Embed Size (px)
Citation preview
Groundwater Availability Modeling (GAM) for the
Dockum Aquifer
Stakeholders Advisory Forum 3Model Calibration Results
June 4, 2008
Outline
Aquifer ReviewModel DesignConceptual ModelModel ImplementationModel CalibrationModel ResultsModel ConclusionsModel LimitationsGAM Schedule
Aquifer ReviewAquifer Review
Aquifer Location F
ile: 2
_01_
stud
y_ar
ea.m
xd
Source: N/A
Dockum Aquifer Study Area
0 50 100
Miles
−State Line
Study_Area
Model Boundary
Downdip Aquifer Limit
County Boundaries
Study Area Model Domain
Lea
Eddy
Chaves
Pecos
Union
Quay
Colfax
Reeves
Culberson
Ellis
DeBaca
Harding
Curry
Texas
San Miguel
Roosevelt
Irion
Mora
Crockett
Hall
Hale
Dallam
Gaines
Jeff Davis
Upton
Hartley
King
Kent
Oldham Gray
Lynn
Beaver
Caddo
Guadalupe
FloydLamb
Terry
Coke
Andrews
Ector
Major
Knox
Kiowa
Mills
Clay
Nolan
Ward
Jones
Potter
Cottle
Taylor
Brown
Custer
Motley
Reagan
Blaine
Young
Dewey
Garza
Martin
Fisher
Coleman
Llano
Baylor
Moore
Archer
Scurry
Tom Green
Castro
Cimarron
Bailey
Deaf SmithDonley
Crane
Runnels
Carson
Concho
Crosby
Schleicher
Washita
Borden
Haskell
Tillman
Erath
Randall
Sterling
Woods
Foard
BriscoeParmer
MitchellHoward
Menard
Roberts
Woodward
Mason
San Saba
Midland
DickensHockley
Swisher
Winkler
Greer
Dawson
Wheeler
Harper
Jack
Eastland
Lubbock
Hemphill
Alfalfa
McCulloch
Roger Mills
Ochiltree
Loving
Wilbarger
HansfordSherman
Callahan
Yoakum
Jackson
Cotton
Comanche
Beckham
Lipscomb
Stephens
Stonewall
Cochran
Armstrong
Glasscock
Comanche
Wichita
Hutchinson
Shackelford Palo Pinto
Childress
Sutton
Harmon
Hardeman
Kimble
Collingsworth
Throckmorton
Burnet
Lampasas
Terrell
coln
Hamilto
Canadia
Kingfis
BrewsterPresidio
ero
Gra
Garf
Steph
File
: 2_0
2_do
ckum
_aqu
ifer.m
xd
Source: Online: Texas Water Development Board, Aug 2006
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
Dockum AquiferOutcrop
Downdip
−0 25 50
Miles
Aquifer Location
File
: 2_0
7_R
WP
.mxd
Source: Online: Texas Water Development Board, June 2006
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
RWPs
Panhandle
Llano Estacado
Brazos G
Region F
−0 25 50
Miles
File
: 2_0
8_G
CD
s.m
xd
Source: Online: Texas Water Development Board, June 2006.
North Plains GCD
PanhandleGCD
High PlainsUWCD No. 1
SandyLand
UWCD
South PlainsUWCD
Llano Estacado
UWCDMesa
UWCD
Permian BasinUWCD
Garza CountyUWCD
Salt Fork
UWCD
Lone WolfGCD
ClearForkGCD
Wes-TexGCD
GlasscockGCD
Sterling County UWCD
Coke CountyUWCD
IrionCountyWCD
SantaRita
UWCD
EmeraldUWCD
Middle PecosGCD
−0 25 50
Miles
State Line
Model Boundary
County Boundaries
Downdip Aquifer Limit
GCDs, UWCDs, WCDs
Groundwater Conservation Districts Regional Water Planning Groups
River Basins and Topography
Major River Basins Topography
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
River Basins
Canadian River Basin
Red River Basin
Brazos River Basin
Colorado River Basin
File
: 2_1
0_riv
er_b
asin
s.m
xd
Source: Online: Texas Water Development Board, June 2006; New Mexico Resource GIS Program, June 2006
Rio Grande River Basin0 25 50
Miles
−
File
: 2_1
3_to
po.m
xd
Source: Online: USGS, Aug 2006
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
Land Surface Elevation(ft-MSL)1,406 - 1,5001,501 - 2,0002,001 - 2,5002,501 - 3,0003,001 - 3,5003,501 - 4,0004,001 - 4,5004,501 - 5,0005,001 - 5,5005,501 - 6,0006,001 - 6,5006,501 - 7,0007,001 - 7,5007,501 - 8,0008,001 - 8,5008,501 - 9,000
0 25 50
Miles
−
Model DesignModel Design
Modeling Protocol
Compile and Analyze Field and Literature DataDevelop a Conceptual ModelModel DesignCalibrate the ModelUse the Model for Predictive Purposes
Schematic of Modeling PeriodsPre-development
(Steady-State) Post-development Calibration(Transient)
1950 1980 1997
Observed Water LevelModel Water Level
Conceptual ModelConceptual Model
