07128500 PURGATOIRE RIVER NEAR LAS ANIMAS, CO
LOCATION.--Lat 38°02'02", long 103°12'00", in NE14SW14 sec.23, T.23 S., R.52 W., Bent County, Hydrologic Unit 11020010, on left bank at downstream side of bridge on State Highway 101, 2.3 mi southeast of courthouse in Las Animas, and 4.5 mi upstream from mouth. Prior to July 17, 2002, at site on right bank.
DRAINAGE AREA.--3,318 mi2, of which 11.8 mi2 is noncontributing.
PERIOD OF RECORD.--May to September 1889, July to October 1909 (gage heights and discharge measurements only), January 1922 to September 1931, July 1948 to current year. Monthly discharge only for some periods, published in WSP 1311. Published as Purgatoire Creek at Las Animas in 1889 and as Purgatory River near Las Animas in 1909. Statistical summary computed for 1978 to current year, subsequent to completion of Trinidad Reservoir. Daily record for water temperature and specific conductance available, December 1985 to September 1996. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=07128500
REVISED RECORDS.--WSP 1241: 1927(M); WDR CO-01-1: Drainage area.
GAGE.--Water-stage recorder with satellite telemetry. Datum of gage is 3,878.04 ft above NGVD of 1929. See WSP 1731 for history of changes prior to Oct. 1, 1955. Oct. 1, 1955 to July 11, 1966, at datum 6.00 ft higher. Supplementary water-stage recorder at site 1.6 mi downstream at different datum July 12 to Nov. 17, 1966. Nov. 18, 1966 to
May 4, 1982, at datum 3.1 ft higher. May 5, 1982 to July 17, 2002, at site on right bank at same datum.
REMARKS.--Records good except for estimated daily discharges, which are poor. Natural flow of stream affected by storage reservoirs, diversions for irrigation and municipal use, ground-water withdrawals, return flows from irrigated areas, and flows from sewage-treatment plants. Flows regulated to some extent by Trinidad Lake (station 07124400) about 141 mi upstream since January 1975. Several measurements of specific conductance and water temperature were obtained and are published in the "Supplemental Water-Quality Data For Gaging Stations" section of this report.
EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of Oct. 1, 1904, is the greatest since at least 1860, discharge unknown.
a Average discharge for 37 years (water years 1923-31, 1949-76), 116 ft3/s; 84,040 acre-ft/yr, prior to completion of Trinidad Reservoir.
d From rating curve extended above 4,460 ft3/s; maximum discharge for period of record, 70,000 ft3/s, May 20, 1955, from rating curve extended above
38,000 ft3/s, gage height, 15.00 ft, datum then in use.