WINTER 2006 BASIN CONDITIONS
February 22, 2006
HUDSON BAY DRAINAGE
Souris River Basin
Both the Canadian and the US portions of the Souris River Basin received less than 50 percent of normal precipitation during the fall of 2005. River flows during the fall period were 25 to 75 percent of normal. The current levels at Rafferty and Alameda Reservoirs located in Saskatchewan are slightly below the desired elevation, and no releases are planned for this coming spring. Lake Darling has 15 to 18 inches of ice, and according to the USGS staff there are many locations on the Souris that are ice free. Current frost depth in the Minot area is 20 inches and 12 to 14 inches in the Rolette area. The basin is nearly snow-free with the exception of the lower portion from Towner to Westhope, ND. The greatest snowpack and water equivalent exists in the Turtle Mountains and areas to the east. Snow water equivalent in this area averages about 2 inches based on NOHRSC flights and model simulated water equivalent.
Red River of the North River Basin
Fall precipitation in the headwater area exceeded 300 percent of normal and averaged 100 to 300 percent of normal over the remainder of the basin. Model simulated soil moisture was above normal in September and October due to summer precipitation. Two major storm systems tracked over the southern portion of the basin in early to mid November. Due to the temperature regime during these events, the precipitation fell as a liquid, liquid snow mix. This resulted in a ground ice layer of 1 to 2 inches, which currently still exists below the snow cover in southeast North Dakota and south of Fargo to the headwater area in Minnesota.
Currently, streamflows over much of the Red River Basin are above normal according to the USGS. Reservoirs are undergoing the winter draw down operation. River ice thickness ranges from 9 to 18 inches which is about a foot less than the normal January thickness. Frost reports indicate little to no frost existed in the basin upstream of Halstad into January. Early February reports show the frost is currently increasing due to the more normal winter temperatures. Modeled simulated snow water equivalent currently ranges from 3 to 4 inches in the headwaters area and 2 to 3 inches over most of the remainder of the basin. The model simulated soil moisture indicates very wet soils over most of the basin.
Orwell Reservoir on the Ottertail River is at the draw down elevation target which is currently in affect and discharging 750 cfs. Additional storage is available if needed. Lake Traverse-White Rock Reservoir is at the draw down target and is not discharging any flow, which is normal through the peak of normal spring runoff. Baldhill Reservoir on the Sheyenne River is also at the currently selected drawdown elevation and discharging about 50 cfs. Additional storage is available if needed.
Devils Lake Basin
The fall precipitation over the basin ranged from 100 to 400 percent of normal. A portion of the fall precipitation total came during an early October storm which resulted in 14 to 20 inches of snow and a water equivalent over 2 inches. Fall inflow was much below normal allowing the lake level to drop three quarters of a foot since early September of 2005. Precipitation since the first of the year is about 50 percent of normal. Modeled snow water equivalent currently ranges from 1 to 3 inches over the basin, and the modeled soil moisture shows the basin close to saturation. Ice thickness is below normal, and currently measured at 12 to 15 inches on Devils Lake. Field observations indicate that only thin and slush ice had formed on Stump Lake.
GREAT LAKES DRAINAGE
Upper Peninsula of Michigan
Fall precipitation totals were 100 to 200 percent above normal over the basin. Fall flows were normal. Lake effect has contributed the greatest snow accumulations along the coastal area and into the eastern Upper Peninsula. Amounts of 4 to 6 inches of snow water equivalent are typical. The interior snow water equivalent conditions are roughly 3 to 4 inches. Frost depths are estimated to be shallow due to the warm winter temperatures.
Menominee River Basin
Last summer the Menominee River Basin only received 50 to 75 percent of normal precipitation, so going into October flows were well below normal. However, precipitation during the fall recharged the soils and baseflow levels to near normal conditions. A recent snow survey indicated 2 to 3 inches of snow water equivalent over the southern end of the basin and 2 to 4 inches in the upper portion of the basin above the two largest reservoirs, Way Dam and Peavy Falls Dam. Way Dam continues it's standard winter draw down, and Peavy Falls Dam will begin it's draw down next month. River levels on the Menominee River near Pembine, WI have been periodically elevated during the last couple months due to changing ice conditions, but has remained below flood stage. The stage record during the past couple weeks seems to indicate that there is a river ice cover downstream of the gage, but no ice jam problems are anticipated at this time. The recent mid February storm contributed to a basin average of about 3 inches of snow.
