Despite heavy rain to the north, only minor flooding expected along Rock River

Despite heavy rain to the north, only minor flooding expected along Rock River

By Neil Johnson
May 13, 2014
JANESVILLE—Widespread, gully-washing rains on Monday dumped between 2 and 6 inches of rain into the Rock River basin, but weather forecasters expect only minor river flooding in Rock County.

On Tuesday, river gauges on the Rock River at Afton and Lake Koshkonong showed water levels within 6 inches of reaching minor flood stage. Forecasters expect the river to peak Friday at 9.1 feet at Afton and 10.3 feet at Lake Koshkonong.

That means low-lying farm fields along the river likely will get swamped with floodwaters.

More rain is expected later this week, but unless the area sees continued heavy rainfall, forecasters say it's unlikely flooding this spring could approach anything close to floods of 2008 and 2013.

According to National Weather Service data, Rock County had 2.3 inches of rain Tuesday. Areas along the Rock River farther north, such as Watertown, saw nearly 6 inches of rain.

All that water is moving downhill toward Rock County, but Rudy Schaar, a meteorologist at the National Weather Service's Sullivan office, said the Rock River can mostly handle it.

“We were lucky. The river has been on the high side, but it was mostly within its banks before the Tuesday rain event started,” Schaar said.

He said rains expected later this week are factored into the predicted crest later this week.

“If we get the next round (of rain) that's predicted on Thursday, if we get some thunderstorms that cause a few more gully washers in the basin, it could get more significant, but right now, it's nothing major,” he said.

Rock County residents have been getting accustomed to the annual threat of floods.

In April and May 2013, Rock County had 13 inches of rain, most of which happened in a span of about two weeks in early April. That caused major flooding in Rock County, where floodwaters on the Rock River reached 11.5 feet at Lake Koshkonong and Afton.

So far this spring, Rock County has only seen about half that amount of rainfall.

In 2008, when the Rock River surged to a record high 13.5 feet at Afton, 21 inches of rain fell between April and June. That came after a winter during which the area recorded 84 inches of snowfall.

“That year, the snow melted rapidly. Then, there was a very wet spring and early summer. Basically, the whole area started out as very saturated, and river levels were high to start with. There was no place for the water to go," Schaar said.

This past winter, Rock County had 60 inches of snow, but Schaar said the snow melted much more slowly.

Rock County Chief Deputy Barb Tillman said the sheriff's office plans to have patrols monitoring river levels every day this week.  

“You look at past history of flooding, but you have to go out and look in the field to get firsthand knowledge,” she said.

Weather patterns may be different every spring, Tillman said, but what doesn't change is the fact that water runs downhill.

“We're kind of watching Jefferson County to see how (heavier rains there) could impact Rock County,” she said.

Tillman said the sheriff's office emergency management department has planned to meet with officials in the town of Milton, town of Fulton and Afton on Wednesday to form a plan in case any areas along the river need sandbagging.

“As it stands, we're in good shape. We've got a supply of sandbags on hand, and we're working with the town chairs to make sure we can meet all their needs,” Tillman said.

Flooding Not as Severe as Predicted (So Far)

Koshkonong has Crested….

Rock River Flood Inundation Mapping Project Update

I wanted to let everyone know that Terry Zien, USACE St. Paul District, called me on Friday and advised that the USACE is still waiting for funding for the proposed Flood Inundation Mapping Project for the Rock River  (yes, it is still alive!)  The USACE is waiting for their FFY 14 budget and have been operating under a continuing resolution.  Those projects submitted last year are being considered for funding in the FFY14 budget.  Shirley Johnson along with WDNR have done some work, but can’t move forward until there is an approved budget.  Terry advised that they are expecting to receive funding soon.   

It’s like FEMA, we are still waiting for funding for last year’s PDM grants, yet FEMA is asking for applications for this year! 

In any event, I’m pleased that the project still has movement. 

