DWR_2668862

• Title: STREAM FLOW DATA FOR COLORADO
• Year: 2006
• Document Type - Publications and Reports: Streamflow Report

23
PLATTE RIVER BASIN

06709610 SOUTH PLATTE RIVER BELOW CHATFIELD RESERVOIR, CO

LOCATION.--Lat 39°33'26", long 105°03'27", SE¼, sec. 1, T.6 S., R.69 W., Jefferson County, Hydrologic Unit
10190002.

DRAINAGE AREA AND PERIOD OF RECORD.--3,018 mi²; Jan. 1, 1985 to present.

GAGE.--A Stevens A-70 graphic water stage recorder and satellite monitoring DCP and shaft encoder installed in a
formed concrete well and shelter. A new high data rate DCP was installed in 2006 at the gage location
versus the previous location about 2000 ft. away in the control tower for the outlet gates. The DCP is
owned and maintained by the DWR. An electric drop tape is used for referencing. There is no outside
reference. The recorder shelf was replaced in March, 2006 and the elevation was changed for the electric
tape. On September 14, holes were drilled in the floor so that the encoder could be put on its own
float. (The encoder had always been connected to the chart recorder with a ladder chain.)

REMARKS.--The primary record is hourly satellite data with chart back up. Daily max and min values agreed with
the corrected chart values to within +-0.02 foot. The record is complete and reliable, except for the
following period: the linkage between the chart and encoder got kinked and/or the float tape stuck on
March 24-27, 2006, such that the recorders did not follow the change in stage/release. However, the time
of the gate change was known and the release was constant—so the gage height could be estimated without
loss of accuracy. The record is good. Station maintained and record developed by Jana Ash.

RATING TABLE.--PLACHACO03 used from 01-OCT-2005 TO 30-SEPT-2006

DISCHARGE, IN CFS, WATER YEAR OCTOBER 2005 TO SEPTEMBER 2006
MEAN VALUES

DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

1 52 .28 .42 .51 19 .09 22 35 274 212 50 188
2 52 15 .33 .50 25 .09 22 49 319 137 69 185
3 35 65 .28 .49 30 .09 17 36 328 122 151 185
4 10 61 .25 .47 30 .09 11 10 276 75 198 184
5 10 23 3.4 .42 30 .09 11 10 223 26 188 91
6 10 23 8.8 .27 30 .11 11 10 205 109 188 19
7 9.3 23 7.8 .05 30 .11 8.8 10 261 252 281 32
8 7.8 36 5.2 .03 30 .12 5.8 23 263 320 376 22
9 7.8 50 5.0 .03 30 .11 4.8 39 183 534 373 22
10 7.8 30 5.0 .31 22 4.9 12 39 152 767 334 22
11 7.8 12 4.7 .62 11 11 21 31 102 941 297 110
12 7.8 12 4.7 .54 11 11 56 16 28 741 264 187
13 6.9 12 4.3 .51 11 11 74 12 11 620 217 110
14 50 12 14 .46 11 11 45 12 24 497 268 69
15 96 12 28 .42 11 11 30 9.1 90 227 278 45
16 96 12 17 .42 9.4 10 29 18 81 193 139 21
17 66 65 7.4 .40 7.8 10 78 48 44 172 124 21
18 32 118 7.4 .37 7.9 10 135 87 141 48 212 21
19 32 75 8.1 .34 7.9 10 97 160 171 92 212 25
20 32 75 8.5 .31 7.8 27 48 200 64 176 212 31
21 32 86 8.5 .21 7.8 47 37 200 .35 257 212 79
22 32 102 5.0 .20 7.8 47 21 322 .28 350 212 125
23 33 101 3.9 .13 3.4 48 21 464 4.5 378 212 124
24 22 101 7.1 .13 .11 64 13 460 22 376 212 124
25 4.7 100 7.1 .13 .11 80 .16 311 40 287 173 124
26 2.7 100 6.8 .12 .09 80 2.7 244 25 280 137 124
27 .25 101 6.8 .12 .09 80 6.2 284 5.6 402 232 122
28 .25 100 6.8 .11 .09 45 14 260 91 373 320 120
29 .27 78 6.8 .11 --- 11 26 233 235 272 320 120
30 .25 25 4.2 8.4 --- 22 26 230 287 215 272 120
31 .25 --- .48 19 --- 22 --- 229 --- 102 199 ---

TOTAL 755.87 1625.28 204.06 36.13 391.29 673.80 905.46 4091.1 3950.73 9553 6932 2772
MEAN 24.4 54.2 6.58 1.17 14.0 21.7 30.2 132 132 308 224 92.4
AC-FT 1500 3220 405 72 776 1340 1800 8110 7840 18950 13750 5500
MAX 96 118 28 19 30 80 135 464 328 941 376 188
MIN .25 .28 .25 .03 .09 .09 .16 9.1 .28 26 50 19

CAL YR 2005 TOTAL 42017.84 MEAN 115 MAX 895 MIN .01 AC-FT 83340
WTR YR 2006 TOTAL 31890.72 MEAN 87.4 MAX 941 MIN .03 AC-FT 63260

MAX DISCH: 1010 CFS AT 09:30 ON Jul. 11, 2006 GH 3.93 FT. SHIFT 0.08 FT.
MAX GH: 3.93 FT. AT 09:30 ON Jul. 11, 2006

FOR MORE COMPLETE OR DETAILED INFORMATION SEE DAILY OR MONTHLY RECORD.