Public Information Statement
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

000
NOUS43 KLOT 141432
PNSLOT

SERVICE CHANGE NOTICE
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
930 AM CDT TUE OCT 14 2014

TO:     FAMILY OF SERVICES/FOS/SUBSCRIBERS...NOAA WEATHER WIRE
        SERVICE/NWWS/SUBSCRIBERS...EMERGENCY MANAGERS WEATHER
        INFORMATION NETWORK/EMWIN/SUBSCRIBERS...NOAAPORT
        SUBSCRIBERS...OTHER NATIONAL WEATHER SERVICE CUSTOMERS
        AND PARTNERS...AND NWS EMPLOYEES.

FROM:   WILLIAM MORRIS
        SERVICE HYDROLOGIST
        NWS CHICAGO/ROMEOVILLE IL

SUBJECT:CHANGES TO GAGE ZERO DATUM...FLOOD STAGE...AND IMPACT LEVELS
ON THE DES PLAINES RIVER AT THE DES PLAINES IL RIVER GAGE.

EFFECTIVE NOVEMBER 14 2014...THE GAGE ZERO DATUM AT THE U.S.
GEOLOGICAL SURVEY(USGS) STREAMGAGE ON THE DES PLAINES RIVER NEAR DES
PLAINES ILLINOIS WILL BE CHANGED BY 10.0 FEET. GAGE ZERO DATUM IS A
HORIZONTAL SURFACE USED AS THE ZERO POINT FOR MEASUREMENT OF RIVER
STAGE...ALSO REFERRED TO AS GAGE HEIGHT.

BACKGROUND
THE PHYSICAL LOCATION OF THE USGS STREAMGAGE AT DES PLAINES IL HAS
CHANGED. THE GAGE IS NOW LOCATED AT THE EUCLID AVENUE/WEST LAKE
AVENUE BRIDGE...APPROXIMATELY 0.4 MILE UPSTREAM FROM THE PREVIOUS
LOCATION. THE MOVE WAS NECESSITATED BY THE REMOVAL OF DAM 2 BY THE
ILLINOIS DEPARTMENT OF NATURAL RESOURCES BEGINNING ON MAY 28 2014.
AT THE CURRENT DATUM...LOW FLOWS ARE RESULTING IN THE REPORTING OF
NEGATIVE STAGES.

THE USGS WILL BE ADJUSTING THE ZERO DATUM USED TO REFERENCE GAGE
HEIGHTS...FLOOD STAGE...AND IMPACT LEVELS. THE ZERO DATUM WILL BE
CHANGED FROM 626.31 TO 616.31 FEET TO AVOID NEGATIVE READINGS.

IMPACTS TO USERS
ALL EXISTING FLOOD AND IMPACT STAGES WILL BE INCREASED BY 10 FEET.
NEW FLOOD THRESHOLDS WILL BE AS FOLLOWS:

     FLOOD STAGE        OLD 5.0 FEET     NEW 15.0 FEET
     MODERATE FLOOD     OLD 8.0 FEET     NEW 18.0 FEET
     MAJOR FLOOD        OLD 9.0 FEET     NEW 19.0 FEET

IN ADDITION...IT WAS DETERMINED THAT SOME MINOR IMPACTS BEGIN AT
LEVELS SLIGHTLY BELOW THE EXISTING ACTION STAGE. THUS THE NEW ACTION
STAGE WILL BE ADJUSTED TO 13.5 FEET.

THESE CHANGES HAVE BEEN COORDINATED WITH THE U.S. GEOLOGICAL
SURVEY...AND ILLINOIS DEPARTMENT OF NATURAL RESOURCES.

RIVER FORECAST AND FLOOD WARNING INFORMATION IS AVAILABLE FROM
THE NOAA NWS ADVANCED HYDROLOGIC PREDICTION SERVICE PAGE BY CLICKING
ON THE RIVERS AND LAKES LINK ON THE NWS CHICAGO WEB SITE AT:
WEATHER.GOV/CHICAGO

RIVER STAGE DATA IS ALSO AVAILABLE FROM THE U.S. GEOLOGICAL SURVEY
AT: USGS.GOV/WATER

MORE INFORMATION ON THE U.S. GEOLOGICAL SURVEY STREAMGAGE PROGRAM
CAN BE FOUND AT: WATER.USGS.GOV/NSIP

RIVER FLOOD INFORMATION IS ALSO BROADCAST ON NOAA WEATHER RADIO.

IF YOU HAVE ANY QUESTIONS PLEASE CONTACT:

WILLIAM MORRIS                             JON HORTNESS
SERVICE HYDROLOGIST                        HYDROLOGIST
NATIONAL WEATHER SERVICE FORECAST OFFICE   US GEOLOGICAL SURVEY
333 W UNIVERSITY DRIVE                     DEKALB IL
ROMEOVILLE IL 60446                        815-752-2036
PHONE: 815-834-0600 X493                   HORTNESS@USGS.GOV
EMAIL: WILLIAM.MORRIS@NOAA.GOV

$$

WDM



































USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.