Roxanne K. Gray

Mitigation Section Supervisor

State Hazard Mitigation Officer

608-242-3211

Lake Levels to Jump

flood risk normal in Janesville

Planting for farmers delayed because of frozen ground, flood risk normal in Janesville

By Andrea Anderson
March 31, 2014
JANESVILLE— Sunday's sunshine and warmer weather make the lower winter temperatures feel like a distant memory, but for local farmers winter is far from a memory and is putting a dent in plans.

The frozen ground is delaying local farmers' planting schedule.

Farmers have to wait until the ground is thawed and dry enough to get on the fields to prepare for planting. They also are unable to plant crops when the soil is too cold or too wet.

Doug Rebout, a local farmer, is normally out working the fields this time of year to prepare for the first day of planting on April 15. Because of this year's frozen ground he's not.

Instead, he's waiting for the ground to warm up and for the soil to dry out.

“It's not like we go out and measure the temperature or anything, it's just more of an instinct,” Rebout said.

Rebout plants 2,600 acres of corn, 1,000 acres of soybeans, 150 acres of winter wheat and a couple hundred acres of hay.

He won't be planting by April 15 and doesn't have an exact date when he will begin.

“Mother nature is your main thing that tells us when we can and can't go,” Rebout said.

Last year planting began April 28.

Once crops are planted it doesn't mean it's smooth sailing. There could be heavy rain, droughts or other conditions that delay harvest.

Rebout is waiting patiently and he hopes others will, too.

“Once we get going we're going to be putting in a lot of long hours, we hope people are patient with us on the roads,” Rebout said.

The winter that would never end, and still hasn't for some, could have been a blessing in disguise.

As spring approached, the weather was warmer one day and colder the next, allowing for a gradual snow and ice melt and leading to a gradual rise in Rock River water levels.

These are ideal conditions to keep the risk of flooding as low as possible, said J.J. Wood,  National Weather Service meteorologist.

“You want it to be a gradual melt,” Wood said. “Then if you do have runoff, it's not going to raise the level of the river too much.”

Certain parts of the Rock River have a 50 percent chance of flooding by June, according to the river's forecast completed by the National Weather Service.

The forecast depends on precipitation, snow melt and soil conditions.

The forecast is normal, Wood said.

According to measurements, the river's water level in Afton is up 6.7 feet from about 4 feet at the beginning of the month, Wood said. The flood stage, or the point where water begins to flood roads or reach homes, is 9 feet.

“Right now I would say it's in a normal type of range for this time of the year, it's nothing unusual,” Wood said.

For the river to exceed flood stage at least once or twice by June is not out of the question, unless there was a drought, Wood said.

Ground temperature also contributes to flooding.

If large amounts of rain fall and the ground remains frozen or does not thaw enough, the majority of that rain will not be absorbed by the soil and will end up in the river, increasing water levels.

Where is the REAL OHWM?

RKLD is already collecting data - we are examining the OHWM and whether hunters and fisherman can access more public areas on the lake.

In some cases, wetland owners may be claiming public waterways as private property.

___________________________

Brian..

 

Below is information about the Rock River flood inundation pilot project.   See the link for the Cedar River-Cedar Rapids, IA river gauge for an example of what flood inundation mapping is like.  Let me know if you are interested in getting on an e-mail list for the meeting or conference call in early 2014. 

