WNHN Model Report v Key Features 150 miles
- Slides: 10
WNHN Model Report v Key Features ü 150 miles by 150 miles ü One-half mile uniform grid cells ü Five Layers: D, N, three for Carmel/Wanakah ü Steady State (>~1956) simulation ü Historical Transient (1956 -2000) simulation
WNHN Model Report v Natural Flow ü Recharge Components diffuse precipitation ü San Juan River on far NE edge ü ü Discharge and evaporation numerous seeps ü springs ü canyons ü ü Discharge to Colorado and San Juan Rivers
WNHN Model Report v Human-Imposed Flow Components ü Inflow/Outflow along Lake Powell south shore ü Pumping Peabody Western Coal Company ü Indian Municipal ü Windmills ü
WNHN Model Report v Model Parameters – ü D-Aquifer System Hydraulic Conductivity 0. 03 to 0. 2 ft/day for horizontal hydraulic conductivity ü 1/10 of horizontal for vertical hydraulic conductivity ü ü Carmel/Wanakah Aquitard 1 - 5 x 10 -3 ft/day for horizontal hydraulic conductivity ü 1 - 5 x 10 -7 ft/day for vertical hydraulic conductivity ü ü N-Aquifer System 0. 05 to 1 ft/day for horizontal hydraulic conductivity ü 1/10 of horizontal for vertical hydraulic conductivity ü
WNHN Model Report v Model Parameters – Storage ü Specific Storage – 10 -7 ft-1 ü Specific Yield – 0. 1
WNHN Model Report v Recharge ü 0. 5 percent of precipitation in lower-elevation, lower precipitation areas ü 3 -4 percent of precipitation on highest plateaus ü Bands of higher recharge around extensive laccoliths ü >90 loss to surficial and shallow ET addressed
WNHN Model Report v Evapotranspiration ü Extension of usual model simulation of ET ü Seeps, springs and small canyon flows evaporate in short order ü Direct evaporation and transpiration from water table is also simulated
WNHN Model Report v Calibration to steady state (<~1955) ü 377 data points ü Standard Deviation of Residuals (RSD) = 119 feet v Calibration 2000) to historical transient period (1956 - ü 2373 points from 37 wells ü RSD = 57 feet v Tabulations of Spring simulations yet to come
WNHN Model Report v v Current Status: v Report has been through preliminary review by HDR and USBR v Report out for review and comment by TSG Next Steps v Compile and evaluate TSG review comments v Run model with baseline (2000 continued) and most likely demand conditions v Evaluate key components determining response to pumping v v Drawdown v Impacts on POS Springs Decide on model enhancements
N-Aquifer Impact Criteria v Drawdown ü ü ü Sustained flow rates Compaction Increased pumping lifts Spring Flows v Ecosystems v Water Quality v ü ü v Current Movement Economic