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Pablo
Ronan
Dixon
Arlee
MarionSomers
Polson
Charlo
Bigfork
Whitefish
Kalispell
Swan Lake
Hot Springs
St Ignatius
West Glacier
Columbia Falls
Legend
LakesStreams
Cities or townsStudy areaCounty boundaries
Legend
Generalized geology
Statewide ground-watermonitoring network wellsWells visited during the Flathead Lake Ground-Water Characterization Study
Alluvium alongmajor drainagesGlacial depositsTertiary basin fill
Map F. Geographic and cultural features
Map G. Generalized geology, statewide monitoring wells, and wells visited duringthe Flathead LakeGround-Water Characterization Study
Legend
Map B. Well density per section in 1980
01 - 1011 - 30
31 - 5051 - 80
Number of well recordsper section:
NO OUTLINE
Map A. Well density per section in 1970
LegendNumber of well recordsper section:
NO OUTLINE 0
31 - 5051 - 80
LegendNumber of well recordsper section:
LegendNumber of well recordsper section:
LegendNumber of well recordsper section:
NO OUTLINE 0
1 - 1011 - 3031 - 5051 - 8081 - 160
NO OUTLINE 0
1 - 1011 - 3031 - 5051 - 8081 - 160
NO OUTLINE 0
1 - 1011 - 3031 - 5051 - 8081 - 160
51 - 8081 - 160
Legend
Number of well recordsper section:
Map C. Well density per section in 1990
Map D. Well density per section in 2000 Map E. Well density per
section in 2005
Map H. Distribution of alluvium, sections with over 50 wells (2005), and selectedhydrographs
FLATHEAD LAKE
HUNGRY HORSE RES.
North Fork Flathead R.
Middle Fork Flathead R.South Fork Flathead R.
Flathe
ad R.
Stillwater R.
Whitefish R.
Swan R.
Flathe
ad R.
Flathead R.
Jocko R.
Little Bitterroot R.
LAKEMCDONALD
WHITEFISH LAKE
ASHLEY LAKE
LITTLE BITTERROOT LAKE
SWAN LAKE
Montana Bureau of Mines and GeologyA Department of Montana Tech of The University of Montana
Ground-Water Open-File Report 19, Sheet 1 November, 2007
Sheet 1. The number of water wells per section in 1970, 1980, 1990, 2000, and 2005.
0 10 205Miles. . 0 10 205
Miles . 0 10 205Miles . 0 10 205
Miles . 0 10 205Miles
.
0 10 205Miles
.
0 10 205Miles
.
0 10 205Miles
The study area is defined by the Flathead Lake Ground-Water Characterization Area (LaFave and others, 2004). Maps A through E illustrate the number of water-well records per Public Land Survey System (PLSS) section in 10-year increments beginning in 1970 and include water-well records present in the GWIC database at the beginning of each stated year. Figure 1 (below) shows the progression graphically through 2005. While the number of PLSS sections with at least one well is increasing, the total number of wells is increasing at a much greater rate (note the separate scales in Figure 1). Throughout the map series, some PLSS sections that have small numbers of wells in non-valley locations result from in-correctly located wells in GWIC.Map F shows selected lakes, streams, cities, towns, and counties within the study area.Map G illustrates the general geology within the intermontane basins, locations of wells visited during the Flathead Lake Ground-Water Characterization Study, and the locations of statewide ground-water moni-toring wells. Comparison of the locations of visited and statewide monitoring network wells with the PLSSsection well densities shown on maps D and E shows that data from the visited wells and water-level records from the monitoring network are relevant to the most developed aquifers. These aquifers typically include large thicknesses of valley-fill aquifer materials. The alluvium shown on Map G includes largely surficial, generally unconsolidated sediments that are in relatively good hydrologic connection with surface water.Map H shows PLSS sections that contained more than 50 wells in 2005, the alluvial aquifers, and hydro-graphs from selected statewide monitoring wells. The hydrographs show ground-water storage or pressure change in some of the most used aquifers.
ReferencesLaFave, J.I., Smith, L.N., and Patton, T.W., 2004, Ground- water resources of the Flathead Lake Area: Flathead, Lake, and parts of Missoula and Sanders Counties: Part A- Descriptive overview: Montana Bureau of Mines and Geology Ground-Water Assessment Atlas 2A, 132 p.
