Table 5. Results of Indicators of Hydrologic Alteration analysis for the Salt River at New London, Missouri. Range of Variability Approach (RVA) targets are based on + or - 1 standard deviation of pre-dam means, except when targets fall outside of pre-dam range limits. When this occurred, the 25th (lower target) or 75th (upper target) percentiles were used. Streamflows in cubic feet per second. * indicate post-dam means falling outside of RVA targets.
Parameter Pre-Impact Mean Post-Impact Mean RVA Targets Percent of Years Outside of RVA Targets
Monthly Flow
October 1020 1415 29-2934 14
November 930 1861 42-2377 29
December* 755 2726 49-1828 36
January 1141 1380 65-2495 29
February 1812 1467 177-3447 7
March 2393 2910 439-4348 36
April 2947 2798 680-6035 36
May 2328 2734 382-5135 29
June 2529 2821 546-5214 36
July 1500 2218 189-4055 43
August 895 1333 166-2501 21
September 1053 1220 84-3284 14
Min/Max Flows
1-day minimum* 17 38 0-34 50
3-day minimum* 18 41 0.5-36 64
7-day minimum* 20 49 0.8-39 64
30-day minimum* 46 139 7-102 43
90-day minimum 165 375 27-381 29
1-day maximum* 28167 11879 14437-41897 71
3-day maximum* 24110 11307 11784-36436 50
7-day maximum 16029 10686 7554-24505 29
30-day maximum 7139 7885 317-24505
90-day maximum 3918 5043 1819-6017 36
# of zero days 0.5 0 0-3 0
Base flow 0 0 0-0 43
Day of year minimum flow 263 278 239-287 64
maximum flow* 140 176 109-170 86
Low pulse count 6 8 3-9 64
Low pulse duration 11 6 5-18 79
High pulse count 7 6 4-11 43
High pulse duration* 3 6 2-4 71
low pulse threshold is 65 (25th percentile)
high pulse threshold is 5878 (+1 sd)
Rise rate 1352 759 614-2090 21
fall rate -596 -565 -934- -257 7
# of reversals* 84 155 72-96 93

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