Conceptualization of Groundwater Flow
Undifferentiated Permian
Upper Dockum
Lower Dockum
Ogallala
Cretaceous
Upper Dockum
Lower Dockum
General Head BoundaryRecharge (Precipitation)Discharge (ET, Springs)Discharge vie PumpingSurface Water-Aquifer InteractionCross-Formational FlowNo-Flow Boundary
AquiferOutcrop
Aquifer Outcrop
NW SE
Ogallala/Younger
Aquifer Directly Overlying the Dockum
Lea
Eddy
Chaves
Pecos
Quay
Union
Colfax
Reeves
Culberson
Ellis
DeBaca
Harding
Curry
San Miguel
Crockett
Roosevelt
Mora
Irion
Hall
Texas
Jeff Davis
Hale
Dallam
Gaines
Upton
Hartley
King
Kent
Oldham Gray
Guadalupe
Lynn
Caddo
FloydLamb
Terry
Coke
Andrews
Ector
Beaver
Major
Knox
Kiowa
Mills
Llano
Nolan
Ward
Jones
Potter
Clay
Cottle
Taylor
Brown
Custer
Motley
Reagan
Blaine
Young
Dewey
Garza
Martin
Fisher
Coleman
Baylor
Moore
Archer
Scurry
Tom Green
Castro
Bailey
Deaf Smith Donley
Crane
Runnels
Carson
Concho
Crosby
Mason
Schleicher
Washita
Cimarron
Borden
Haskell
Tillman
Randall
Sterling
Foard
BriscoeParmer
MitchellHoward
Menard
Roberts
Woodward
San Saba
Erath
Midland
DickensHockley
Swisher
Winkler
Greer
Dawson
Wheeler
Woods
Eastland
Lubbock
Hemphill
McCulloch
Roger Mills
Ochiltree
Loving
Wilbarger
HansfordSherman
Callahan
JackYoakum
Jackson
Beckham
Lipscomb
Comanche
Stephens
HarperAlfalfa
Cotton
Stonewall
Cochran
Armstrong
Glasscock
Sutton
Wichita
Comanche
Hutchinson
Hardeman
KimbleTerrell
Shackelford
Childress
Collingsworth
Harmon
Throckmorton
Burnet
Lincoln
Hamilton
Canadian
Presidio Brewster
Otero
File
: Fig
.4.1
_Aqu
ifers
_Dire
ctly
_Ove
rlayi
ng_D
ocku
m
Source: Adapted from Texas Water Development Board, Dec 2006
−
State Line
Model Boundary
Aquifer Downdip Limit
Counties
Aquifer Name
Dockum Group Outcrop
Rita Blanca
Edwards-Trinity (High Plains)
Pecos Valley
Ogallala
Edwards-Trinity (Plateau) - Outcrop
Edwards-Trinity (Plateau) - Subcrop
0 25 50Miles
Dockum Thickness
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
! !
!
!
!
!!
!
!
!
!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
! ! !
!
!
!
!
!
! ! !
!
! !
! !
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
! !
! !
!
!!
!
!
!
!
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!!
!
!
!
!
!
!
!
! !!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
! !
!
!
!
!
!
!
!!
!!
!
!!
!
!
!
!!
!
!!
!
!
!
!
!
!
!!
!
!!
!
!
!
!
! !
!
!
!
!
!
!!
!
!
!
!
!
!
! !!
!!
!
!!
!!!
!
!
!
!
!!
!
!
!!
!
!! !
!
!
!
!!!
!!
!!
!
!
!
!
!
!!
!!
!
!!
!
!
!
!
!
!!
!
!!
!
! !
!
!!!
!!
!
!
!
!!
!
!
!!!
!!
!
!
!
!
!!
!
!
!
!
!
!!
!!
!
!
! !
!!
!
! !
! !
!
!
!!
!!
!
! !
!
!!
!
!
!
!
!
!
!!
!
!!
!!!
!!
!
!
! !
!!!
!
!
!
!!
!! !
! ! !
!!
!!
!
! !
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!!
!
!!
!
!
!
!!
!
!!
!
! !
!
!
!
!
!
!
!
!
!!
! !
!
!
!
!
!
!
!
!!
!
!
!
!!
!
!
!
! !
!!!!
!
!
!
!
!
!
! !
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!!
!!
!
!
!
!
!
!
!
!
!
!!
!
!
!!
!
!
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!
!!!
! !
!
! !!!
!
!!
! !
!
!
!
! !!
!!
!!
!
!
!!
!
!!!!
!!
!
!!
!
!
!
!
!
! ! !
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!
!
! !
!!
!!
!
!
!
!
!!
!!
!
!
!!
! !
!
!
!!!
!
!
!
!!
!
!!
!
!
!
!
!
!!
!!
! !
!
!
!
!
!
!
! ! ! !
! !
!!!
!
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!!
!!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
! !
!
!!
!
! !!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!!
!!
! !
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
! !
!
!
!
!
!!
! !
!
!
!
!
!!
! !
!
!!
!
!
!
!
!!!!
!
!
!
!
!
!! !
!
!
! !!
!!
!
! !
!
!
!
!
!
!
! !
!
!!
!
!
!
!
!
!
!
! !
!!
!
!!
!
! !
!
!
!!!!
!!
!
!
!
!
!
!
! !
!
!
!
!
!!
!
!
!
!
!
!!
!
!!
!
! !!
!
!
!
!
!
!
! ! !
!!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
!!!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!!
!
!
!!
!
! !
!
!
!
!
!
!!
!
!!