--

Brian Hahn-Service Hydrologist  12/10  635 pm

National Weather Service-Milwaukee/Sullivan, WI

N3533 Hardscrabble Road

Dousman, WI 53118

More storms could mean more flooding in Rock County area

By Gazette staff

Tuesday, June 25, 2013

---

Although a flash-flood warning for south-central Wisconsin has ended, the area could still be hit with thunderstorms this week, and flooding could become an issue if that happens.
Meteorologist Marcia Cronce from the National Weather Service said the warning was for weather rolling through the upper Midwest. Sunday night, a weather system went through Iowa and reached northern Illinois.
“If we do get under one of these big complexes, then the risk is there that we would have some flash-flooding concerns,” Cronce said.
A large complex of thunderstorms could develop anywhere in the upper Midwest between today and Wednesday. Even without substantial additional rain, the Rock River is likely to reach a minor flooding point by Monday, Cronce said.
The river is expected to reach 9.3 feet at Afton Road south of Janesville in the next week.
Flood stage is declared at 9 feet, which the National Weather Service describes as “minor flood damage … in lowland and agricultural land adjacent to the river.”
Current predictions are “based on a forecast precipitation amount at a conservative level.” Cronce said she does not know when the rain will occur, so the forecast could change.
“We are in a weather pattern where a thunderstorm complex can roll through and dump very heavy rain on any part of south-central Wisconsin,” she said.

---

Published at: http://www.GazetteXtra.com/news/2013/jun/25/more-storms-could-mean-more-flooding-rock-county-a/

Prediction from USGS - Here we go again Lake Koshkonong

Lake Koshkonong; Top 15 Water Levels all time

#1    6/21/08    15.12**

#2    1959          13.00*

#3    4/23/13    12.39

#4    4/25/93    12.23

#5    1979          11.74*

#6    4/18/08    11.65**

#7    6/05/04    11.49

#8    6/07/00    11.02

#9    4/07/07    10.58**

#10  8/30/07    10.46**

#11  4/23/98      9.77

#12  4/28/99      9.73

#13  3/23/90      9.45

#14  3/21/94      9.19

#15  3/14/97      9.02

 

*Estimate using flow chart

**Two month’s or more between levels 

Another Week, Another Foot Down

May 1 = 781.39
May 8 = 780.32

So, we lost another foot of water level during the past week.

Depending on rain, we should lose another 1ft during the next week, then begin gaining speed.

But likely, Memorial Day weekend will be a SLOW NO WAKE boating holiday weekend.

Common Question on Lake Koshkonong Flood Storage

We get this one every time there is high water or a flood stage - if we increase the operating orders for the summer by 7 inches, would the flood of 2013 be that much worse - 7 inches higher than what is was at crest?

Hydrology simplified; 

7 inches = 6,000
Flooding = 1,000,000

Flooding brings 167x more water than what our modest request for 7 inches would bring.

This is taken from the FAQ page.

_________________

...The reason for this is the contrast between the volume of water occupied by the proposed water level increase and the very much larger volume of water contained in a large flood on the Rock River, combined with the hydraulic characteristics of Indianford dam. 

Specifically, if the Lake water elevation was at the proposed target -- 7" higher than the current operating order target, the increased volume of water of water in the lake would be approximately 6,000 acre-feet -- 7 inches over approximately 10,000 acres. 

In comparison, the 2008 flood volume that flowed through the Rock River was over 1,000,000 acre feet. Because the flood volume is so much larger than the storage "lost" in the lake due to the proposed operating order change, the water level in the lake at the beginning of a flood has little effect on the peak discharge that moves out of the Lake. 

In summary, the proposed summer target water level increase is an infinitesimal fraction of the typical flood flow, meaning that peak discharge in the Rock River would be unaffected, and the Lake levels at flood time would be controlled by the inoperable crest of the Indianford dam and the Rock River downstream, and not the gate settings associated with the revised operating order.

One week ago today...

Lake Koshkonong crested at 782.39

Today 781.39

Down 1 ft, or 1.7 inches per day.

When we get closer to 2.25 to 2.5 inches per day, we will be off the bank and dropping from the channel.

Still 5 feet OVER summer Max of 776.3

Anchor Inn, Newville, USA

Anchor Inn, Then, 2008

Anchor Inn, Now, 2013

1960s Flooding??

Does anyone have photos of Lake Koshkonong flooding from the 1960s?

We have newspaper articles from the flood of 1959 - and the 2008 flood was higher - but I cannot find what this person is referring to.

________________

YOUR VIEWS

   

   Record flooding in 2008? What about back in ’60s?

   Officials say the flooding on the Rock River this spring got close to the highest ever, which they say occurred June 21, 2008. They had better check their records. 

