Northern Arizona Hydrogeology

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1 Northern Arizona Hydrogeology Some basics Coconino Plateau Hydrogeology Flagstaff and Coconino Plateau Water Resources Well development, City of Flagstaff Effluent discharge to the Rio de Flag from Wildcat WTP Blue Spring, Little Colorado River

2 Competing water demands as a setup for conflict Nationally and Globally. Water rights surface water vs groundwater water quality T&E species ecosystem needs export/virtual water use

Aquifer System Components Three basic components Recharge Discharge Storage Recharge components Direct from precipitation From surface water

3 Aquifer System Components Three basic components Recharge Discharge Storage Recharge components Direct from precipitation From surface water Storage Underflow Discharge components Storage Springs and streams (baseflow) ET Underflow Steady-State Condition where Recharge = Discharge

4 Conservation of energy and mass. I.E. no free lunch Safe yield does not exist. At best it is a legal term that describes planned depletion. Dynamic Equilibrium and Water Balance storage Steady State Transient Sustainable yield meets both human and environmental water demands

5 What happens when groundwater is pumped? Depends on: Pumping rate Hydraulic conductivity (transmissivity) of the aquifer Extent of the aquifer Low Hydraulic Conductivity High Hydraulic Conductivity

7 Initial development Stream or spring capture Stream or spring disconnected from ground water Distance in feet or miles effects timing

8 Basic Principles 1. Any sustained pumping less than the basin recharge will eventually be balanced by an increased inflow and (or) decreased outflow. 2. In the basins of the Southwest, almost all of the capture will be in the form of decreased outflow. 3. A groundwater development that stops after a period of time will have the effect of reducing the cumulative volume of outflow (assuming no increased inflow) by the total quantity pumped over the period of active pumping. Inflow: Q 0 Pumping: Outflow: Q 0 Time

9 Basic Principles 1. Any sustained pumping less than the basin recharge will eventually be balanced by an increased inflow and (or) decreased outflow. 2. In the basins of the Southwest, almost all of the capture will be in the form of decreased outflow. 3. A ground-water development that stops after a period of time will have the effect of reducing the cumulative volume of outflow (assuming no increased inflow) by the total quantity pumped over the period of active pumping. 4. Pumping in a bedrock aquifer can capture recharge from an adjacent basin. Basin 1 Basin 2 Q

10 Water, Northern Arizona Lake Mead Lake Powell Flagstaff Prescott Verde Valley Holbrook Arizona arid and semi-arid hydrology Low precipitation High evaporation and transpiration (plants) Few perennial streams Water is primarily stored in the subsurface Lake Roosevelt

11 Where does the water come from and where does it go?

12 But it s the same every year right?

13 Precipitation (A) and Temperature (B) change, 1950 to 2013 Flagstaff, Arizona (Hereford, 2014).

14 40 35 Dry period ( ) Annual Precipitation and Annual Average Precipitation, Flagstaff Pulliam Airport Dry period ( ) Dry period (1996/97- present) Precipation, inches average, 22.6 in average, 20.6 in Year ~120 % normal November 3, 2015

15 Surface Water, Northern Arizona Lake Mead Lake Powell Havasu Spring Blue Springs Flagstaff Prescott Mormon Pocket Sterling Spring Page Springs Montezuma s Well Fossil Springs Artesian Spring Hugo Meadow Holbrook Perennial stream Intermittent or ephemeral stream Largest Reservoirs in the Continental U.S. One of the largest river systems in the Continental U.S. Few other perennial streams Lake Roosevelt

16 Ground Water, Northern Arizona Lake Mead Lake Powell Prescott Havasu Spring Mormon Pocket Page Springs Montezuma s Well Fossil Springs Blue Springs Flagstaff Artesian Spring Black Mesa Basin Hugo Meadow Holbrook Several regional aquifers at different depths Many local perched water-bearing zones N aquifer C aquifer R-M aquifer Few large springs represent major discharge zones for regional aquifers Ground-water supports base flow of few perennial streams Lake Roosevelt

Potentiometric surface (water level), in feet above sea

17 Greater than 2,000 mg/l TDS Greater than 500 mg/l TDS Holbrook Approximate extent of salt deposits Potentiometric surface (water level), in feet above sea level Na-Cl water (Supai origin?) Ca-Mg-HCO3 water (Kaibab origin?) Show Low