!
!
!!
!
!
!
!
!
!!
!!
!
!
!
!
!
!!
!! !
!
!
!
!
!
!!
!
! !
!!
!!
!
!
!
! !
!
!!
!!!
!
!!
! !! !!!
!
!!
! !
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
!!
!
!
!
!!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!! !
!
!
!
!
!
!!
!!
!
!
!
!
!
!!
!
!
!
!
!
! !
!
!
!
!
!!!
!!
!
!
!
!
!
!!
!
!
!
! ! !!!
!
!
!
! !
!!
!
!
! !
!
!
!
!
!!
!
! !
!
!!
!!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!! !
!
!
!!!
!!
!
!!
!
!!
!
!!
! !!
!
!
!
!
! !
!
!
!
!!
!
!
!
!
!
!
!
! !
! !
!
!!
!
!
!
!
!
!
!
!!
! !
!!
!
!
!
!
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!!
!
!
! ! ! !
!!
!!
!!
!
! !
!!
!!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
! ! !
!
!
!
!
!
!!
!
!
!
!
! !!
!!!
!
!! !
! !
!
!!
!!
!
!!
!
!
!!
!
!
!
!
!
!!
!
!
!
! !
! ! !
!
!!
!
!
!
!
!
!
! ! !!
!!!!
!
!
!
!! !
!
!
!
!
!!
!
!
!!
!
!
!! !
!
!
!
!
!
!
!
!
!
!!
!
!
!!!
!!!
!
!! !
!
!
!!
!!
!
!
!
!
!
!!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!!
!!
!!
!!
!
!
!
!!
!
!
!
!!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!!
!
!!
!
!
!
!
!!!!
!
!
!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!!
!
! !
!
!!
!
!
!!
!!
!
!
!
!
!!!
!
!
!!
! !!
! !
! !
!
!!
!!
!
!
!!!
!
!
!
!
!
!
!
!
!
!
! !!
!
!
!!
!
!
!
!!
!
!
!
!
!!
!!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
!
!
!
!
!
!
!
!
300
400
200
500
600
700
800
100
9001000
400
1000
100
600
700
500
300
900
100
600
800
700900
800
500
500
300
400
100
800
100500
900
100
100
300
100
100
700
100
400
200
200
400
200
100
200
500
800
File
: 4.2
.5_l
ower
_thi
ckne
ss.m
xd
Source: McGowen et al. (1977)
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
! McGowen Control Points
−0 25 50
Miles
Upper DockumThickness
(feet)20 - 100101 - 200201 - 300301 - 400401 - 500501 - 600601 - 700701 - 800801 - 900901 - 1,0001,001 - 1,1001,101 - 1,200
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
! !
!
!
!
!!
!
!
!
!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
! ! !
!
!
!
!
!
! ! !
!
! !
! !
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
! !
! !
!
!!
!
!
!
!
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!!
!
!
!
!
!
!
!
! !!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!!
! !
!
!
!
!
!
!
!!
!!
!
!!
!
!
!
!!
!
!!
!
!
!
!
!
!
!!
!
!!
!
!
!
!
! !
!
!
!
!
!
!!!
!
!
!
!
!
! !!
!!
!
!!
!!!
!
!
!
!!
!
!
!
!!
!
!! !
!
!
!
!!!
!!
!!
!
!
!
!
!
!!
!!
!
!!
!
!
!
!
!
!!
!
!!
!
! !
!
!!!
!!
!
!
!
!!
!
!
!!!
!!
!
!
!
!
!!!
!
!
!
!
!!
!!
!
!
! !
!!
!
! !
! !
!
!
!!
!!
!
! !
!
!!
!
!
!
!
!
!
!!
!
!!
!!!
!!
!
!
! !
!!!
!
!
!
!!
!
! !
! ! !
!
!
!!
!
! !
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!!
!
!!
!
!
!
!!
!
!!
!
! !
!
!
!
!
!
!
!
!
!!
! !
!
!
!
!
!
!
!
!!
!
!
!
!!
!
!
!
! !
!!!!
!
!
!
!
!
!
! !
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!!
!!
!!
!
!!
!
!
!
!
!
!
!!
!
!
!!
!
!
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!
!!!
! !
!
! !
!!
!
!!
! !
!
!
!
! !!
!!
!!
!
!
!!
!
!!!!
!!
!
!!
!
!
!
!
!
! ! !
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!
!
! !
!
!
!!
!
!
!
!
!!
!!
!
!
!!
! !
!
!
!!!
!
!
!
!!
!
!!
!
!
!
!
!
!!
!!
! !
!
!
!
!
!
!
! ! ! !
! !
!!!
!
!
!!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
! !
!
!!
!
! !!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!!
!!
! !!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
! !!
!
!
!
!!
! !
!
!
!
!
!!
! !
!
!!
!
!
!
!
!!!!
!
!
!
!
!!
! !
!
!
! !!
!!
!
! !
!
!
!
!
!
!
! !
!
!!
!
!
!
!
!
!
!
! !
!!
!
!!
!
! !
!
!
!!!!
!!
!
!
!
!
!
!
! !
!
!
!
!
!!
!
!
!
!
!
!!
!
!!
!
! !!
!
!
!
!
!
!
! ! !
!!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
!!!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!!
!
!
!!
!
! !
!
!
!
!
!
!!
!
!!
!
!