Natural Resource Information System, Montana State Library, for base map coverages (http://nris.mt.gov/).
Explanation
Introduction
AcknowledgmentsThis report is primarily funded by a Montana Department of Natural Resources and Conservation grant obtained by the Clark Fork Basin Task Force, a voluntary citizen's group functioning as a consensus-based, collaborative watershed advisory committee.
These maps are based on data from the Montana Ground-Water Information Center (GWIC) database(http://mbmggwic.mtech.edu/), and display how ground water has been developed in the Flathead Lake Ground-Water Characterization Area. F L A T H E A D
L A K E
Alluvium
S A N D E R S
MISSOULAMajor highwaysTownship boundaries
Scale 1:792,000
Scale 1:792,000
Scale 1:792,000_̂
T37N
T33N
T29N
T24N
T20N
T15N
R25W
R21W
R18W
T35N
T29N
T24N
T20N
R16W
R21W
R24W
!
952 sections with at least one wellTotal number of wells in study area: 3,421
1,295 sections with at least one well
Total number of wells in study area: 6,894
1,486 sections with at least one wellTotal number of wells in studyarea: 10,296
SCALE 1:1,000,000 SCALE 1:1,000,000 SCALE 1:1,000,000 SCALE 1:1,000,000
1 - 1011 - 30
By Kirk B. Waren and Thomas W. Patton
Ground-Water Resource Development in the Flathead Lake Ground-Water Characterization Area, Flathead, Lake, Missoula, and Sanders Counties, Montana
1,842 sections with at least one wellTotal number of wells in studyarea: 18,327
SCALE 1:1,000,000
s
Cities or towns (see Map F)
Bedrock
As of 2005, 47 sections within the Flathead Lake Ground-Water Characterization Area had more than 50 wells. Of those, 43 sections intersected the alluvium. Eight of these sections are completely within the alluvium. Long-term water-level records from selected monitoring wells are shown in the inset graphs.
Well 85689T30N, R20W, Section 22, CDAC, Total Depth 308 ft.
3000
3010
3020
3030
3040
1/1/1992 1/1/1996 1/1/2000 1/1/2004 1/1/2008DATE
GROU
ND-W
ATER
ELE
VATIO
N (FT
)
Well 85628T30N, R20W, Section 20, DCCA, Total Depth 149 ft.
2940
2950
2960
2970
2980
2990
1/1/1992 1/1/1996 1/1/2000 1/1/2004 1/1/2008DATE
GROU
ND-W
ATER
ELE
VATIO
N (FT
)
Well 148189T30N, R20W, Section 19, DAAC, Total Depth 342 ft.
2950
2960
2970
2980
1/1/1992 1/1/1996 1/1/2000 1/1/2004 1/1/2008DATE
GROU
ND-W
ATER
ELE
VATIO
N (FT
)
Well 6419T28N, R21W, Section 4, DCDA Total Depth 23 ft.
2890
2900
2910
2920
1/1/1984 1/1/1988 1/1/1992 1/1/1996 1/1/2000 1/1/2004 1/1/2008DATE
GROU
ND-W
ATER
ELE
VATIO
N (FT
)
Montana Ground-Water Information Center, Montana Bureau of Mines and Geology, Montana Tech of The University of Montana (http://mbmggwic.mtech.edu/).
1,710 sections with at least one wellTotal number of wells in studyarea: 15,050
R11W
R16W
5 Cities or towns (see Map F)
Figure 1. GWIC database records for wells within the Flathead Lake Ground-Water
Characterization Area
0
5,000
10,000
15,000
20,000
1960 1970 1980 1990 2000 201005001,0001,5002,0002,500
Total number of wellrecordsNumber of sectionswith at least one well
Well 131524T29N, R21W, Section 20, CCCC, Total Depth 278 ft.
2880
2890
2900
2910
2920
2930
1/1/1962 1/1/1970 1/1/1978 1/1/1986 1/1/1994 1/1/2002DATE
GROU
ND-W
ATER
ELE
VATIO
N (FT
)