Snow.
The Belle Fourche River basin has 69 percent of normal SWE. The basin SWE is 87 percent of what it was last year. See Basin summary of Snow Course Data at the beginning of this report for a detailed listing.
Precipitation.
Precipitation, for the month of February was 151 percent of average in the Black Hills (104 percent of last February). Monthly percentages range from 54 to 370 percent. Year-to-date precipitation is 82 percent of average and 47 percent of last year's amount. Year to date percentages range from 46 to 137. This is from the 4 reporting stations.
Reservoir.
Reservoir storage is above average in the basin. Angostura is currently storing 112 percent of average (113,600-acre feet). Belle Fourche reservoir is storing 154 percent of average (173,600-acre feet). Deerfield reservoir is storing 111 percent of average (14,700-acre feet). Keyhole reservoir is storing 170 percent of average (173,500-acre feet). Pactola reservoir is storing 118 percent of average (54,100-acre feet), and Shadehill reservoir is storing 107 percent of average (53,500-acre feet).
Streamflow
Streamflow forecast are below average as of March 1. Deerfield Reservoir inflow is forecast at 3150 acre feet (64 percent of average). Pactola is forecast at 11800 acre feet (56 percent of average). This is for the March - July forecast period.
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BELLE FOURCHE & CHEYENNE RIVER BASINS
Streamflow Forecasts - March 1, 2000
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| <<====== Drier ====== Future Conditions ======= Wetter =====>> |
| |
Forecast Point Forecast | ==================== Chance Of Exceeding * ====================== |
Period | 90% 70% | 50% (Most Probable) | 30% 10% | 30-Yr Avg.
| (1000AF) (1000AF) | (1000AF) (% AVG.) | (1000AF) (1000AF) | (1000AF)
====================================================================|=======================|=====================================
DEERFIELD RESERVOIR Inflow MAR-JUL 0.17 1.95 | 3.15 64 | 4.35 6.13 4.90
| |
PACTOLA RESERVOIR Inflow MAR-JUL 3.1 4.6 | 11.8 56 | 19.0 30 21
| |
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BELLE FOURCHE & CHEYENNE RIVER BASINS | BELLE FOURCHE & CHEYENNE RIVER BASINS
Reservoir Storage (1000 AF) - End of February | Watershed Snowpack Analysis - March 1, 2000
==================================================================================================================================
Usable | *** Usable Storage *** | Number This Year as % of
Reservoir Capacity| This Last | Watershed of =================
| Year Year Avg | Data Sites Last Yr Average
========================================================================|=========================================================
ANGOSTURA 122.1 113.6 120.9 101.7 | BELLE FOURCHE 7 85 69
|
BELLE FOURCHE 178.4 173.6 167.4 113.0 |
|
DEERFIELD 15.2 14.7 14.8 13.2 |
|
KEYHOLE 193.8 173.5 178.6 101.9 |
|
PACTOLA 55.0 54.1 52.0 46.0 |
|
SHADEHILL 81.4 53.5 69.7 50.0 |
|
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* 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.
The average is computed for the 1961-1990 base period.
(1) - The values listed under the 10% and 90% Chance of Exceeding are actually 5% and 95% exceedance levels.
(2) - The value is natural volume - actual volume may be affected by upstream water management.
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