!!
!
!
!
!
!
!!
!!
!
!
!
!
!
!!
!! !
!
!
!
!
!
!!
!
! !
!!
!!
!
!
!
! !
!
!!
!!!
!
!!
! !! !!!
!
!!
! !
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !
!!
!
!
!!
!
!
!
!!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!! !
!
!
!
!
!
!!
!!
!
!!
!
!
!!
!
!
!
!
!
! !
!
!
!
!
!!
!
!!
!
!
!
!
!
!!
!
!
!! ! !
!!
!
!
!
! !
!!
!
!
! !
!
!
!
!
!!
!
! !
!
!!
!!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!! !
!
!
!!!
!!
!
!!
!
!!
!
!!
! !!!
!
!
!
! !
!
!
!
!!
!
!
!
!
!
!
!
! !
! !
!
!!
!
!
!
!
!
!
!
!!
! !
!!
!
!
!
!
!
!
!
!
!
!!!
!
!
!
!
!
!
!
!!
!
!
! ! ! !
!!
!!
!!
!
! !
!!
!!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
! ! !
!
!
!
!
!
!!
!
!
!
!
! !!
!!!
!
!! !
! !
!
!!
!!
!
!!
!
!
!!
!
!
!
!
!
!!
!
!
!
! !
! ! !
!
!!
!
!
!
!
!
!
! ! !!
!!!!
!
!
!
!! !
!
!
!
!
!!
!
!
!!
!
!
!! !
!
!
!
!
!
!
!
!
!
!!
!
!
!!!
!!!
!
!! !
!
!
!!
!!
!
!
!
!
!
!!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!!
!!
!!
!!
!
!
!
!!
!
!
!
!!
!
!!
!
!!
!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!
!
!
!
!
!
!!
!
!!
!
!
!
!
!!!!
!
!
!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!!
!
! !
!
!!
!
!
!!
!!
!
!
!
!
!!!
!
!
!!
! !!
! !
! !
!
!!
!!
!
!
!!!
!
!
!
!
!
!
!
!
!
!
! !!
!
!
!!
!
!
!
!!
!
!
!
!
!!
!!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!!
!
!
!
!
!
!
!
!
!
!
!
500600
700
400
800
900
1000
300
1100
200
1200
100
1300
700400
400
100
1200
300
700
1000
500
500
1000
300
300
900
200
400
400
900 800
1000
1000
400
800
600
300
800
200
300
200
1000
400
900500
100
800
400
200
1200
1000
200
1000
200
100
300
500
1000
100
1000
1200
700
100
1100
700
1000
800
900
200
300
900
1000
100
1000
800
500
900
100
600
100
100
800
300
400
300
700
900
1200
700
300
600
700
600
1000
800
File
: 4.2
.3_l
ower
_thi
ckne
ss.m
xd
Source: McGowen et al. (1977)
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
! McGowen Control Points
−0 25 50
Miles
Lower DockumThickness
(feet)50 - 100101 - 200201 - 300301 - 400401 - 500501 - 600601 - 700701 - 800801 - 900901 - 1,0001,001 - 1,1001,101 - 1,2001,201 - 1,3001,301 - 1,400
Upper Dockum Lower Dockum
Predevelopment Water-Level Elevations
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
Dockum Aquifer
Outcrop
Downdip
Water-Level Elevation (ft)
Measurement PointUpper Dockum Extent
Contour Interval = 100 ft
Miles
0 25 50
State Line
Model Boundary
Downdip Aquifer Limit
County Boundaries
Dockum Aquifer
Outcrop
Downdip
Water-Level Elevation (ft)
Measurement Point
Contour Interval = 100 ft
Miles
0 25 50
Upper Dockum Lower Dockum
Sand FractionUpper Dockum Lower Dockum
Horizontal Sand Hydraulic Conductivity
Miles
0 25 50
State Line
Downdip Aquifer Limit
County Boundaries
Model Boundary
Data Location
Horizontal HydraulicConductivity
(ft/day)
0
5
10
15
20
25
Miles
0 25 50
State Line
Downdip Aquifer Limit
County Boundaries
Model Boundary
Data Location
Horizontal HydraulicConductivity
(ft/day)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Upper Dockum Lower Dockum
Conceptual Model of Groundwater FlowOutcrop Areas– Recharge by precipitation and stream loss– Discharges to springs and streams and by ET
Subcrop with TDS < 5,000 mg/L– Portion of Dockum Group defined as an aquifer– Only lower Dockum present– Fresh water enters via cross-formational flow from overlying
Ogallala and Pecos Valley aquifers– Flow is towards the Canadian River in the northern portion of the
model area– Flow is towards the southeast along the eastern side of the
model area and discharge to springs or overlying formations– Flow is likely towards the trough in southwestern portion of
model area
Conceptual Model of Groundwater Flow
Subcrop with TDS > 5,000 mg/L– Correspond to the portion of the Dockum Group not defined as
an aquifer– Upper and lower Dockum present – Little movement of groundwater into or out of the deeper parts of
the depositional basin– No or insignificant displacement of connate water by meteoric
water– Connate water from recharge in eastern New Mexico prior to
Pleistocene time when Pecos River valley was eroded– Movement of water out of the deeper parts of the basin is
restricted by the high fluid density of the groundwater– Very little cross-formational flow from overlying aquifers due to
the high mudstone content in the upper Dockum
Model ImplementationModel Implementation
Model Grid
1 square mile grid blocks212 columns422 rows3 layers150,548 active cells
Stress Periods
period time type length1 pre-development ss2 1950-1959 tr 10 yrs3 1960-1969 tr 10 yrs4 1970-1974 tr 5 yrs5 1975 tr 1 yr. . . .. . . .. . . .
