Millstone River at Blackwells Mills, Somerset County NJ (BKWN4)
Gage Location: Somerset County, New Jersey	Site Location: Somerset County, New Jersey
Latitude: 40.475	Longitude: -74.576	Elevation: 26.97 ft. MSL	Drainage Area: 258 Sq. Mi.
Minor Stage: 9 ft.	Moderate Stage: 10 ft.	Major Stage: 15 ft.
First Flood: 1924-04-07	Last Flood: 2011-12-08 Crest: 10.79 ft.	Datum change: 1928-08-17	Number of Floods: 144

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Month Number of Floods After Datum Number of Floods Total Cumulative Total After Datum Cumulative Total January 16 16 16 16 February 9 10 25 26 March 29 29 54 55 April 15 16 69 71 May 4 4 73 75 June 5 5 78 80 July 9 10 87 90 August 9 9 96 99 September 9 10 105 109 October 6 7 111 116 November 8 8 119 124 December 20 20 139 144 Seasonal Totals Winter (Dec-Jan-Feb) 46 Spring (Mar-Apr-May) 49 Summer (Jun-Jul-Aug) 24 Fall (Sep-Oct-Nov) 25

Codes and description

C1|Crest information looks unreliable and incomplete and not used in frequency calculations. Some of the floods are based on current flood stage and nearby gage information.
C2|Crest information looks reliable despite potential problems. This data was used in frequency calculations.
C3|Crest height estimated by the USGS.
C4|Crest height is from the National Weather Service.
C5|Crest height affected by backwater.
C6|Crest occurred at a previous flood stage that is lower than the current flood stage. The crests below the new flood stage are not used in flood frequency calculations.
C7|Crest from USGS yearly peak and/or date is different than the crest we provide. In many cases MARFC uses crest based on backwater or ice effects.
C8|Crest month or day of occurrence has been estimated by The Middle Atlantic River Forecast Center usually based on nearby gage information.
C9|Crest date (day) in the month is unknown.
F1|Flow is an estimate.
F2|Flow affected by regulation or diversion and in some cases to an unknown degree.
F3|Flow effected by snow-melt, ice jam or debris jam break up.
F4|Flow affected by dam failure.
F5|Flow - All or part of the record affected by urbanization, mining, agricultural changes, channelization or other factors.
G1|Gage height at a different site and/or datum.
G2|Gage is not an official USGS gage with crests provided by the NWS. Crest information looks unreliable and incomplete and not used in flood frequency calculations.
G3|Gage datum changed during this year.
none,No code; Good Data

Updated: 08:09 AM Feb 08, 2013