# Attachment 1:

Tolk/Plant X Well Field Map!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.!.987657473636058626159X8X9X2X3X178767544434241403938373635343332313029282726252423222120191817161514131211105756555453525150494847464577X14X17X15X10X13X16Source: Esri, DigitalGlobe, GeoEye, i-cubed, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN,IGP, swisstopo, and the GISUser Community, Esri, HERE, DeLorme, TomTom, MapmyIndia,© OpenStreetMap contributors, and the GIS user communityLegendPipelineSPS water rights!.Wells ́

# Attachment 2:

Tolk/Plant X Annual Well Production TableYearwellcountwellsw/data%wellstestedPeakflowrate(gpm) newwellsnewwellpeakflowrate(gpm)%ofprodfromnewwellsprodchange(gpm)prodchangeofextwells(adjtoremnewwells)(gpm)AnnualWaterProduction(AF) Notes1992 46 31 67% 0 0 0% 0 DatadonotincludeXwells1995 46 25 54% 0 0 0%‐4,672 0 DatadonotincludeXwells2004 54 48 89% 15,800 8 2,730 17% 0 18,026 Xwellsincluded2005 54 47 87% 15,282 0 0 0%‐518‐518 17,162 Xwellsincluded2006 5415,2092007 55 40 73% 11,551 1 445 4%‐3,731‐4,176 14,529 Xwellsincluded2008 60 43 72% 12,588 5 2,643 21% 1,037‐1,606 14,496 Xwellsincluded2009 61 42 69% 12,889 1 550 4% 301‐249 12,798 Xwellsincluded2010 61 49 80% 13,858 0 0 0% 969 969 14,063 Xwellsincluded2011 65 49 75% 12,903 4 881 7%‐955‐1,836 13,399 Xwellsincluded2012 69 52 75% 13,040 4 478 4% 137‐341 14,813 Xwellsincluded2013 73 59 81% 12,858 4 1,582 12%‐182‐1,764 15,710 Xwellsincluded2014 73 47 64% 11,281 0 0 0%‐1,577‐1,577 9,486 Xwellsincluded40506070809010002,0004,0006,0008,00010,00012,00014,00016,00018,0002004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 No. of wells

Peak flow rate (g,pm)Wellfieldproductivityvs.numberofwellswellcountPeakflowrate(gpm)

# Attachment 3:

LBG-Guyton Associates Tolk	Station/Plant	X	Water	Right s	Area	Saturated	Thickness	and

Static	Volume

# LBG-GUYTON ASSOCIATES

PROFESSIONAL GROUNDWATER AND

ENVIRONMENTAL ENGINEERING

1101 CAPITAL OF TEXAS HIGHWAY

SUITE B-220

AUSTIN, TX 78746

512-327-9640

FAX: 512-327-5573



# June 17, 2015

Ms. Amy Willhite

Water Resources Analyst

Xcel Energy

10800 Larimer Street, Suite 1300

Denver, CO 80202-1414

Re: Tolk Station/Plant X water rights area saturated thickness and static volume

Dear Ms. Willhite,

We have completed the calculation of saturated thickness and static volume for the

groundwater contained within the Ogalalla Aquifer beneath the Xcel water rights area in

Lamb County, Texas.

These data were based primarily on measurements collected on April 14-15, 2015, which

are presented in the enclosed table with comparisons to measurements performed in May

2014. The measurements were collected during a shutdown period for Tolk Station, and

should represent static aquifer levels at each location. Some

Additional data provided by the High Plains Underground Water Conservation District

from 2015 were used to supplement the sparse measurements in the western portion of

the water rights area.

The measurements were used to prepare estimated saturated thickness contours, which

are provided in the enclosed map. As you are aware, the area of highest saturated

thickness is in the eastern portion of the water rights area, with a saturated thickness over

100 feet in the areas immediately adjacent to and east of Hwy 385. This thickness

gradually decreases to 40 feet west of Plant X.

Static volume contained within the water rights was estimated based on this saturated

thickness. We used the same assumptions as in our previous static volume calculations for

## Ms. Amy Willhite

June 17, 2015

Page 2



# the Xcel properties in Lamb County: a recoverable volume boundary of 40 feet above the

base of the aquifer, and a specific yield of 15%.

The estimated static volume in storage for the entire property (in terms of acre-feet) is

presented in the table below:

Section Area

(ac) Recoverable

Volume

(>40ft @ 15%

Yld) (ac-ft) Volume Change

From May 2014

Estimate (ac-ft)

Area for potential

future development 8,011 39,000 +21,000

Area of currently

un-economic

groundwater 4,413 4,000 +2,000

Area for potential

future exploration 5,777 14,000 -17,000

Current Use Water

Rights Area 25,359 82,000 -17,000

Total Xcel Water

Rights Area 43,560 139,000 -11,000



# This represents the estimated static volume directly beneath the Xcel properties, and may

be considered the lower bound of how much water can be economically recovered from

those properties with vertical water wells.

The volume contained within the shaded areas on the enclosed map represents

groundwater that will not quickly flow to existing wells in the current-use water rights

area. The blue shaded area has the advantage of being close to the plant, although there

are no existing wells in this area. The yellow area may potentially be developed, although

an exploration program would be required to verify the production potential of this area.

The orange area represents an area with saturated thickness that is too low to be

economic with vertical wells, and would likely only be available for production with

alternative well completions.

The change in estimated recoverable volume from 2014 for the current-use water rights

area is a decrease of 17,000 acre-feet. All of the water level measurements were collected

in this area, therefore this estimate is supported by the most data.

The estimated recoverable volumes for the potential future development and potential

future exploration area changed signifcantly from last year's estimate. These estimates are

dependent on sparse data from wells surrounding the Xcel properties. Small increases and

decreases in water level measurements in these wells affect a large area, and have a

similarly large impact on volume estimates. This effect is magnified in percentage terms

## Ms. Amy Willhite

June 17, 2015

Page 3



# because only volumes above 40 feet of saturated thickness are included in the recoverable

volume estimate.

If you have any questions about this information, please call me at 512-327-9640.

Sincerely,

LBG-G UYTON 

# A SSOCIATES



# Tyler A. Davidson, P.E.

Associate

Enclosure

cc: Mr. Richard Belt, Xcel Energy

## Tolk Station/Plant X May 2015 Static Level Measurements

Well ID

5 230.4 (4.4)

7 236.3 (8.9)

10 223.7 2.6

11 217.1 (1.7)

14 214.5 (2.3)

17 205.9 (3.2)

18 229.8 (5.4)

23 219.9 not measured in 2014



## 25 186.8 (3.6)

28 201.0 5.5

37 198.6 (4.4)

40 198.1 (6.0)

43 206.8 not measured in 2014



## 44 207.5 0.6

45 209.8 0.4

47 215.4 (2.0)

53 204.3 (2.0)

54 195.0 (5.8)

61 227.0 (14.4)

X2 144.5 (1.8)

X16 180.2 not measured in 2014



## Depth to Water

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