Back in the 1960s, the Rock River was up just a few inches below the Newville Bridge. The Anchor Inn in Newville was flooded, and water was 2 or 3 feet deep in the building of another bar called Snug Harbor, now Harbor Recreation. 

The water was almost up to Highway 59 between Milton and Newville. I have been told that, at the time, Otter Creek north of Milton backed up into Bowers Lake and Storrs Lake. 

At the time, walleyes went up Otter Creek and got into Storrs Lake. That summer people caught walleyes in Storrs Lake, and they had never caught them in there before. 

You can ask most any older person who lived around Newville in the ’50s and ’60s, and they can tell you about this. 

JOHN R. BERGMAN 
Milton

Lake Koshkonong Crested Early Thursday AM

Yesterday =782.24 --- inflow = 8,960 cfs
Today = 782.13 ---- inflow = 8,310 cfs

1 1/10 of an inch drop.

April Wettest on Record

www.chicagotribune.com/news/local/breaking/chi-snow-showers-a-week-before-may-20130424,0,6223531.story

chicagotribune.com

Snow showers, a week before May

By Adam Sege
Tribune reporter
7:38 AM CDT, April 24, 2013

Next week will be May and temperatures will be in the 70s. But first we'll have to get through this April, and that means yet another chance of snow.

Tonight's temperatures are expected to dip into the low 30s, bringing the possibility of snow showers after midnight, according to National Weather Service meteorologist Jim Allsopp.

"You might be getting a dusting in grassy areas," Allsopp said.

But any accumulation is not expected to last. By Friday, highs will be in the 60s and temperatures are expected to steadily rise through the weekend and reach the 70s by Monday, Allsopp said.

April has been cloudier and colder than normal. And it is now officially the wettest. As of midnight, 8.54 inches had already fallen this month. That beats the previous record of 8.33 inches in April of 1947.
After tonight, the rest of April looks fairly, dry, Allsopp said. But forecasters know that could well change. "This time of year, things can change pretty rapidly," he said. "So well have to keep an eye out.”

Many areas got close to an inch of rain Tuesday, aggravating flooding from last week's deluge. 

Lake Koshkonong to Crest tonite

yesterday = 782.36
today = 782.39

INFLOW from Jefferson (as measured at Fort Atkinson gauges)
yesterday = 10,500 cfs
today = 10,000 cfs

Sandbagging Lake Koshkonong Photos in Milwaukee Journal Sentinel

Edgerton HS Sandbagging Lake Koshkonong

Indianford Dam Safety Checked by DNR today

Update – Rob was on site and noted the dam was submerged and has freeboard available to accommodate the additional 0.5FT increase predicted for the lake without overtopping the abutment.  There is currently 18 inches of freeboard available.

He has told Paul France(Regional WEM) and representatives of Rock County that he recommends not doing anything at this time and re-evaluate should the water levels rise above the predicted levels.

Thanks.

Bill

P William D. Sturtevant, P.E.

State Dam Safety Engineer

Dam Safety Floodplain Section

Bureau of Watershed Management

Wisconsin Department of Natural Resources

(() phone:     (608) 266-8033

Indianford Dam being checked today

All,

Rob Davis, Dam Safety, is on his way to the Indianford Dam on Lake Koshkonong at the request of WEM. Rob will be making the decision related to a request to place fill on the right and left abutments of the dam to prevent the flow of water around the structure. Similar work was performed in 2008 when the lake reached record elevations.

Rob will be reviewing the request based on the physical situation at the dam and whether or not the work is actually necessary to protect the structure and the public. NWS has predicted a flood elevation on the lake at 12.5ft which is 2.6 feet lower than the elevation reached in 2008. The lake is currently at elevation 12.07ft.

Updates to follow.

Bill

P William D. Sturtevant, P.E.

State Dam Safety Engineer

Dam Safety Floodplain Section

Bureau of Watershed Management

Wisconsin Department of Natural Resources

(() phone:     (608) 266-8033