05451700 Timber Creek Near Marshalltown, Iowa

IOWA RIVER BASIN 05451700 TIMBER CREEK NEAR MARSHALLTOWN, IOWA

LOCATION.--Lat 42°00'32", long 92°51'08" referenced to North American Datum of 1927, in NW 1/4 SW 1/4 SE 1/4 sec.08, T.83 N., R.17 W., Marshall County, IA, Hydrologic Unit 07080208, on left bank 20 ft upstream from bridge on Shady Oaks Road, 3.0 mi southeast of Marshalltown, and 3.6 mi upstream from mouth.

DRAINAGE AREA.--118 mi².

PERIOD OF RECORD.--Discharge records from October 1949 to current year.

GAGE.--Water-stage recorder. Datum of gage is 849.44 ft above National Geodetic Vertical Datum of 1929. Prior to October 1, 1991, at site 700 ft upstream at same datum.

EXTREMES OUTSIDE PERIOD OF RECORD.--Flood in June 1947 reached a stage of 16.8 ft, discharge 5,700 ft³/s.

A summary of all available data for this streamgage is provided through the USGS National Water Information System web interface (NWISWeb). The following link provides access to current/historical observations, daily data, daily statistics, monthly statistics, annual statistics, peak streamflow, field measurements, field/lab water-quality samples, and the latest water-year summaries. Data can be filtered by parameter and/or dates, and can be output in various tabular and graphical formats.

http://waterdata.usgs.gov/nwis/inventory/?site_no=05451700

The USGS WaterWatch Toolkit is available at:

http://waterwatch.usgs.gov/?id=ww_toolkit

Tools for summarizing streamflow information include the duration hydrograph builder, the cumulative streamflow hydrograph builder, the streamgage statistics retrieval tool, the rating curve builder, the flood tracking chart builder, the National Weather Service Advanced Hydrologic Prediction Service (AHPS) river forecast hydrograph builder, and the raster- hydrograph builder. Entering the above number for this streamgage into these toolkit webpages will provide streamflow information specific to this streamgage.

1 IOWA RIVER BASIN 05451700 TIMBER CREEK NEAR MARSHALLTOWN, IOWA

A description of the statistics presented for this streamgage is available in the main body of the report at:

http://dx.doi.org/10.3133/ofr20151214

A link to other streamgages included in this report, a map showing the location of the streamgages, information on the programs used to compute the statistical analyses, and references are included in the main body of the report.

Statistics Based on the Entire Streamflow Period of Record

05451700 Monthly and annual flow durations, based on 1950–2013 period of record (64 years) Percentage of days Di Annual flow discharge equaled or sc durations exceeded ha rg e (c ub 4 IOWA RIVER BASIN 05451700 TIMBER CREEK NEAR MARSHALLTOWN, IOWA ic fe et pe r se co nd ) Kentau Fe statisti Oct Nov Dec Jan b Mar Apr May June July Aug Sept Annual c 0. 99 0.60 1.0 0.37 0.06 30 3.3 2.2 2.2 0.60 0.40 0.64 0.90 0.50 0.297 0. 98 0.80 1.2 0.50 0.26 60 3.6 3.4 2.9 1.1 0.87 1.2 1.1 0.80 0.288 2. 2. 95 1.5 1.6 0.80 0.42 0 4.9 6.1 5.9 4.7 2.5 2.0 1.8 0 0.291 3. 3. 90 2.6 2.7 1.9 1.5 4 10 9.5 10 13 6.5 4.0 2.5 6 0.282 5. 5. 85 3.5 3.8 3.1 3.0 0 15 16 19 19 13 5.8 3.3 6 0.259 6. 7. 80 4.6 5.0 4.7 3.9 6 20 22 30 28 17 7.8 4.2 9 0.264 9. 75 5.8 6.6 6.0 5.2 0 25 29 38 36 22 11 5.8 10 0.257

70 7.1 8.6 7.5 7.0 12 30 38 45 49 28 13 7.4 14 0.258

65 8.8 11 9.0 8.0 16 38 46 57 62 34 15 8.8 18 0.253

60 10 14 11 10 25 45 54 69 71 41 18 10 23 0.239

55 12 17 13 14 30 51 62 80 82 47 21 12 29 0.235

50 15 21 18 19 35 57 70 91 96 54 24 14 35 0.225

45 19 27 23 25 39 65 82 102 110 60 27 17 42 0.223

40 22 32 30 31 45 77 92 117 128 68 30 19 50 0.224

35 25 37 37 36 52 93 106 133 145 76 34 23 59 0.245

30 34 43 44 40 58 109 127 156 164 86 40 27 70 0.257

25 42 55 50 45 66 132 151 181 186 97 47 34 85 0.278 8 20 54 66 56 52 0 170 181 210 218 113 57 42 105 0.288 10 15 74 81 64 62 6 221 213 256 265 132 70 53 136 0.278 15 10 110 98 79 75 1 328 269 328 355 171 98 74 188 0.282 30 5 164 149 110 100 9 647 374 458 645 294 181 144 309 0.217 72 2 249 206 174 167 0 1,080 623 770 1,180 589 438 294 583 0.147 5 IOWA RIVER BASIN 05451700 TIMBER CREEK NEAR MARSHALLTOWN, IOWA