27 1997 tr 1 yr
Hydraulic Properties - Dockum
KH based on sand hydraulic conductivity and sand fraction:
Kv calculated as harmonic mean of sand and clay conductivities:
sandH KSFK ⋅=
claysand
V
KSF
KSFK
−+
= 11
Horizontal Hydraulic Conductivity – KH
Upper Dockum Lower Dockum
Vertical Hydraulic Conductivity – KV
Upper Dockum Lower Dockum
Storage Parameters
Specific Storage coefficient for upper and lower dockumaquifers are calculated using equation:Ss = SF*Ss-sand+(1-SF)*Ss-clay
where:SF– sand fractionSs-sand – sand specific storage : 3E-6 ft-1
Ss-clay – clay specific storage : 7.5E-6 ft-1
Ss-min – water specific storage : 1.3E-6 ft-1
Storativity product of specific storage and aquifer thicknessSpecific yield set to literature value in absence of data0.15
StorativityUpper Dockum Lower Dockum
Recharge Rate Estimates
County/Area Land use Aquifer Recharge (in/yr) Technique Reference Dockum Aquifer – Colorado River outcrop area All of the Colorado River outcrop area - Predevelopment Grassland and shrubland Dockum 0.08 SZ chloride mass
balance This report
Sandy areas (Nolan and eastern Mitchell counties) - Predevelopment Grassland and shrubland Dockum 0.22 SZ chloride mass
balance This report
All of the Colorado River outcrop area Dockum 0.08 to 0.2 UZ numerical
modeling Scanlon et al. (2003)
Western Scurry and Mitchell counties Grassland and shrubland Dockum <0.01 SZ chloride mass balance This report
Scurry County - Predevelopment Dockum 0.02 to 0.04 Water budget on playas This report
All of the Colorado River Outcrop area - Postdevelopment Dockum 2.2 regional water level
rise This report
Sandy areas (Nolan and eastern Mitchell counties) - Postdevelopment Cropland Dockum
Geom. Average = 1.7Median = 1.6
Range = 0 to 4.3
linear water level rises in individual wells
This report
County/Area Land use Aquifer Recharge (inch/yr) Technique ReferenceDockum Aquifer – Canadian River outcrop area All of the Canadian River outcrop area- Predevelopment and Postdevelopment
Grassland and shrubland Dockum 0.17 SZ chloride mass balance This report
All of the Canadian River outcrop area Dockum <0.08 UZ numerical
modeling Scanlon et al. (2003)
Dockum Aquifer – high TDS outcrop area Howard, Borden and Garza counties - Predevelopment Grassland and shrubland Dockum <0.01 SZ chloride mass
balance This report
Predevelopment Recharge
Recharge was estimated on limited points (80) using:
The correlation of estimated recharge to physical parameters was tested, however, no obvious correlation was foundA significance analysis (t-test) was conducted to determine whether average recharge rates should be divided into regions; no significant difference existedRecharge rates were weighted as a power function of the local topography and normalized to conserve total rechargePower coefficient adjusted until maximum recharge rate was reasonable (~0.5 in/yr)
GW
P
ClClPR =
Modern Recharge
Analysis of regional water-level rise was conducted– Colorado River outcrop rise indicates 2.2 in/yr effective recharge– Canadian River outcrop indicates no appreciable rise– includes recovery, stream loss, land-use impacts, return flow
For non-pumped, interstream wells with linear water table rise:– Recharge = ∆h/Sy∆t where median = 1.6 in/yr– Already have 0.15 in/yr historical recharge
Added 1.45 in/yr to cropland areas– Only added within Colorado River outcrop– Added to cells by percent cropland within cell
Recharge Distribution
ModernPredevelopment
General Head Boundary
Used to represent impact of the overlying aquifersPre-development heads based on observed dataTransient heads based on drawdown from Southern Ogallala GAM simulationsGHB Conductances large Dockum properties are primary limiter to flow
General Head Boundary1980Predevelopment
General Head Boundary19971990
Surface Water Boundary Conditions
Streams represented by STR package– Stream geometry (length, slope, width) from RF1 dataset– Streamflow from RF1 mean flow– Streambed conductance calibration parameter
Springs represented by DRN package– Drain elevations based on literature– Conductance calibration paramter
Evapotranspiration represented by DRN package– Attempt to use EVT package following Scanlon et al. 2005
resulted in convergence problems associated with EVT package– Drain elevation set to root extinction depth– Conductance large and flows compared with ETmax
Surface Water Boundary ConditionsUpper Dockum Lower Dockum
