USDA Forest Service Boise Aquatic Sciences Lab - Rocky Mountain Research Station

 

 

Boise Aquatic Sciences Lab
322 East Front Street
Suite 401
Boise, ID  83702

(208) 373-4340
(208) 373-4391 (FAX)

United States Department of Agriculture Forest Service.

USDA Link Forest Service Link

 

Streamflow Data

The Boise Database consists of files of climatic and streamflow data from the Silver Creek Study Area (see below) and the Horse Creek Study Area in Idaho. Also included are average daily streamflow data (1955-1997) for Benton Creek (Priest River Experimental Forest, northern Idaho).

 

There are other data available from various agencies and different locations at the Climatological and Hydrological Data Access page.

 

 

Silver Creek Study
General Study Information

The Silver Creek administrative-research study, was designed and initiated in the mid-1960's to determine feasible methods to provide access to and harvest the timber resource on granitic soils in mountainous terrain. The evaluation of erosion and hydrologic consequences of various forest management activities was conducted by the Rocky Mountain Research Station and the Intermountain Region of the U.S. Forest Service. The study area is underlain with intrusive granites of the Idaho batholith. Much of the 40,000 km2 Idaho batholith has cohesionless coarse-grained soils that are highly erodible, especially when disturbed. The combination of erodible soils, relatively high climatic stresses from summer convective rainstorms and rapid spring snowmelt runoff, and mountainous terrain creates a high potential for increases in erosion and stream sedimentation following ground-disturbing activities.

 

open book graphic Publications

 

 

Location

The study area is located in the mountains of central Idaho in the Silver Creek drainage on the Boise National Forest. Silver Creek is a tributary to the Middle Fork of the Payette River. The approximate center of the study area is 44° 25' N latitude and 115° 45' W longitude. Elevations on the study watersheds range from about 1389 m to 2067 m.

 

Physiography

Physiographic characteristics of these headwater drainages are typical of mid-elevation fluvial landscapes of the Idaho batholith, with V-shaped valleys and steep slopes. Side slopes are steep with slopes ranging from 25 to 75 percent. Additional watershed characteristics are provided in the following table.

 

Watershed
Name

Watershed
Number
Area
(ha)
General
Aspect
(o)
Maximum
Elevation
(m)
Minimum
Elevation
(m)
Channel
Length
km
Drainage
Density
(km/km2)
Relief
Ratio
(m/m)
                 
C
SC1
186
125
2073
1490
3.7
2.0
0.25
D
SC2
117
121
2067
1477
3.1
2.6
0.25
Eggers
SC3
128
127
2006
1444
3.5
2.7
0.24
Ditch
SC4
101
149
1839
1426
2.4
2.4
0.24
Cabin
SC5
109
136
1745
1389
2.9
2.7
0.19
Control
SC6
161
142
1778
1414
5.0
3.0
0.19
K1
SC7
22
291
1820
1418
0.8
3.5
0.36

 

Forest Vegetation

Timber types vary from nearly pure stands of ponderosa pine (Pinus ponderosa Laws.) in the lower elevations and south-facing slopes to mixed ponderosa pine and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) at the middle elevations and stands of Douglas-fir and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in the upper reaches. There are limited areas of lodgepole pine (Pinus contorta Dougl. Ex Loud.) on the flat and poorly drained areas along Silver Creek. The two principal vegetation habitat types (Steele et al., 1981) are Douglas fir/white spirea, ponderosa pine phase and Douglas-fir/ninebark, ponderosa phase. Much of this timber is mature to overmature. There had been no previous timber harvest program on National Forest lands in this drainage at the initiation of this study.

 

Geology

The watersheds are located within the southern Idaho batholith section of the Northern Rocky Mountain Province (Fenneman, 1931). Bedrock is a uniform, medium to coarse-grained biotite granodiorite that is moderately to well weathered (Clayton et al., 1979; Clayton, 1986).
 

Soils

Soils are generally weakly developed with A horizons ranging from 5 to 25 cm thick overlying moderately weathered granitic parent material. Soil textures are loamy sands to sandy loams and depth to bedrock is usually less than 1.0 m. Soils less than 20 cm deep are common on ridges and south slopes. Scattered outcrops of granitic bedrock are found in the upper elevations of the watersheds. Four predominant types of soils are found on the watersheds. Sandy-skeletal, mixed Typic Xerorthents predominate on south slopes. Sandy-skeletal, mixed Typic Cryorthents, sandy-skeletal mixed Typic Cryoborolls, and mixed Alfic Cryopsamments are found at other locations (Clayton and Kennedy, 1985).

 

Climate

Average annual precipitation on these watersheds is approximately 1020 mm. Summers are hot and dry with occasional convective storms that are often quite localized. Snowfall accounts for about 65% of the annual precipitation and the average maximum snowpack water equivalent accounts for slightly over half the average annual precipitation. The spring snowmelt dominates the annual hydrograph with peak streamflows typically occurring in March through May.

 

References

Clayton, J.L., W.F. Megahan, and D. Hampton. 1979. Soil and Bedrock Properties - Weathering and Alteration Products and Processes in the Idaho Batholith. USDA For. Serv. Res. Paper. INT-237, 35 pp.

 

Clayton, J.L. 1986. An Estimate of Plagioclase Weathering Rate in the Idaho Batholith Based      upon Geochemical Transport Rates. In: Coleman, S.M.; Dethier, D.P., editors. Rates of      chemical weathering of rocks and minerals. Orlando, FL: Academic Press: 1986: 453-466.

 

Clayton, J.L. and D.A. Kennedy. 1985. Nutrient Losses from Timer Harvest in the Idaho Batholith. Soil Sci. Soc. Amer. J. 49:1041-1049.

 

Fenneman, N.M. 1931. Physiography of Western United States. McGraw-Hill Book Company, Inc. New York. 534p.

Steele, R., R.D. Pfister, R.A. Ryker and J.A. Kittams. 1981. Forest Habitat Types of Central Idaho. USDA, For. Serv. Gen. Tech. Rep. INT-114.

 

water droplet graphicStreamflow Data


 

water droplet graphicClimatic Data


 
 

USDA Forest Service - RMRS - Boise Aquatic Sciences Lab
Last Modified:  Monday, 02-Jul-2018 11:45:35 CDT


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