The mountain is permeable and fractured: Hydrological Connectivity in the Laramie Range

WyCHEG Interest Group Meeting, Oct 30, 2017, Laramie, WY The mountain is permeable and fractured: Hydrological Connectivity in the Laramie Range Ye Zhang 1, Brad Carr 1, Shuangpo Ren 2, Andy Parsekian 1 1.Dept. of Geology & Geophysics, University of Wyoming 2. Dept. of Petroleum Engineering, China University of Geosciences

Mountain Hydrology Laramie Range Laramie Range https://commons.wikimedia.org/w/index.php?curid=11121878

Blair Wallis N wetland Granite outcrop Wyoming Blair Creek Blair Creek Well field Granite outcrop Medicine Bow National Forest Mapped lineaments Granite outcrop 0 1 2 km

Blair Wallis Fractured Rock Well Field Geology: fractured granite & metamorphic rock overlain by weathered granite; 2 miles South of Blair Wallis Well Field, WYDOT Hydrology: surface & subsurface hydrology dominated by snowmelt. Hydrological Research: SW & GW monitoring & GW well tests; Geophysical Research: borehole & surface (seismic, resistivity, GPR, NMR, gravity, etc.) Petrophysics research: extend from field to mountain scale; http://www.justtrails.com/tag/vedauwoo/

Blair Wallis Fractured Rock Hydrology Research Well Field N wetland Blair Creek 0 100 200 m Cross-hole hydraulic communication exists among BW 6, 7, 8, 9, and BW1.

Drilling at Blair Setting surface casing made of PVC at BW6

Cores from BW5 Natural Clay from BW6 killed our pump Sulfide-Rich Cores from BW4

BW-1 BW-2 BW-3 BW-4 BW-5 BW-6 BW-7 BW-8 BW-9 Coord. 41.183939 N, 105.394125 W 41.183888 N, 105.397732 W 41.185873 N, 105.399440 W 41.184046 N, 105.393329 W 41.184099 N, 105.398273 W 41.183842 N, 105.394332 W 41.183989 N, 105.394456 W 41.183904 N, 105.394667 W 41.183753 N, 105.394551 W TD (m) 30.27 16.03 39.10 58.61 39.02 60.76 72.83 76.2 60.96 Casing depth (m) 17 6.1 6.7 9.8 18 17.07 17.07 16.76 17.07 Casing diameter (inch) Borehole diameter *1 (inch) 7 steel casing 7 pvc casing 7 pvc casing 4 pvc casing 4 pvc casing 6 pvc casing 6 pvc casing 6 pvc casing 6 pvc casing 4 7/8 5.5 5.5 ~3.8 ~3.8 5 5 5 5 Rock type Sulfide-rich DTW (m) *2 11.8 (8/15/2015) 11.03 (11/18/2015) Drilling method air/water rotary +coring; air/water rotary +coring; not developed 5.7 (9/11/2015) wireline+coring (drilled with water); not developed 11.7 (11/18/2015) wireline+coring (drilled with water); 10.9 (9/11/2015) wireline+coring (drilled with water); 13.18 from toc (9/8/2016) 12.645 bgs (8/31/2016) air/water rotary + downhole hammer *3 11.835 from toc? (9/8/2016) 11.755 bgs (9/1/2016) air/water rotary + downhole hammer; 13.743 (12/8/2016) air/water rotary + downhole hammer; 12.947 (12/8/2016) air/water rotary + downhole hammer; *1 This is diameter of the open borehole beneath the casing (see the diagram on previous page; also see caliper logs); *2 From top of casing (TOC) unless it is labeled as bgs (below ground surface); continuous WL monitoring is available since May, 2015. *3 No corings for BW 6, 7, 8, and 9. Note most shallow saprolite wells (Brady s; Austin s) in Blair Wallis were drilled using the backpack shaw drill.