Pumping – 1950Upper Dockum Lower Dockum
Pumping – 1980 Upper Dockum Lower Dockum
Pumping – 1997Upper Dockum Lower Dockum
Model CalibrationModel Calibration
Upper Dockum Calibration – Predevelopment
Steady-State Upper Dockum Heads
2500
3000
3500
4000
4500
5000
2500 3000 3500 4000 4500 5000
Observed (ft)
Sim
ulat
ed (f
t)
RMSE 100.0 ftMAE 77.0 ftME 15.0 ftMin E -223.4 ftMax E 185.6 ft
Range 2403.6 ftRMSE/Range 4.16%MAE/Range 3.20%ME/Range 0.62%
Lower Dockum Calibration – Predevelopment
Steady-State Lower Dockum Heads
2000
2500
3000
3500
4000
4500
2000 2500 3000 3500 4000 4500
Observed (ft)
Sim
ulat
ed (f
t)
RMSE 65.1 ftMAE 48.4 ftME 15.1 ftMin E -136.7 ftMax E 273.8 ft
Range 2288.5 ftRMSE/Range 2.84%MAE/Range 2.12%ME/Range 0.66%
Predevelopment Head Residuals
Upper Dockum Lower Dockum
Upper Dockum Calibration – Transient
Transient Upper Dockum Heads
2500
3000
3500
4000
4500
5000
2500 3000 3500 4000 4500 5000
Observed (ft)
Sim
ulat
ed (f
t)
RMSE 80.3 ftMAE 60.3 ftME 46.8 ftMin E -60.3 ftMax E 164.0 ft
Range 2403.6 ftRMSE/Range 3.34%MAE/Range 2.51%ME/Range 1.95%
Lower Dockum Calibration – Transient
Transient Lower Dockum Heads
1500
2000
2500
3000
3500
4000
4500
1500 2000 2500 3000 3500 4000 4500
Observed (ft)
Sim
ulat
ed (f
t)
RMSE 94.3 ftMAE 65.6 ftME 0.1 ftMin E -243.6 ftMax E 316.2 ft
Range 2288.5 ftRMSE/Range 4.12%MAE/Range 2.87%ME/Range 0.01%
Transient Mean Residuals in Dockum
Upper Dockum Lower Dockum
Subcrop Randall 1015901
3512
3532
3552
3572
3592
3612
3632
3652
3672
3692
3712
1980 1985 1990 1995 2000Year
Head
(ft
Subcrop Randall 1016102
3608
3618
3628
3638
3648
3658
3668
3678
3688
3698
3708
1980 1985 1990 1995 2000Year
Head
(ft
Upper Dockum Hydrographs
Outcrop Deaf 908301
4007
4017
4027
4037
4047
4057
4067
4077
4087
4097
4107
1980 1985 1990 1995 2000Year
Hea
d (ft
Subcrop Deaf 1001601
4044
4054
4064
4074
4084
4094
4104
4114
4124
4134
4144
1980 1985 1990 1995 2000Year
Hea
d (ft
Outcrop Hartley 726101
3200
3220
3240
3260
3280
3300
3320
3340
3360
3380
3400
1980 1985 1990 1995 2000Year
Head
(ft
Subcrop Armstrong 1105101
3170
3180
3190
3200
3210
3220
3230
3240
3250
3260
3270
1980 1985 1990 1995 2000Year
Hea
d (ft
Lower Dockum Hydrographs
Outcrop Mitchell 2934805
2105
2115
2125
2135
2145
2155
2165
2175
2185
2195
2205
1980 1985 1990 1995 2000Year
Head
(ft
Outcrop Scurry 2925707
2128
2138
2148
2158
2168
2178
2188
2198
2208
2218
2228
1980 1985 1990 1995 2000Year
Hea
d (ft
Subcrop Motley 2201915
2546
2556
2566
2576
2586
2596
2606
2616
2626
2636
2646
1980 1985 1990 1995 2000Year
Head
(ft
Subcrop Winkler 4623701
2655
2665
2675
2685
2695
2705
2715
2725
2735
2745
2755
1980 1985 1990 1995 2000Year
Head
(ft
Sensitivity Analysis
-15
-10
-5
0
5
10
15
0.4 0.6 0.8 1 1.2 1.4 1.6
Fraction of Base Value
Mea
n He
ad D
iffer
ence
(ft) Kh-all
Kh-OgallalaKh-Upper-DockumKh-Lower-DockumKv-allKv-OgallalaKv-Upper-DockumKv-Lower-Dockum
Example: Effect of Hydraulic Parameters on Lower Dockum Heads
Transient Model ResultsTransient Model Results
Simulated Head in Upper Dockum
1980Predevelopment
Simulated Head in Upper Dockum
19971990
Simulated Head in Lower Dockum
1980Predevelopment
Simulated Head in Lower Dockum
19971990
Stream Gain/loss
19971990
Streams and Rivers – Gain/Loss Studies
Miles
0 10 20
Borden
Garza
Kent
Scurry
NolanMitchell
Sterling
Howard
Fisher
CrosbyDickens
Dawson
Lynn
Glasscock Coke
Stream-FlowStudy Number(s)
37-3942-4445-4852
08123720
08123800
08117995
0811
9500
08120700
08121000
Aquifer Downdip Limit
County Boundaries
Dockum Aquifer
Fresh-Water Outcrop
High-TDS Outcrop
Downdip
Model Boundary
Streamflow-Gaging Station08123720
Slade et al., (2002)
Simulated vs. Observed Stream Gain/Loss
Note: positive denotes gain and negative denotes loss
-300
-250
-200
-150
-100
-50
0
50
100
150
200
Studies37,38,39
Studies45,46,47,48
Study 42 Studies43,44,52
Gai
n/Lo
ss (A
FY/m
ile)
SimulatedStudy AStudy BStudy CStudy D
Spring Flow
19971990
Spring Issues
Many springs exhibit flow, however, some larger flows cannot be matchedLowering spring elevation or increasing conductance does not alleviate problem for larger springsWater is not being thieved by ET or streamsModel inflows from recharge and from overlying younger units are consistent with the conceptual modelSprings may be fed by high K seams/channels that are sub model-scale and cannot be simulated
ET Flow
19971990
ET Issues