1, 10 1,45 1 353 290 230 270 0 1,500 923 0 1,740 977 650 471 933 0.105

05451700 Annual exceedance probability of instantaneous peak discharges, in cubic feet per second (ft3/s), based on the Weighted Independent Estimates method,

95- 95- percent percent Annual lower upper exceed- Recur- confi- confi- ance rence dence dence probabilit interval Discharge interval interval y (years) (ft3/s) (ft3/s) (ft3/s) 0.500 2 2,590 2,150 3,140 0.200 5 4,820 4,020 5,780 0.100 10 6,600 5,450 7,980 0.040 25 9,210 7,430 11,400 0.020 50 11,200 8,750 14,200 0.010 100 13,100 9,920 17,300 0.005 200 15,800 11,500 21,700 0.002 500 17,900 12,400 25,800 and based on the expected moments algorithm/multiple Grubbs-Beck analysis computed using a historical period length of 67 years (1947–2013) 0.500 2 2,590 2,110 3,150 0.200 5 4,800 3,950 5,930 0.100 10 6,460 5,280 8,310 0.040 25 8,710 6,930 12,100 0.020 50 10,500 8,080 15,600 0.010 100 12,300 9,120 19,700 0.005 200 14,100 10,100 24,500 0.002 500 16,600 11,200 32,000 Kentau statistic 0.030 P-value 0.732 Begin year 1950 End year 2013 Number of peaks 64

05451700 Annual exceedance probability of high discharges, based on 1950–2013 period of record (64 years) Recur- Maximum average discharge (ft3/s) for Annual rence indicated number of consecutive days exceedance interval probability (years) 1 3 7 15 30 0.990 1.01 137 81 46 26 18 0.950 1.05 328 202 120 73 51 0.900 1.11 497 310 188 118 83 0.800 1.25 789 496 306 198 139 0.500 2 1,680 1,050 659 437 307 0.200 5 3,060 1,860 1,170 772 535 0.100 10 3,950 2,350 1,470 960 660 0.040 25 4,980 2,890 1,790 1,150 784 0.020 50 5,670 3,230 1,990 1,260 853 0.010 100 6,300 3,520 2,150 1,350 908 0.005 200 6,860 3,770 2,290 1,420 951 0.002 500 7,510 4,050 2,440 1,500 994 0.12 0.16 Kentau statistic 0.061 0.073 3 0 0.181 0.15 0.06 P-value 0.483 0.394 2 3 0.035

05451700 Annual nonexceedance probability of low discharges, based on April 1950 to March 2013 period of record (63 years) Annual Recur- nonexceed rence Minimum average discharge (ft3/s) for indicated number of consecutive days -ance interval probability (years) 1 3 7 14 30 60 90 120 183 0.01 100 0.00 0.00 0.00 0.02 0.06 0.23 0.40 0.51 0.71 0.02 50 0.00 0.00 0.00 0.06 0.14 0.40 0.65 0.80 1.1 0.05 20 0.01 0.13 0.20 0.21 0.40 0.85 1.3 1.5 2.1 0.10 10 0.27 0.48 0.63 0.59 0.93 1.6 2.2 2.7 3.7 0.20 5 1.1 1.3 1.6 1.7 2.3 3.3 4.2 5.1 6.9 0.50 2 5.8 5.3 5.9 7.7 8.9 11 13 15 21 0.80 1.25 15 15 16 19 23 28 35 41 54 0.90 1.11 21 23 25 26 32 43 56 64 85 0.96 1.04 26 35 37 38 42 64 89 101 133 0.98 1.02 29 43 47 48 49 81 116 132 174 0.99 1.01 31 51 56 57 58 98 147 166 219 Kentau statistic 0.238 0.244 0.259 0.267 0.271 0.240 0.233 0.234 0.217 7 IOWA RIVER BASIN 05451700 TIMBER CREEK NEAR MARSHALLTOWN, IOWA P-value 0.006 0.005 0.003 0.002 0.002 0.006 0.007 0.007 0.012

