DWR_2668843 - Laserfiche WebLink

Discharge.-- PLATTE RIVER BASIN TARRYALL CREEK AT BORDEN DITCH Location.-- Drainage and Period of Record.-- Lat. 39º17’13”,Long. 105º41’43”, in the NW ¼ of the NW ¼ of Sec. 8, T. 9 S., R. 74 W., Park County, Hydrologic unit 10190001, on left bank 1800 ft. downstream from Rock Creek, 9 mi. southeast of Jefferson and 1.0 mi. northwest of Bordenville. 230 mi². Apr. 26, 1983 (no previous gage at this site). Operation discontinued by USGS Sept 30, 1997. Taken over by Colorado Division of Water Resources. Sutron SatLink 2 satellite monitoring data collection platform (DCP) with a Sutron 56-0540 shaft encoder (SE) enclosed in a steel box shelter atop a 18 inch corrugated metal pipe (CMP) mounted vertically on the stream bank. The primary gage reference is a drop tape and shelf mounted reference point (RP) with a supplementary outside staff gage. Gage and equipment are owned by City of Aurora and operated by the Colorado Division of Water Resources under contract with the City of Aurora. Equipment.-- Hydrographic Conditions.-- Gage-Height Record.-- Datum Corrections.-- Rating.-- Discharge.-- Special Computations.-- Remarks.-- Recommendations.-- High mountain alluvial plateau mostly devoid of forest. Conditions remain stable with continued light residential development upstream. Discharge affected by irrigation diversions and releases from Jefferson Lake. The record is hourly averages of telemetered 15-minute shaft encoder data. The record is complete and reliable, except as follows: October 22, 2008 to November 3, 2008, when the gage was affected by ice conditions; November 4, 2008 and April 13, 2009, partial day records (shut-down and start-up days) , November 4, 2008 through April 14, 2009, when the station was off for winter and no record is maintained . Instrument calibration was verified by twenty-eight visits made to the gage. One SE adjustment (0.02 ft) was made on May 18, 2009. Levels were run on September 27, 2009. It was not possible to correlate elevations gained to levels run by City of Aurora personnel nor USGS staff when the gage was in their control. Therefore, elevations for reference marks RM 1 and RM 3 were reassigned as follows: RM 1 reassigned from 7.274 to 7.034 feet, and RM3 reassigned from 8.742 to 8.505 feet. RM 2 was not located and abandoned . The control at low to medium flows is a rock riffle downstream composed of gravel and some large boulders. The stream channel is the control for higher stages up to an approximate gage-height of 6.00 ft where the channel is subject to overflow. Rating No. 6 was used all year and is well defined between 18.4 and 247cfs. It is valid for the range of flows experienced this year. Eleven measurements (Nos. 69 - 79) were made, ranging in discharge from 18.8 to 188 cfs. Average daily flow was above the highest measurement of 188 cfs on the following days: May 22-27, June 1-6, 21, 22, 2009. Peak discharge of 308 cfs occurred at 0415 June 2, 2009 at a gage height of 4.15 ft with a shift of 0.00 ft. The peak exceeded measurement No. 73 by 0.65 feet in stage. Shifting control method was used all year. Shifting is caused by the movement of material (sand, silt, rocks, and boulders) across the control and gage pool sections. Frost heave can affect the first measurements of the spring, since the creek thaws before the ground does. Unadjusted shifts ranged from -0.03 to 0.11 feet. Shifts were applied as follows: October 1 through October 21, 2008; Time proration as defined by measurement Nos. 68-69 April 14 through April 30, 2009; Time proration as defined by measurement Nos. 70-71 April 30 through June 2, 2009, (04:15) Stage dependant shifting using variable shift table TARBORCOVST1 which is defined by three measurements (Nos. 71-73) made during the period of use. June 2 through September 31, 2009; Stage dependant shifting using variable shift table TARBORCOVST2 which is defined by eight measurements (Nos. 74-80) made during the period of use. Measurement Nos. 74, 75, 77 and 79 were adjusted to better fit the shift distribution as follows: No. 74 was adjusted -1% from a computed shift of -0.02 feet to a shift of 0.00 feet No. 75 was adjusted 2% from a computed shift of +0.04 feet to a shift of 0.03 feet No. 77 was adjusted -5% from a computed shift of -0.01 feet to a shift of 0.02 feet No. 79 was adjusted 4% from a computed shift of 0.04 feet to a shift of 0.02 feet Discharge for the ice affected period was based on computed record for Oct 22-24, 27-31 and Nov. 1-3. Adjacent computed flows were used for Oct. 25, 26. Gage heights showed a marked temperature effect. The degree of ice effect was not easy to determine. Nov. 1-3 showed the least such effects, had warm temperatures and is likely good record. However, we do not have any observations recorded by Aurora when they closed the gage on Nov.4 and cannot say for sure that ice was not present. So while the period is bracketed by what appear to be reliable numbers, it is still considered to be estimated and poor. This is a partial year record. No discharge record is kept for the winter period (November 4, 2008 through April 14, 2009). The record is rated good, except for October 22—Nov. 3 which is estimated and poor. No estimates were made for the winter period from Nov 4, 2008 through April 14, 2009 as the gage is considered seasonal. Station maintained and record developed by Mike Wild. The supplemental staff gage should be replaced and calibrated to match the station primary reference. Levels must be run next season when soil conditions stabilize after winter freeze and thaw cycles. 2009Water Year