Northern Lower Michigan Basins
Precipitation totals were 75 to 300 percent above normal over the basin for November and December. River flows were below normal during September and October and near normal the remainder of the fall according to the USGS. Current snow water equivalent is 1 to 2 inches in the southern portion of the basin and 2 to 4 inches in the northern portion of the basin. Frost depths are estimated to be shallow due to the warm winter temperatures. Modeled simulated soil states indicate the top layers to be very wet. Approximately 4 to 11 inches of snow fell over northern lower Michigan during last weeks' snow event.
Grand, Kalamazoo, St. Joseph, Saginaw and White River Basins
Fall soil moisture ranged from dry in eastern portions of the basin to moderate drought levels over the western half according to the U.S. Drought Monitor in November. Fall flows ranged from 10 to 75 percent of normal in September and October to near normal during the rest of the season. However a major storm in early November and a series of smaller storms during the winter months has increased soil moisture conditions significantly. River flow levels are currently above normal according to the USGS. No significant flooding occurred during the winter. Frost depths are being reported as very shallow. Snow fall of 1 to 5 inches was reported as of a result of the storm on February 16th over the Grand River Basin.
Southeastern Michigan Streams
September and October flows were below normal according to the USGS, and near normal to above normal in late fall. Fall precipitation was 100 to 300 percent of normal during November and December which resulted in minor to moderate within bank rises, but no flooding occurred. The simulated model states were affected by the previously mentioned wet episodes and are therefore fairly sensitive to precipitation. Currently, river flows are above normal, in the 70 to 90 percentile range, according to the USGS. Little or no ice has been reported in the rivers. The northern basins had 1 to 6 inches of snow with about a half inch of snow water content. There is little or no snow in the southern basins.
Eastern Wisconsin Streams
Early fall river flows were 50 to 90 percent of normal while November flows were 150 percent of normal. Rivers were generally at baseflow levels before entering freeze up. Some rivers are ice affected at this time. The Root River is ice free and the flow is currently at the 50 percentile according to the USGS. There has been no flooding for several months and only brief rises occurred on the Root River in the late fall and early winter. There is about 20 to 25 inches of snow on the ground in the far northern basins, of which up to 10 inches fell during the recent mid February snow event. Snow water equivalents are around 3 inches in the far north in the Langlade, Shawano, Morgan, and Gillett basins, but are generally less than 1 inch elsewhere. Frost depths vary from 5 to 20 inches
Western Lake Superior
Late fall rains increased soil moisture before the cold weather season. Snow depths range from a few feet at some locations along the North Shore with lake effect snow, to 2 inches in northern Wisconsin around Bayfield. Modeled water content of the snow ranges from over 7 inches around the Pigeon River along the Canadian border to a few tenths of an inch around Bayfield County, Wisconsin. In the St. Louis River watershed, water content of the snow is in the 2 to 3 inch range in the upper part of the watershed and a little above 3 inches in the lower part of the basin. The reservoirs in this watershed are being drawn down and should be able to capture the spring runoff in their respective areas
UPPER MISSISSIPPI RIVER DRAINAGE
Minnesota Tributaries to the Mississippi River
Minnesota River Basin
Soils remain very wet across the basin as a result of above normal late summer and fall precipitation. August through December precipitation ranked from 150 to 200 percent of average over the basin. The Standardized Precipitation Index categorizes conditions as very wet to extremely wet in the upper portion of the basin. Streamflow also indicates very wet conditions, with baseflow levels remaining above the 90th percentile. While the winter began with above normal snowfall from early season storms, the trend has reversed over last few months with lower than normal snowfall. The warm temperatures in January depleted the existing snow cover over most of the lower basin below Redwood Falls. This region currently has little to no existing snow cover, with only a few tenths of water equivalent present. In the upper basin above Redwood Falls, the snowpack increases toward the west, with the heaviest amounts above La Qui Parle reservoir. While some of the snow melted during January, there is still 2 to 3 inches of water equivalent in the upper basin. Little to no frost exists in the basin, as the warm temperature pattern in January depleted what little frost had accumulated in the area. Some frost is redeveloping with the recent trend back toward the colder temperatures normal for this time of year. But with only a couple of weeks remaining until the frost peaks, this will not allow enough time for a significant frost layer to develop
Mississippi River Tributaries in Wisconsin
Chippewa River Basin
October and November precipitation was about 125 percent of normal. River flows were normal during most of the fall over the Chippewa basin. Currently, most of the basin has snow cover and the resulting snow water equivalents ranged from a quarter inch south to around 3 inches in the north. Frost depths are shallow over most of the basin. Current model states indicate the upper soil levels are saturated over the entire basin. About 1 to 4 inches of new snow fell as a result of the mid February snow event.
