Water and Environmental Research Center

Site Details

15862500 UBLUTUOCH R 13.7 MI AB MOUTH NR NUIQSUT AK

Most recent revision: 2/16/2012
Revised by: D.A. Vas (UAF)

SPECIAL NOTE.--Prepared by: J.D. Eash (USGS) 2-15-2006 Updated by: J.D. Eash (USGS) 12-06-2008

LOCATION.--Lat 70°14'33.56", long 151°17'41.81" referenced to North American Datum of 1983, in SW 1/4 SE 1/4 SE 1/4 sec.2, T.10 N., R.3 E., North Slope Borough, AK, Hydrologic Unit 19060205, 13.7 mi upstream from mouth and 7 mi northwest of Nuiqsut.

ROAD LOG.--Station is reached by BLM chartered helicopters during summer months and chartered fixed wing aircraft (Piper Super Cub during early October and Cessna 185 or smaller) during winter months.

SITE HAZARD ANALYSIS.--Extreme caution should be exercised during break-up flooding. Ice becomes anchored to the bed during the winter. Warmer spring temperatures produce flow over the top of the ice for several weeks, until the ice releases from the bed and violently rises to the surface. Personal observation is necessary to know when the river is free of ice.
Dry suits should be worn during breakup measurements due to the possibility of the boat capsizing, cold temperatures during June on the North Slope, and the remote location of the gage.
See list of generic JHA's, located in the field folder.

DRAINAGE AREA.--Undetermined.

ESTABLISHMENT AND HISTORY.--Established 2002 by R.T. Kemnitz of the Bureau of Land Management (BLM). Maintained from 2002 to 2006 by BLM. The USGS assumed responsibility of this station on May 29, 2007 at which time a standard USGS gage structure and equipment were installed by J.D. Eash and M.R. Carr. The BLM reassumed responsibility on September 30, 2009 and its running this gauge together with UAF personal.

GAGE.--A Sutron 8210 with GOES Satlink transmitter coupled to two Pressure Systems KPSI pressure transducers with water temperature probes housed in a 2 ft. x 3 ft. aluminum shelter. The gage is located on the right bank. Power is provided by three 100 amp/hour 12v batteries charged by a solar panel. DCP antenna and solar panel are mounted to a 2 inch pipe bolted to the top of the gage house. A Thermex air temperature probe is also coupled to the Sutron DCP. Water surface reference is usually by levels due to the constant movement of the RP's. The elevation of the instrument shelf within the gage is approximately 22.5 ft., mean sea level (MSL) (July 15, 2007).
The pressure transducers, as well as their wiring are each connected to a 1" steel cable and anchored to the stream bank by rebar. One transducer is set deep to collect low flows, while the second transducer is set shallow to collect high flows. The lower transducer is often torn free from the bank during breakup. The wiring and cables are buried along the bank and are only exposed at low flows. Neither pressure transducer is removed prior to freeze up in an attempt to collect the most possible data. Damage or loss of the lower pressure transducer by ice is possible during break-up and a spare transducer should be stored on site or carried during the post break-up site visits. The transducer elevations are: Lower= 4.23 ft., MSL (July 11, 2008). Upper= 8.64 ft., MSL (July 14, 2007). A standard 4 ft. USGS crest-stage gage is located adjacent to the gage with a pin elevation of 16.38 ft., MSL (May 30, 2008).
There are two staff plates located on the left bank directly across the stream from the gage. These staff plates are used by private consulting firms associated with Conoco Phillips. The correction to the lower of the two outside staffs is +16.00 ft. (July 14, 2007).

CONTROL.--The channel's bed materials are composed primarily of fine to coarse gravels. Stream banks are heavily vegetated with shrubs and grasses. Banks are relatively high but are subject to overflow during break-up when ice jams, flow over snow, and extremely high flows are common. Control is the channel, stream bank vegetation, and overbank vegetation at high flows. The low to medium flow control is a gravel riffle approximately 100 ft. downstream of the gage. The stream is confined to one channel at all stages. Control will be snow and ice covered for about seven to eight months during the winter. The entire channel will become buried in snow up to 13 ft. deep during most winters. The channel is fairly straight for about 200 ft. upstream and about 200 ft. downstream of the gage.

DISCHARGE MEASUREMENTS.--Open-water measurements can be made by boat or by wading, depending on river conditions. Boat measurements can be made at the gage. Wading measurements can be made anywhere in the vicinity of the gage at medium to low flows. Extreme low flow measurements can be made on a small riffles upstream or downstream of the gage. ADCP measurements should be accompanied with GPS reference due to the possibility of moving bed conditions at most stages. Winter flows will typically be too low for ice measurements.

FLOODS.--To be determined.

POINT OF ZERO FLOW.--Approximately 4.3 ft. (7/14/2007)

WINTER FLOW.--Heavy ice effect during winter. Periods of zero flow are expected during most winter months.

ACCURACY.--Discharge measurements and gage-height record will be fair to poor during open water periods due to lack of rating definition. Ice affected periods will be poor.