DWR_2668849

• Title: STREAM FLOW DATA FOR COLORADO
• Year: 2005
• Document Type - Publications and Reports: Streamflow Report

41
PLATTE RIVER BASIN

06724000 ST. VRAIN CREEK AT LYONS, CO

LOCATION.--Lat 40°13'05", long 105°15'34", in NW¼NW¼ sec. 20, T.3 N,, R.70 W., Boulder County, Hydrologic Unit
10190005, on left bank 75 ft southwest of U.S. Highway 36 (State Highways 7 and 66) at southeast edge of
Lyons, 400 ft upstream from St. Vrain Supply Canal, and 0.4 mi downstream from confluence of North and
South St. Vrain Creeks.

DRAINAGE AREA AND PERIOD OF RECORD.--212 mi². Aug. 1887 to Sep. 1891, June 1895 to current year. Monthly only
data for some periods. Water quality data available from Oct. 1977 to Feb. 1981. On March 23, 2003, the
gage was moved approximately 0.2 mi upstream. In the new location, the gage is above the Supply Ditch
diversion, whereas the old location was below this diversion.

GAGE.--Graphic water stage recorder and satellite monitoring DCP and shaft encoder in a wooden shelter with a
stilling well. Primary reference is an electric drop tape down from an RP with the outside chain gage as
backup. The DCP log is the primary record with the graphic chart as back-up.

REMARKS.--Primary record is hourly data taken from satellite monitoring using the new well with chart back up
from the well. The record is complete and reliable except for the following periods: November 30, 2004-
February 28, 2005 when the station was closed was closed for the winter; and June 27-28, 2005 when the
DCP failed and chart backup was not available due to the pen not inking. Ice hours were observed and
corrected on November 25, 28, and 29 without loss of accuracy. The record is good, except for November
30, 2004-February 28, 2005; and June 27-28, 2005, which were estimated and poor. Station maintained by
Merlin Friedrichsen and record developed by Div. 1 Hydrographic Staff.

RATING TABLE.--SVCLYOCO24 USED FROM 01-OCT-2004 TO 30-SEP-2005

DISCHARGE, IN CFS, WATER YEAR OCTOBER 2004 TO SEPTEMBER 2005
MEAN VALUES

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

1 75 29 21 13 24 17 21 140 434 356 133 47
2 69 21 23 13 24 19 25 139 490 358 141 45
3 65 26 23 13 24 15 28 150 631 355 194 40
4 63 32 23 13 24 16 29 178 576 365 212 41
5 59 32 22 13 23 16 38 211 480 331 234 41
6 73 31 22 13 23 18 36 225 437 284 185 38
7 92 26 22 13 23 17 39 217 450 268 155 38
8 76 26 22 14 23 18 51 197 445 289 129 36
9 69 25 22 14 23 18 50 169 450 287 124 37
10 62 32 22 14 23 19 52 156 476 287 134 37
11 57 33 22 14 23 17 51 254 439 275 142 34
12 56 30 22 14 22 18 50 386 412 261 147 31
13 65 30 21 15 22 21 54 360 372 265 136 33
14 66 30 21 15 22 18 58 323 325 272 139 35
15 58 25 21 15 22 19 65 306 364 303 121 35
16 58 21 21 15 22 22 61 308 458 279 110 31
17 48 23 20 16 22 22 63 310 513 261 102 28
18 45 24 20 16 21 21 67 286 556 255 92 27
19 42 24 20 16 21 20 77 306 575 235 87 23
20 39 25 19 16 21 22 111 410 592 214 82 19
21 41 22 19 17 21 22 125 501 573 201 79 19
22 43 22 18 17 20 22 115 575 581 193 77 22
23 42 23 18 18 19 21 117 614 609 184 76 22
24 37 22 17 19 18 21 125 587 614 197 70 22
25 30 24 17 19 18 21 132 540 591 246 66 20
26 31 24 16 20 17 21 130 534 523 262 68 20
27 33 21 16 21 16 22 131 507 505 226 60 19
28 31 23 15 21 17 24 140 470 457 180 59 25
29 41 21 15 22 --- 25 139 434 424 154 56 25
30 24 20 14 23 --- 22 143 440 390 141 55 22
31 25 --- 14 23 --- 23 --- 489 --- 134 48 ---

TOTAL 1615 767 608 505 598 617 2323 10722 14742 7918 3513 912
MEAN 52 26 20 16 21 20 77 346 491 255 113 30
AC-FT 3200 1520 1210 1000 1190 1220 4610 21270 29240 15710 6970 1810
MAX 92 33 23 23 24 25 143 614 631 365 234 47
MIN 24 20 14 13 16 15 21 139 325 134 48 19

WTR YR 2005 TOTAL 44840 MEAN 123 MAX 631 MIN 13 AC-FT 88940

MAX DISCH: 1160 CFS AT 15:00 ON Jun. 3, 2005 GH 3.75 FT. SHIFT -0.04 FT.
MAX GH: 3.75 FT. AT 15:00 ON Jun. 3, 2005