05451700 Annual nonexceedance probability of seasonal low discharges, based on October 1949 to September 2013 period of record (64 years) Annual Recur- Minimum average discharge (cubic feet per second) nonexceed- rence for indicated number of consecutive days ance interval probability (years) 1 7 14 30 1 7 14 30 January-February-March April-May-June 0.01 100 0.00 0.00 0.03 0.09 0.19 0.46 0.65 0.97 0.02 50 0.01 0.05 0.08 0.21 0.45 0.92 1.2 1.8 0.05 20 0.16 0.36 0.31 0.69 1.4 2.3 3.0 4.2 0.10 10 0.58 0.93 0.90 1.8 3.5 4.9 6.0 8.3 0.20 5 1.8 2.3 2.7 4.6 8.9 11 13 17 0.50 2 9.4 9.8 14 19 33 36 41 56 0.80 1.25 28 30 36 45 70 80 93 132 0.90 1.11 41 45 50 60 89 107 128 186 0.96 1.04 55 60 65 74 104 134 165 249 0.98 1.02 63 68 73 81 111 150 187 291 0.99 1.01 70 75 80 85 115 162 206 327 0.22 0.16 Kentau statistic 0.173 0.216 9 9 0.245 0.222 0.231 0.275 0.00 0.05 P-value 0.044 0.012 8 0 0.004 0.010 0.007 0.001 July-August-September October-November-December 0.01 100 0.00 0.29 0.42 0.80 0.00 0.00 0.20 0.33 0.02 50 0.00 0.45 0.63 1.1 0.08 0.10 0.35 0.55 0.05 20 0.66 0.85 1.1 1.8 0.40 0.50 0.76 1.1 0.10 10 1.4 1.5 1.8 2.7 0.90 1.1 1.4 2.0 0.20 5 2.5 2.8 3.3 4.5 2.1 2.5 3.0 3.9 0.50 2 7.2 8.4 9.5 12 7.8 9.2 11 13 0.80 1.25 19 23 26 31 24 27 31 36 0.90 1.11 32 37 42 51 39 43 50 59 0.96 1.04 54 59 69 87 64 69 79 96 0.98 1.02 75 78 94 123 86 90 105 128 0.99 1.01 99 100 124 167 109 112 132 164 0.23 0.22 Kentau statistic 0.224 0.230 7 2 0.213 0.219 0.231 0.218 0.00 0.01 P-value 0.009 0.007 6 0 0.013 0.011 0.007 0.011

Statistics Based on the 1984–2013 Streamflow Period of Record

05451700 Monthly and annual flow durations, based on 1984–2013 period of record (30 years) Annual flow Discharge (cubic feet per second) durations Percentage of days Kentau discharge equaled or statisti exceeded Oct Dec Jan Feb Mar Apr May June July Aug Sept Annual c 99 1.5 0.28 0.49 1.5 2.2 5.2 3.1 2.5 0.87 1.1 1.6 1.4 0.094 98 1.9 0.38 1.2 2.2 3.7 6.3 5.7 3.7 1.1 1.5 1.8 2.0 0.067 95 2.7 3.0 2.4 3.5 11 8.8 13 10 2.6 3.0 2.6 3.5 0.067 90 6.3 4.9 4.0 5.8 17 18 28 19 7.8 5.7 4.0 7.0 0.021 85 7.3 6.7 5.7 9.0 21 25 40 32 22 11 5.9 9.7 0.018 80 8.6 9.0 8.0 13 27 34 55 49 31 14 7.7 13 -0.016 75 9.6 11 9.5 15 40 43 67 63 39 17 8.9 17 -0.014 70 11 14 13 22 45 53 76 77 45 19 10 22 -0.009 65 12 18 17 29 50 59 86 95 51 22 11 27 -0.039 60 14 22 21 35 53 67 98 115 56 25 13 34 -0.039 55 18 26 25 39 58 76 112 135 61 27 14 39 -0.062 50 21 32 29 43 63 87 131 146 68 30 16 46 -0.057 45 23 36 34 50 71 101 151 160 75 33 18 53 -0.053 40 27 39 37 53 80 117 168 174 85 38 21 61 -0.032 35 33 43 40 58 94 139 189 195 93 44 28 71 -0.011 30 39 48 44 62 110 161 216 218 104 52 36 86 0.005 25 44 53 49 72 139 185 242 249 116 63 42 105 0.041 20 72 62 55 82 177 212 283 290 131 75 51 132 0.051 15 112 74 64 100 220 248 336 377 158 98 62 171 0.069 10 144 96 74 131 306 318 407 526 205 132 89 232 0.097 5 205 130 94 228 583 433 547 808 396 287 236 377 0.140 2 348 184 122 594 956 847 1,060 1,410 810 501 445 686 0.159