18 Black Mesa Basin and Arizona Strip Aquifers and Water-Bearing Zones C aquifer

19 Where does the water go? Evapotranspiration Runoff Ground-water recharge Perched water-bearing zones C aquifer Redwall-Muav aquifer

20 SPRINGS SPRINGS Conceptual model Flow system: Southern Colorado Plateau, NAZ San Francisco Peaks N ET RECHARGE Mesa Butte Fault RECHARGE ET ET RECHARGE ET RUNOFF ET ET S Grand Canyon Lowpermeability rocks Verde Valley

21 Improved geologic and structural information leads to a better understanding of the hydrogeologic framework North South West East

22 C aquifer occurrence and movement

23 Redwall-Muav aquifer occurrence and movement

24 How much water is there? Conceptual Model, water budget components Dynamic equilibrium 302,000 acre-feet 8,000 acre-feet 6,000 acre-feet From USGS SIR , Hydrogeology of the Coconino Plateau

25 Flow systems no longer in equilibrium: withdrawals, drought, changing land use, etc. From USGS SIR , Hydrogeology of the Coconino Plateau = 8,000 acre-feet -313,000 acre-feet 6,000 acre-feet

26 76 Figure 6b , Havasu Creek above the mouth near Supai, Arizona Dry period (1996/97-present) 27-year mean figure 6e , Verde River near Paulden, Arizona 50-year mean Dry period (1996/97- present) Winter base flow, ft 3 s % decline Winter base flow, ft 3 /s % decline (different flow system) Year Year Figure 6f , Verde River near Clarkdale, Arizona Figure 6c , Oak Creek at Sedona, Arizona Figure 6d , Wet Beaver Creek near Rimrock, Arizona Winter base flow, ft 3 /s year mean Dry period (1996/97- present) Winter base flow, ft 3 /s year mean Dry period (1996/97- present) Winter base flow, ft 3 /s year mean Dry period (1996/97 -present) % decline Year % decline Year % decline Year

27 City of Flagstaff Water Supplies (notice most wells on forest service lands) Local Springs Inner Basin Wells Lake Mary Local Springs Woody Mountain Well Field Lake Mary Well Field Red Gap Ranch Inner City Wells Red Gap Ranch? From City of Flagstaff Report to the Water commission, 2012

28 Development of water resources on Forest Service lands Administering National Forest System lands to secure favorable conditions of water flow (Organic Administration Act of 1897) SPECIAL USE PERMIT specify that the well be located, constructed, and operated in a manner that would avoid or minimize impacts to the groundwater-dependent ecosystem. 35 gallons per minute or greater would be required to monitor and report groundwater withdrawals PROPOSED GROUNDWATER DIRECTIVE FSM 25 (May, 2014) Encourage source water protection and water conservation. Require the evaluation of potential impacts from groundwater withdrawals on NFS natural resources.

29 Observatory Mesa Note buildings at the base of Observatory Mesa. Site of Old Town, Antelope/Old Town Spring San Francisco spring (MNA) Leroux springs O Neill spring Cline Library Special Collections

30 Inner Basin Springs and wells Credit: Jon Mason

in 1898 to the south of Flagstaff Cline Library

31 1890s construction of pipeline from Inner Basin to Flagstaff Normal School to train teachers completed in 1898 to the south of Flagstaff Cline Library Special Collections Lower LM Dam 1905 AZ Lumber and timber Co

Upper Lake Mary built by the city in 1941.

32 Upper Lake Mary built by the city in Crest raised 10 ft. in Credit: Don Bills Capacity of Lake Mary when full 16,300 ac-ft. About a 2-year supply at 2010 water use rates

33 Lake Mary Contents, 1949 to Dry period ( ) Dry period ( ) Dry period (1996/97- present) Lake Contents, acre-feet Lake Mary Contents at spillway crest, 16,300 acre-feet Year 63 year average capacity, 7,100 acre-feet (45%) From City of Flagstaff Report to the Water commission, 2015

34 Observation Wells Lake Mary 1 City of Flagstaff, Continental #2, (A-21-08) 17BCA2 Water level, in feet below land surface ft decline /1/19501/1/19551/1/19601/1/19651/1/19701/1/19751/1/19801/1/19851/1/19901/1/19951/1/20001/1/20051/1/2010 Year Woody Mountain 5 Water Level (feet below land surface) Time (year) NPS-Wupatki, Citadel Well (A-25-09) 06CCD Water level, feet below land surface /1/1960 1/1/1965 1/1/1970 1/1/1975 1/1/1980 1/1/1985 1/1/1990 1/1/1995 1/1/2000 1/1/2005 1/1/2010 Year Water Level (feet below land surface) ~50 ft decline ~2 ft decline Time (year)

