St. Croix River level climbs from Mississippi River backwash
By ERIK SANDIN – Stillwater Gazette
What Mother Nature takes away, she sometimes gives back in a big way.
Area rivers including the St. Croix, are rising as the result of runoff from frequent mid-spring rains in the Mississippi River watershed after an extended dry period, according to the National Weather Service.
Washington and Dakota counties in Minnesota and Pierce County, Wis., are under a flood warning at Lock and Dam No. 2 until further notice due to rising water on the Mississippi River at Hastings, according to the NWS.
The rising Mississippi River is being felt in communities along the St. Croix River, which is rising due to backwash from the Mississippi, according to Diane Cooper, NWS hydrologist.
"That’s what we’re looking at. A key point for Stillwater is that the (high water) is because of backwater from the Mississippi," Cooper said.
An NWS statement notes that many areas in the Mississippi River watershed received 1 to 2 inches of rain last weekend. The Mississippi at Lock and Dam No. 2 was at 12.6 feet early Tuesday morning. Flood stage there is 15 feet. The NWS hydrology forecast calls for the Mississippi to hit flood stage in Hastings Friday and crest at a forecast 16.3 feet Sunday afternoon.
The agency adds that minor flooding is expected.
What is happening in Hastings will affect the St. Croix River over the next several days, Cooper said. At 9:15 a.m. today, the St. Croix was at 84.31 feet in Stillwater, less than three feet below the river’s 87-foot minor flood stage.
Cooper said the forecast calls for the St. Croix to crest at slightly more than 86 feet late Friday or early Saturday and maintain that level through the weekend before slowing receding next week.
What affect the rising lower St. Croix has on communities along the river is hard to predict, Cooper said. She notes that some areas along the river might not be affected due to lack of development, while other areas could experience some problems.
"Each community is specific to impacts," she said.
The reason area rivers are rising is easy to answer, according to Cooper.
"We’ve had a lot of precipitation over the last week," she said.
Last week’s rains were added to an already wet May that followed a relatively dry period from mid-August through the fall and winter into this spring, Cooper said.
"Basically, the spigot got turned on in April," she said. "We have gone from one extreme to another."
Although the long-range climate outlook gives no indication of future precipitation, Cooper said this week’s outlook calls for several days of dry weather before another chance of thunderstorms moves into the St. Croix Valley this weekend.
"We have a dry stretch of weather through the week," she said.
Highs today through Friday are expected in the low to mid-60s with sunny to partly cloudy skies. Overnight lows will be cool, falling to the middle to upper-40s. Warmer air is forecast for Saturday and Sunday with a high Saturday near 72 and rising to 78 Sunday. The next chance of showers and thunderstorms in the Valley is Sunday night and Monday.