Well Field Summary 9 bedrock wells completed in the saturated fractured granite; A subset of 5 wells (BW1, 6, 7, 8, 9) are hydraulically connected; 4 or 5 shallow wells completed in saturated weathered granite; 7 NMR boreholes completed in unsaturated weathered granite; All wells & boreholes: monitoring water pressure & temperature; Hydraulic tests: single well & cross-hole interference tests (hydraulic tomography);

Well Field Observations Numerous bedrock fractures observed in cores and wireline logs; Short-term pumping tests (up to 44 hr) show from very-low to moderate productivity; BW4 Bedrock equivalent K H : 10-7 ~10-4 m/s (fine to medium sand); Fresh water (TDS<100 mg/l); a few tests produced suspended sediments (granite minerals & clay); 28 hr pumping test @ 20 gpm; Drawdown in BW4 is ~12 m; BW1, 40 m away, had no response;

BW 7 Test Variable fracture connectivity: differential drawdowns in monitoring wells; Sediment production causes pumping rate to reduce; Drawdown stabilization at 3.5 gpm: water-supply BC (stream loss); DTW(m) 8/22/2017 0:00 8/22/2017 12:00 8/23/2017 0:00 8/23/2017 12:00 8/24/2017 0:00 8/24/2017 12:00 8/25/2017 0:00 10 12 14 16 18 20 22 24 26 28 manual measurement transducer Sediment production

Recharge & Discharge Recharge: GW level is dominated by annual spring snowmelt indicating connectivity to surface. Discharge: GW flow to basin is estimated at 6~19% of the total precipitation over the Laramie Range, assuming local-scale K data at Blair extends to mountain scale.

Denver Basin Casper Aquifer

Laramie Basin: Casper Aquifer Monitoring Recharge to Casper Aquifer from above during annual snowmelt. Taboga (2006)

Laramie Basin: Casper Recharge Study Head (~20 bgs) Artesian (~13 ags) Sept-Oct, 2017: Hydraulic gradient exists for upward flow, supplying a sub-charge to Casper Aquifer Granite flow at ~2 gpm

Broader Connectivity Exists between snow, streams, lakes/reservoirs, soil, & groundwater regimes; Degrees of connectivity varies; Complex interaction.

Scientific: Implications Advance understanding of mountain hydrology & snowmelt partitioning into SW and GW; Management: Opportunities (mountain block v. mountain front recharge); Vulnerability; Conjunctive SW/GW management; Future Work: Petrophysics linking aquifer properties to geophysics for mountain scale surveys;

Extra

Casper Aquifer Monitoring Program & UW Golf Course Laramie Range Red Buttes Gov Gulch Site Laramie Basin Blair Wallis Fractured Rock research well field 6 stream sites with 12 riparian wells Monitored reservoirs Belvoir Ranch High plains aquifer monitoring well network (ALTAS site) Denver Basin

Acknowledgement Students: Shuangpo Ren, Sam Grag, Sam Coker; Consultants: Chris Moody, Bern Hinkeley, Mark Stacy; Funding: NSF, Wyoming Water Research Program, USGS; Cooperating Agencies: USFS, State of Wyoming DEQ, Cheyenne BOPU;

BW4

Denver Basins: Belvoir Ranch Stream, Riparian, and Casper Aquifer Study Upper Lone Tree Creek watershed Upper Goose Creek watershed A C B BELVOIR RANCH Upper Duck Creek watershed Upstream flow stations Downstream flow stations Existing monitoring wells Casper formation outcrop

Belvoir Ranch: SW/GW Connectivity Precipitation and Snow Water Equivalence (mm) Water depth in stream (m) 140 120 100 80 60 40 20 0 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 SWE (mm) Precipitation (mm) 5/16 5/19 5/21 5/24 5/27 5/29 6/1 6/4 6/6 6/9 6/12 6/14 6/17 6/20 6/22 6/26 6/29 7/1 7/4 7/7 7/9 7/12 7/15 7/17 7/20 7/23 7/25 7/28 7/31 8/2 Stream WL, upstream site Stream WL, downstream site Ground water depth at LTC Mon #1 5/16 5/19 5/21 5/24 5/27 5/29 6/1 6/4 6/6 6/9 6/12 6/14 6/17 6/20 6/22 6/26 6/29 7/1 7/4 7/7 7/9 7/12 7/15 7/17 7/20 7/23 7/25 7/28 7/31 8/2 70 68 66 64 62 60 58 56 54 52 Ground water depth (m)

Laramie Basin: Casper Recharge Study Sept-Oct, 2017: Hydraulic gradient exists for upward flow, thus a sub-charge to Casper Granite interval: image & flowmeter logs outflow Head (~20 bgs) Artesian (~13 ags) Granite flow at ~2 gpm bgs (m) inflow

Geology of southern Wyoming UW GG