35 Seismic studies, djbills, USGS 1996, the City, working with USGS, began to explore for sites and develop wells in the Inner City area. By 2012, 7 wells in operation. I-40 well, djbills, USGS

36 Mountain 12% Stream Source: Report to Water Commission, 2013, p. 17 ( average) Conservation and reuse (goal 20% actual, 30%) 40% Deep Rock 48%

37 Red Gap Ranch: Part of the City s water future?

Northern Arizona Regional Ground-Water Flow Model Background Product of the USGS and ADWR Rural Watershed Initiative studies in Northern Arizona.

resources throughout the region. Objective Improve understanding of hydrologic processes on a regional scale.

38 Northern Arizona Regional Ground-Water Flow Model Background Product of the USGS and ADWR Rural Watershed Initiative studies in Northern Arizona. Addresses the need for a tool that can be used to evaluate regional water supply and demand scenarios on the sustainability of water and environmental resources throughout the region. Objective Improve understanding of hydrologic processes on a regional scale. Provide boundary conditions for local, nested models. Provide a numerical tool to identify data collection needs. Provide a numerical information tool for management and protection of water resources.

39 Model area is over 26,000 mi 2, one of the largest attempted in the country to date (Ogallala and Central Valley in Calif. are bigger)

discretionization of model domain into cells and layers. 3.

40 How does a numerical model work? Darcy s Law By Bennett and Giusti 1. Determine physical characteristics of model domain. 2. discretionization of model domain into cells and layers. 3. Application of physical characteristics to cells and layers. 4. Model calibration and sensitivity analysis.

41 Characterization of model layers based on geology

42 Translate conceptual models to numerical models: Hydrology N AZ Regional Ground-Water Flow Model Water-Level Contours for Steady State Conditions Steady-State Ground- Water Altitude Contours - ~300 ft Flagstaff Holbrook Ground-water divide St. Johns Pre-development, 1910 in this model

43 Water Withdrawals (Average annual pumping rate per decade)

44 No data or missing control Williams Flagstaff Big Chino Holbrook Little Chino Sedona Prescott Verde River Snowflake St. Johns Payson

45 Potential future water demand No data or missing control Williams Flagstaff Big Chino Holbrook Little Chino Sedona Prescott Verde River Snowflake St. Johns Future demand 1,000 ac-ft or greater Payson

C and R-M aquifer BY 2050, THE COCONINO PLATEAU S WATER DEMANDS WILL SIGNIFICANTLY EXCEED SUPPLY * C aquifer Non-Tribal demand increases by 14,483 acre-feet by 2050 City of Flagstaff recently

46 C and R-M aquifer BY 2050, THE COCONINO PLATEAU S WATER DEMANDS WILL SIGNIFICANTLY EXCEED SUPPLY * C aquifer Non-Tribal demand increases by 14,483 acre-feet by 2050 City of Flagstaff recently increased its demand estimate from 16,808 at 2050 to 20,000 at 2100 Tribal demand increases by over 100 gallons per capita per day by 2050 (Charts from the North Central Arizona Water Supply Appraisal Study)

47 Use of Regional flow model to test water development scenarios on the Coconino Plateau (Draft-provisional) Black dots are simulated wells added to the model in areas where groundwater withdrawals are expected to increase or develop

48 No data, missing control and/or aquifer misrepresented Different models, different results Groundwater models are great tools for qualitative and quantitative assessment of aquifers. But

49 Importance of Monitoring in Quantitative Assessments of Stream Flow and Groundwater Flow Long-term monitoring Base flow Spring discharge water levels Withdrawal rates

50 Green dots and triangles only actively monitored sites Is it enough?

51 Comments, questions, contact info Donald Bills (928)

MEMORANDUM. FROM: Jordan Kear, P.G., C.Hg. KG

MEMORANDUM. FROM: Jordan Kear, P.G., C.Hg. KG MEMORANDUM TO: Mr. Robert Elliott Little Baldy Water Company PO Box 313 Llano, California 93544 FROM: Jordan Kear, P.G., C.Hg. KG12-0100 DATE: July 20, 2012 SUBJECT: Reconnaissance Level Hydrogeologic