Calculated ETmax ranged from 32 to 52 in/yrWith very large ET drain conductances, a maximum of 18 in/yr was simulated and generally much lessET flow is insensitive to drain conductanceThe Dockum formation is the limiter to ET flowsThe solver cannot handle relatively large rates being drawn from ET cells– Cells dry out– Rewet option is invoked resulting in convergence issues
Flow into Top of Dockum
1980Predevelopment
Flow into Top of Dockum
19971990
Flow from Storage in Upper Dockum
19971990
Flow from Storage in Lower Dockum
19971990
pre-development Inflow Outflow Net(AFY) (AFY) (AFY)
Recharge 24,837 0 24,837 0.17 in/yrX-Formational Upper 38,617 18,596 20,020 0.015 in/yrX-Formational Lower 57,601 33,921 23,680 0.020 in/yrStreams 10,633 39,690 -29,056Springs 0 1,446 -1,446Evapotranspiration 0 38,044 -38,044Wells Upper 0 0 0Wells Lower 0 0 0Storage Upper 0 0 0Storage Lower 0 0 0Total 131,688 131,697 -9Discrepancy -0.01%
Dockum Mass Balance – pre-D & 1980
1980 Inflow Outflow Net(AFY) (AFY) (AFY)
Recharge 87,167 0 87,167 0.58 in/yrX-Formational Upper 38,384 41,476 -3,092 -0.002 in/yrX-Formational Lower 74,737 31,573 43,164 0.036 in/yrStreams 9,235 46,368 -37,133Springs 0 1,475 -1,475Evapotranspiration 0 46,996 -46,996Wells Upper 0 9,713 -9,713Wells Lower 0 39,083 -39,083Storage Upper 17,516 2,316 15,200Storage Lower 29,666 37,551 -7,885Total 256,705 256,551 155Discrepancy 0.06%
Dockum Mass Balance – 1990 & 19971990 Inflow Outflow Net
(AFY) (AFY) (AFY)Recharge 87,167 0 87,167 0.58 in/yrX-Formational Upper 38,077 49,254 -11,178 -0.008 in/yrX-Formational Lower 69,664 33,847 35,818 0.030 in/yrStreams 9,046 47,153 -38,106Springs 0 1,478 -1,478Evapotranspiration 0 49,220 -49,220Wells Upper 0 8,729 -8,729Wells Lower 0 26,878 -26,878Storage Upper 17,918 1,634 16,284Storage Lower 35,835 39,481 -3,645Total 257,707 257,673 34Discrepancy 0.01%
1997 Inflow Outflow Net(AFY) (AFY) (AFY)
Recharge 87,167 0 87,167 0.58 in/yrX-Formational Upper 38,312 52,737 -14,426 -0.011 in/yrX-Formational Lower 70,810 33,989 36,820 0.031 in/yrStreams 8,932 47,547 -38,615Springs 0 1,478 -1,478Evapotranspiration 0 50,087 -50,087Wells Upper 0 9,197 -9,197Wells Lower 0 29,955 -29,955Storage Upper 18,735 1,624 17,111Storage Lower 40,898 38,217 2,681Total 264,854 264,833 21Discrepancy 0.01%
Transient Water Balance – Outcrop
Flows within Outcrop
-60000
-40000
-20000
0
20000
40000
60000
80000
100000
1940 1950 1960 1970 1980 1990 2000Year
Rec
harg
e/D
isch
arge
(AFY
)
RechargeRecharge from StreamsStream DischargeSpring DischargeET Discharge
Transient Water Balance – Subcrop
Flows within Lower Dockum
-80000
-60000
-40000
-20000
0
20000
40000
60000
80000
100000
1940 1950 1960 1970 1980 1990 2000Year
Rec
harg
e/D
isch
arge
(AFY
)
X-formational RechargeFrom StoragePumpingTo StorageX-formational Discharge
Transient Water Balance – Subcrop
Flows within Upper Dockum
-60000
-40000
-20000
0
20000
40000
60000
1940 1950 1960 1970 1980 1990 2000Year
Rec
harg
e/D
isch
arge
(AFY
)
X-formational RechargeFrom StoragePumpingTo StorageX-formational Discharge
Model Conclusions
Recharge within the outcrop and cross-formational flow from younger formations are the largest sources of inflow to Dockum followed by stream lossesPumping, evapotranspiration, and stream gains are the significant discharge mechanismsModel is sensitive to KH of Lower Dockum and GHB headUpper Dockum heads are sensitive to KV of Upper DockumSurface water discharge is sensitive to KH of Lower Dockum, recharge and specific BC elevations
Model Limitations
Dockum is a “minor” aquifer underlying “major”aquifersRegional model with groundwater availability prediction applicable at approximately county scaleTemporal stress periods of one year preclude prediction of short-term head/flow variabilityThe model does not provide a rigorous solution to surface water modelingLarge portions of the Upper Dockum unconstrained by observed water-level data
GAM Schedule
Project start – May 24, 2006Draft concept. Model mtg. – April 26, 2007Draft conceptual model report – May 16, 2007Steady-state model calibration mtg. – March 28, 2008Transient calibration & verification mtg. – May 20, 2008SAF3 Model calibration – June 4, 2008 Draft Model Report to TWDB – June 30, 2008TWDB feedback on Draft Report – August 31, 2008Post draft final report review mtg. – September 2008Model Training Seminars – September 2008Final Model Report to TWDB – October 31, 2008
Dockum GAM 3rd Stakeholder Advisory Forum
June 4, 2008
Lubbock, TX
Name Affiliation
Melanie Barnes LWV
Ray Brady RMBJ Geo Inc.