Wisconsin River Basin
The US Drought Monitor showed the headwaters and the confluence area of the Wisconsin River basin to be abnormally dry until the end of January. River flow at Muscoda, Wisconsin have been between the 50 percent and 20 percent values for the past couple weeks. The current modeled soil moisture states indicate that the warm temperatures in January have brought soil moisture into the above average category. Current snow depths in the basin range from 22 inches in the headwaters to zero below Petenwell Dam. The snow water equivalent ranges from 3 inches in the headwaters to 2 inches in the central part of the basin. Some of the larger reservoirs on the Wisconsin River, like DuBay, Petenwell and Castle Rock are being drawn down at this time, in anticipation of capturing the run-off when it occurs. All of the other smaller rivers that are part of the Wisconsin River Basin, have modeled soil moisture states have very wet soils. The Trempeleau River flow is currently is at a 20 percent of normal, but the Black River is currently between the 50 percent and 80 percent of normal and the La Crosse River is at less than the 80 percent. Snowfall from the mid February storm event averaged 4 to 9 inches over the Wisconsin River basin.
Mississippi River Tributaries in Iowa
Skunk, Wapsipinicon, Maquoketa,Cedar and Iowa River Basins
Streamflow during the Fall of 2005 in these river basins was normal and that condition continued into the first portion of 2006. Precipitation was 50 percent of normal during September, but generally rebounded to the normal range for November and December. There is current no ice cover on streams, and no frost is being reported. Coralville Reservoir is currently undergoing the winter draw down. Modeled soil moisture states are wet in the upper layer across these basins. Some holding capacity is available in the lower layer. A mid February storm deposited 1 to 5 inches of new snow over the northern reaches of these basins.
Des Moines River Basin
Precipitation during the fall was 70 to 90 percent of normal for the western portion of the basin and 50 to 70 percent for the eastern portion of the Des Moines River basin. River flow were normal during the fall according to the USGS. January precipitation was a half inch or less to 1 inch for the upper part of the basin, increasing to 1 to 1.5 inches in the middle basin and up to 2 inches or more near the mouth of the Des Moines River. Temperatures from November to mid February were 3 degrees above normal in the upper basin and about 4 degrees above normal for most of the lower basin. There has been very little snow cover over the basin. This winters snowfall is the lowest since 1989 according to Climatology Bureau, Iowa Department of Agriculture and Land Stewardship (IDAL). There is currently little to no frost in the Des Moines River basin. The current flow in the Raccoon River is about 20 percent of normal. At Stratford, the flow is about 250 percent of normal. The current Saylorville Reservoir release is 400 percent of normal and it may vary to keep the pool elevation steady. Red Rock reservoir release is about 170 percent of normal and target pool elevation is 742.2 ft to 742.4 ft. The flow in Des Moines River depends on the regulation of these two reservoirs. The simulated model states indicate the the upper zone of soil moisture is 90 percent of capacity and lower zone is 30 to 50 percent of capacity.
Mississippi River Tributaries in Illinois
Illinois River basin
Summer 2005 conditions over the Illinois River Basin continued through the fall months. Soil conditions were dry throughout the basin. River flows continued to be 25 percent of normal. The precipitation totals were low except for November when precipitation was 110 percent of normal. Precipitation totals in Illinois during January were above average across the state. This created near-surface soil moisture conditions that were close to normal statewide according to the Illinois State Water Survey (ISWS). Currently, soils are generally very wet as indicated by the model states, even though basin flows are classified as below normal for the 7-day average streamflow by the USGS. The wettest areas are the Calumet, Fox, Des Plaines and Kankakee River Basins. At the current time, there is little or no snow within the southern two thirds of the Illinois River Basin. There is no reported frost at this time. About 8 to 12 inches of new snow was reported in the Fox River Basin as a result of the mid February snow storm.
Rock River Basin
During the fall, the ongoing drought conditions continued in northern Illinois and southern Wisconsin. River flows were 10 to 25 percent of normal. Fall rainfall was only 10 to 50 percent of normal. Late 2005 river flows were 10 to 25 percent of normal, which was reflected by the lack of precipitation. January temperatures were unseasonably warm and precipitation as 150 percent of normal, (as shown above in the Illinois River Basin discussion) relieving some of the drought conditions temporarily. Frost depths have been less than 1 foot and currently 6 inches or less is common across the basin. By early February most of the winter snow had melted but the February 16th snow event provided up to 10 inches in the northern portion of the basin. A few minor ice jams occurred in January in the Rock River but no flooding was reported.
