-ft) Total Saturated Primary Alluvium78,850474,643 Total Unsaturated Primary Alluvium78,850605,865 - Unsaturated Alluvium (50ft-water table)38,000218,327 - Unsaturated Alluvium (75ft-water table)20,25088,164 - Unsaturated Alluvium (100ft-water table)8,54025,996 Upper Black Squirrel Creek Basin Alluvium 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 1890 Groundwater is tributary until you prove a negative, i.e. non-injury Is the legislature the appropriate venue to change groundwater policy?