H.P. “Bo” Brown Region D
Jason Coleman South Plains UWCD
Steve and Nan Coneway City of Hereford
Jim Conkwright HPWD
Amy Crowell PGCD
Harvey Everheart Mesa UWCD
John Ewing INTERA
Michelle Guelker Lone Wolf GCD
Kevin Hopson DBS&A
Ian Jones TWDB
Mike McGregor Llano Estacado UWCD
Bret Mills Security State Bank
John Pickens INTERA
Don M. Reynolds HPWD
Julie Weathers TTUHSC
Ben Weinheimer TCFA
Chris Wingert CRMWD
Dockum Aquifer GAM 3rd Stakeholder Advisory Forum
Comments and Responses June 4, 2008
Lubbock, Texas
Questions and Answers:
Q. Flow data control points – where available to define the Dockum structure contours?
A. We have the data control points in the figure used in the Conceptual Model Report and this level of detail will be provided in the Final Report.
Q. Moore County – are they combined, Ogallala and Dockum wells?
A. Yes, likely. We attempted to remove dual completion wells from model calibration.
Q. Have Santa Rosa wells drilled in Deaf Smith County in past 5 to 7 years been included in the model?
A. Yes, if the well property data has been submitted to the TWDB for posting on their website prior to our downloading of TWDB database for development of conceptual model report.
Note that the model calibration period is from 1980 to 1997, so water level data from last 5 to 7 years would not be included, but prior data would be included.
Details on the database and conceptual model were presented at SAF2 and a CM report was prepared and posted. All data will be included in the Final Report.
Q. What is the source of pumping data in NM?
A. Numbers for pumping by county were taken from either the New Mexico Office of the State Engineer (NM OSE) (for 1975, 1980, 1990, 1995, and 2000) or the USGS (for 1985). Irrigation and Livestock pumping was distributed by land use type from the National Land Cover Data (NLCD) map. Rural Domestic pumping was distributed by population density. Municipal, Industrial, and Manufacturing well locations were taken from the NM OSE. For Dockum/Ogallala and Dockum/Pecos wells, 25% of the pumping was applied to the Dockum.
Q. Question on the reliability of the 5,000 mg/l aquifer limit definition.
A. There is sufficient data to reasonably define the 5,000 mg/L TDS boundary. The location is uncertain and based on limited data in some areas, however. It is a gradual decline in concentration from 5,000 mg/L and, because the high TDS area is being included in the active model domain, it is really only a qualitative threshold for reference rather than anything included in the MODFLOW model.
1
Q. For Deaf Smith County model area, should pumping be in Lower Dockum rather than Upper Dockum?
A. Yes. After reviewing the methodology for pumping layer assignments, it became clear that all the pumping applied to the Upper Dockum throughout the entirety of the model domain should be applied instead to the Lower Dockum. Because of the relatively small amount of this pumping, the change had minimal impact on the model results.
Q. What does “Water is not thieved by ET or streams” mean?
A. This was just one of the tests to identify the mechanisms limiting spring flow in the model. It turns out that the Dockum aquifer properties (not the spring properties or nearby stream and ET properties) limit the spring discharge rate in the model. We are aware that ET occurs in reality and have included it in the model for this reason.
Q. Deaf Smith County pumping issue?
A. See prior answer regarding reassignment of pumping to Lower Dockum.
Q. Should there be a separation of Upper and Lower Dockum?
A. While there may be uncertainty in the interface between the Upper and Lower Dockum, the two units have significant differences in hydraulic properties and stresses. By separating the two units into model layers, a more accurate representation of the conceptual model is possible.
Q. If asked to look at decline of 1 ft, 2 ft, etc. per year in Deaf Smith County, how usable is model?
A. It is applicable to apply the model at the county scale. However, limited water level data in Deaf Smith county during the calibration period means that the model is not well constrained by data in that area.
Q. Good to include high TDS region in model because of future desalinization potential. Should there be caution in using data points 80 miles apart?
A. This area of the model is certainly poorly constrained data. However, the model imposes physical constraints based on the reasonable estimates of hydraulic properties and structure and the equations governing groundwater flow so it may be a useful estimation tool. It should be noted, though, that MODFLOW does not account for density dependant flow as a function of salinity.
2
Q. We would like to see where data is limited (e.g., dashed lines).
A. In the Final Report attention will be given to clearly delineate areas where data is insufficient for contouring.
Q. Can we use more color consistency between figures showing similar information?
A. In the Final Report we will attempt to provide consistent color scales between all comparable figures so that they may be more efficiently compared visually.
3
