Subject
Water resources development
Water-supply
304
Groundwater
121
Hydrology
100
Water-supply Management
90
Water quality
75
Watershed management
45
Water quality management
44
Water use
43
Irrigation
34
Water rights
34
Environmental engineering
32
Dredging
31
River engineering
31
Stream measurements
31
Colorado River Watershed (Colo.-Mexico)
24
Aquifers
23
Flood control
23
Mines and mineral resources
23
Groundwater Quality
22
Hydrology Research
22
Sustainable development
21
Water conservation
21
Hydrogeology
20
Climatic changes
19
Hydroelectric power plants
18
Hydrological stations
17
Dams
15
Water Law and legislation
15
Federal aid to water resources development
14
Reservoirs
13
Resource allocation
13
Water Pollution
13
Hydraulic engineering
12
Land use
12
Reclamation of land
12
Geology
11
Stream conservation
11
Groundwater Pollution
10
Infrastructure (Economics)
10
Natural resources
10
Water consumption
10
Water reuse
10
Water-supply Political aspects
10
Colorado River (Colo.-Mexico)
9
Water resources development Government policy
9
Water-supply Government policy
9
Appropriations and expenditures
8
Drinking water
8
Water Storage
8
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