Kaskaskia and Big Muddy River Basins
Fall precipitation was 25 to 50 percent of normal during October and December and 150 percent of normal in November. Fall river flows, were normal according to the USGS. Precipitation for January was near normal. While recent rainfall has increased soil moisture in the upper layers, the deep soil moisture contents are near normal for this time of year. Currently, no snow or frost exists in the basin. Streamflow levels are currently near seasonal normals on the Big Muddy to a little below normal on the Kaskaskia River.
Tributaries to the Mississippi River in Missouri
Fabius, Fox, Salt, and Cuivre River Basins
The northeast Missouri tributaries entered the winter season with drier than normal antecedent conditions. The trend continued in November and December with below normal precipitation. Minor recharge occurred with above normal precipitation in January, but at mid February the rivers were at low baseflow with flows ranking below the 25th percentile. Due to the low flows, occasional channel freeze-overs have been noted at some gage locations. There was no snow in the basin at mid February. However, spring flooding in northeast Missouri typically occurs from short duration intense rainfall and fast runoff events in the spring.
Meramec River River Basin
Last fall river flows were near normal according to the USGS. Precipitation was 100 to 200 percent of normal in September and November and 50 percent of normal in October and December. Currently the Meramec River flows are normal while current soil moisture conditions are fairly saturated due to recent rain events. There is currently no snow cover or frost in the Meramec River basin.
Mississippi River Mainstem
Mississippi River from the Headwater Area to Red Wing, MN
During the summer of 2005, precipitation was normal throughout the basin. However, fall precipitation was 125 percent in the north and southeast, but as high as 200 percent of normal across the central portion of the basin including the Crow River, Elk River, Rum River, Sauk River, and the Crow Wing River. Frost depths throughout the basin are about a foot or less, which is about a foot shallower than last year. Also, there are no reports of ice layers in the snowpack at this time.
Model simulated water equivalents range from about a quarter inch in the Cannon Basin in the south to about 2.5 to 3.0 inches in the Crow Wing Basin in the northwest. These simulated amounts are below average compared to simulated averages for the last 50 years. As a result of the wet fall, some midwinter snowmelt, and a shallow frost, flows are above normal for this time of year. Except for a slight moisture deficit in the headwaters area, modeled soil moisture states are quite wet.
There have been several ice jams this winter on the Mississippi River at Fort Ripley, Minneapolis, and Anoka and on the Sauk River at St. Cloud. These have been mainly freeze-up ice jams which occurred earlier in the winter, but have dissipated during the relatively warm month of January. Recent cold temperatures have been affecting river levels slightly, but with a relatively degraded ice cover this late in the season, ice jams this spring are not a big concern in this basin. The pool levels at the headwaters reservoirs are being held 0.50 of a foot above the normal drawdown level for the winter because of the below normal snow water equivalent in these these basins.
Mississippi River from Lake City, MN to Lock/Dam 10 at Guttenberg, IA
Precipitation was 100 to 125 percent of normal in November 2005, creating wet antecedent conditions going into the winter months. Since then, precipitation has been about 50 percent normal. Deep soil moisture is a little below normal, especially over the northeast Iowa portion of the basin. Snowfall has been about 1 foot below normal. The early snowpack melted and in early February snow was almost non-existent. Frost depths are shallow and much of the mid-winter snowmelt runoff has moved into the upper soil layers. On the mainstem Mississippi, only L/D 10 was reporting 100 percent ice cover in the pool. Lake Pepin ice thickness is about half of typically observed. River ice jams have been minimal. Faster flowing tributaries have experienced some shore ice and only a few tributary gages were showing signs of minor backwater from ice. Current streamflows are about double the long term normal on both the tribuaries and the mainstem Mississippi River. A mid February snow storm was responsible for 3 to 5 inches of new snow. This was followed by an arctic air mass moving into area. The new snow cover will help insulate soils from what will probably be the coldest week of the winter in this reach.
Mississippi River from Lock/Dam 11 at Dubuque, IA to Chester, IL
Drought conditions were prevalent in this reach of the Mississippi last summer, with some precipitation relief coming during the fall and winter. November was the only month reporting above normal precipitation of 100 to 125 percent. River flows were normal during the fall and continue to be so at the present time according to the USGS. There currently is little to no snow cover, and no ground frost being reported. Tributaries and pooled areas of the mainstem Mississippi are ice affected.
Mississippi River from Louisiana to Chester, IL
Fall flows on this reach of the Mississippi were classified as normal according to the USGS. Precipitation was 10 to 50 of normal during October and December and normal during November. River levels and flows were slightly higher than normal due to the warm weather maintaining base flow contributions until this past week. Cold air effects dropped levels at some locations 1 to 2 feet. As the cold air is replaced with warmer air, a rebound in levels and flow is expected. There currently is little to no snow cover and no ground frost being reported.