1 476 250 167 753 1,490 1,160 2,040 1,960 1,120 927 563 1,050 0.140

9 05451700 Annual exceedance probability of high discharges, based on 1984–2013 period of record (30 years) Recur- Maximum average discharge (ft3/s) for Annual rence indicated number of consecutive days exceedance interval probability (years) 1 3 7 15 30 0.990 1.01 272 189 127 75 47 0.950 1.05 441 293 194 123 85 0.900 1.11 573 374 247 162 115 0.800 1.25 791 508 333 227 166 0.500 2 1,480 934 616 436 321 0.200 5 2,830 1,780 1,200 853 598 0.100 10 3,990 2,540 1,740 1,220 815 0.040 25 5,790 3,750 2,620 1,790 1,120 0.020 50 7,390 4,850 3,450 2,300 1,370 0.010 100 9,220 6,150 4,450 2,890 1,630 0.005 200 11,300 7,660 5,640 3,570 1,910 0.002 500 14,500 10,000 7,570 4,610 2,300 0.22 Kentau statistic 0.264 0.228 1 0.186 0.232 0.09 P-value 0.042 0.080 0 0.154 0.074

05451700 Annual nonexceedance probability of low discharges, based on April 1983 to March 2013 period of record (30 years) Annual Recur- nonexceed rence Minimum average discharge (ft3/s) for indicated number of consecutive days -ance interval probability (years) 1 3 7 14 30 60 90 120 183 0.01 100 0.01 0.07 0.15 0.28 0.36 0.77 1.2 1.4 2.1 0.02 50 0.04 0.15 0.29 0.50 0.64 1.2 1.8 2.1 2.9 0.05 20 0.20 0.45 0.71 1.1 1.4 2.2 3.1 3.6 4.8 0.10 10 0.68 1.1 1.5 2.1 2.6 3.7 4.9 5.6 7.3 0.20 5 2.2 2.5 3.2 4.1 5.0 6.4 8.1 9.4 12 0.50 2 10 10 10 12 14 16 20 23 29 0.80 1.25 20 21 22 24 28 35 42 49 65 0.90 1.11 24 28 30 32 37 48 60 70 97 0.96 1.04 26 34 38 41 47 65 84 99 146 0.98 1.02 26 37 42 46 53 77 103 122 187 0.99 1.01 26 39 46 50 57 89 122 146 233 Kentau statistic 0.055 0.062 0.071 0.062 0.062 0.007 -0.044 -0.021 -0.067 P-value 0.681 0.643 0.592 0.643 0.643 0.972 0.748 0.887 0.617

05451700 Annual nonexceedance probability of seasonal low discharges, based on October 1983 to September 2013 period of record (30 years) Annual Recur- Minimum average discharge (cubic feet per second) nonexceed- rence for indicated number of consecutive days ance interval probability (years) 1 7 14 30 1 7 14 30 January-February-March April-May-June 0.01 100 0.01 0.17 0.38 0.87 1.1 1.5 2.2 2.6 0.02 50 0.05 0.36 0.71 1.4 2.0 2.6 3.5 4.4 0.05 20 0.27 1.0 1.7 2.8 4.5 5.5 7.0 8.9 0.10 10 1.0 2.2 3.3 4.8 8.4 9.9 12 16 0.20 5 3.5 5.0 6.7 8.8 16 19 22 29 0.50 2 17 17 20 23 44 48 55 79 0.80 1.25 33 39 42 48 82 93 111 166 0.90 1.11 38 52 56 64 103 119 147 226 0.96 1.04 40 65 70 83 121 146 187 295 0.98 1.02 41 72 78 96 130 161 213 341 0.99 1.01 41 77 84 107 137 173 234 381 Kentau statistic -0.152 -0.122 -0.097 -0.094 0.078 0.055 0.071 0.163 P-value 0.246 0.354 0.464 0.475 0.556 0.682 0.592 0.212 July-August-September October-November-December 0.01 100 0.58 0.72 0.87 1.5 0.24 0.28 0.32 0.62 0.02 50 0.82 1.0 1.2 1.9 0.44 0.53 0.60 1.0 0.05 20 1.4 1.6 1.9 2.9 1.0 1.3 1.4 2.1 0.10 10 2.1 2.5 2.9 4.1 2.0 2.5 2.8 3.8 0.20 5 3.6 4.2 4.9 6.4 4.0 5.0 5.9 7.3 0.50 2 9.9 11 13 16 12 15 18 20 0.80 1.25 27 30 35 42 28 32 38 45 0.90 1.11 44 50 58 72 39 42 50 63 0.96 1.04 75 86 99 130 51 53 62 85 0.98 1.02 105 122 141 193 59 59 69 100 0.99 1.01 142 167 194 279 65 63 74 113 Kentau statistic 0.041 0.053 0.057 0.039 -0.014 -0.048 -0.053 -0.099 P-value 0.762 0.695 0.669 0.775 0.929 0.721 0.695 0.454