Stratton Operations Update
Fox River Status Update
August 4, 2015
The Chain is currently at summer pool, but inflows are dropping. The river below Stratton Dam is dropping with inflows. As stated in the National Weather Service public information statement below the last half of July has been dry for northeast Illinois. The percentage of normal rainfall graph below shows that portions of the Fox River watershed were deficient in their rainfall by up to 25% of normal during July.
National Weather Service statement:
PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
1003 PM CDT SAT AUG 1 2015
...PRONOUNCED DRY STRETCH TO END JULY...
AFTER FREQUENT RAINFALL FROM MID-SPRING THROUGH THE FIRST HALF OF
METEOROLOGICAL SUMMER...THE LATTER HALF OF JULY SAW LITTLE TO NO
RAINFALL IN SOME COMMUNITIES OF NORTHERN ILLINOIS AND NORTHWEST
OFFICIALLY AT CHICAGO OHARE...ONLY A TRACE OF RAINFALL WAS
OBSERVED FROM JULY 19-31. THIS 13 DAY STRETCH OF NO MEASURABLE
PRECIPITATION WAS THE SECOND LONGEST OF 2015 AND THE LONGEST SINCE
MARCH 4-21. THIS COMES AFTER 24 DAYS WITH MEASURABLE RAINFALL BETWEEN
JUNE 7 AND JULY 18...IN OTHER WORDS ON 57 PERCENT OF THE DAYS!
AT ROCKFORD...THERE WAS ONLY 0.04 INCHES OF RAIN BETWEEN JULY
17-31. THIS 15 DAY STRETCH WAS THE DRIEST SINCE MARCH 4-22 WHEN
ONLY A TRACE WAS OBSERVED.
The National Weather Service (NWS) is predicting minimal rain (¼”- ½” total) for the next 7 days. The inflows into the system are expected to continue to fall.
The Algonquin Dam is being operated to hold back the maximum amount of water possible. The gates at Stratton Dam are being operated to balance the flows coming into the system and the flows going out of the system. Our operations guide calls low flow 390 cfs coming into the lakes. Currently the Fox River at New Munster is 170 cfs and Nippersink Creek at Spring Grove is 100 cfs. This gives us an inflow into the lake of approximately 270 cfs which puts us squarely into low flow operations. Our operation guide would allow us to go to a minimum release of 182 cfs today, but since the lakes are at summer pool already there is no need to store extra water. The lakes also have minimal storage so opening the gates to allow the lower river to come up would only increase flows in the lower river for a few days and then it would be right back to where it is now, so that is not a viable option. Assuming there is minimal precipitation, as the flows continue to drop we will continue to operate the gates to balance the incoming and outgoing flows in the system.
Brad Winters, P.E., CFM
IDNR Office of Water Resources