The National Weather Service is predicting another shot of rain for Southcentral Alaska through Wednesday, due to low pressure moving in from the Bering Sea coast.
Heavy rains over the weekend have swollen the Matanuska River and other Matanuska Valley waterways, although no flood danger is expected at this time.
U.S. Geological Survey hydrologist Steve Frenzell says larger rivers, like the Matanuska and Susitna, are not likely to flood due to a few days of rain because of the size of their watersheds, so they can store more water than a small creek.
Water levels are high on the Matanuska and Susitna, but both rivers are far from flood stage. The Little Susitna River, however, on Tuesday broke its 1962 record for the amount of water discharged per second. Tuesday’s gauge is 1,420 cubit feet per second.
Water level data is gathered by instruments that feed data to a satellite every 15 minutes. NOAA’s river forecast arm uses this data to determine when to issue flood watches.
“So, the latest is that most of the smaller streams that are along the Parks Highway that are on the western-draining Talkeetna Mountains, those have reached the bankfull levels throughout the day [Tuesday] and they have either turned around or they will be turning over very shortly to begin receding,” Selina Van Bruekelen, a hydrologist in Anchorage, said.
The Matanuska River at Palmer surpassed 8 feet early Tuesday morning, compared with 7 feet on Sunday. The Susitna River at Sunshine reached 19.5 feet Tuesday, compared with 17 feet on the first of the month.
Heavy storms in September of last year caused widespread flooding within the Matanuska-Susitna Borough.
The area received disaster designation, and later received federal assistance to repair damages to Borough infrastructure and to private property.