As Minnesota’s rain-swollen rivers moved toward their crests, officials were busy Monday planning for the consequences as forecasters hoped for dry weather.

In downtown St. Paul, the Mississippi River continued its surge toward an expected crest of 20.5 feet on Thursday.

As of 1 p.m. Tuesday, the river was at 19.35 feet — major flood stage — at the Robert Street Bridge, and floodwaters had inundated Shepard/Warner Road as well as Harriet Island.

Thursday’s expected St. Paul crest would be the seventh-highest in more than 100 years of records. The highest crest was 26 feet — in April 1965. A level of 20 feet or more hasn’t been seen since 2001.

However, because of decades of flood-proofing, a 20-foot crest in St. Paul mostly entails the closing of low-lying roads and parkland and erecting a temporary floodwall around Holman Field and limiting the airport’s flight operations. No inhabited buildings would be immediately threatened.

The St. Paul Police Department announced Tuesday morning they were in the process of temporarily relocating their West Side impound lot, at 830 Barge Channel Rd. near U.S. 52 and Concord Street, due to possible flooding. More information is expected to be released Tuesday afternoon.

Still, Mayor Chris Coleman on Monday declared a citywide state of emergency.

Coleman’s declaration is an interim measure that will be taken up by the city council Wednesday, said Tonya Tennessen, communications director for the mayor’s office. The declaration is a first step in securing federal disaster funding.

The city projected flooding damage will cost it $1.7 million, which so far has included staffing the city’s Emergency Operations Center, closing parks and roads, erecting flood walls and barricades, adding reserve and off-duty police officers for public safety measures, deploying portable pumps and increasing crews for cleanup efforts, Tennessen said.

It is too early to know what the cost of the flood to the city will be, she added.

The last time the city declared a state of emergency due to flooding was in 2011. That year the Mississippi in St. Paul crested twice during spring flooding: at 19.02 feet on March 29 and 18.71 feet on April 10.

Meanwhile Monday, Gov. Mark Dayton and four other members of the state Executive Council voted unanimously to extend the state of emergency that the governor declared last week for up to 30 more days.

That authorizes state agencies, including the National Guard and departments of Transportation and Natural Resources, to continue to providing assistance to flood-stricken areas.

“We still have a building emergency,” Dayton said. Flooding continues as some rivers have yet to crest, so “there’s more work to be done.”

Last Thursday, he declared emergencies in 35 counties, including Ramsey and Scott in the metro area, as floodwaters closed roads, threatened public and private property, and submerged farm fields during the critical spring planting period.

In Newport, owners of about eight homes aren’t just worried about their basements. If their levee breaks, it will not be repaired — so their unprotected homes may have to be torn down.

“It is pretty stinking precarious,” said city administrator Deb Hill.

In 1969, the Army Corps of Engineers hastily piled up a three-block row of dirt and rock, to temporarily protect Newport from the flooding river.

But the levee is on private land, and the city never upgraded it. Hill said that it’s possible that when the river crests on Thursday, the levee could break.

Fixing it could cost as much as $10 million, she said. “It would not be cost-effective for that property,” she said. “Mother Nature always wins.”

In the past, Newport has survived spring flooding, when the ground inside the levee was still frozen. This year’s flooding is late in the season, said Hill. “The levee is soft,” she said. “I have heard it is not in good shape.”

On Monday at Beanie’s at Maui’s Landing, a marina in Lakeland on the St. Croix River, eyes were on the river forecasts.

The marina’s office already had about 6 inches of water in it Monday morning, but flood damage was not too much of a concern, as the building has a concrete floor and walls, along with raised electrical outlets, said owner Gary Mau.

What Mau is concerned about, however, is whether the river will crest in line with forecasts.

“If the water comes about 2 or 3 inches above what is forecast, we’ll start to get water in our garage and basement,” Mau said.

The St. Croix in Stillwater was at 86.72 feet at 1 p.m. Tuesday and was forecast to crest at 87.2 feet — minor flood stage — on Friday.

The high water prompted the Minnesota Department of Transportation to close the Stillwater Lift Bridge to Wisconsin. The bridge will remain closed until further notice and motorists must use Interstate 94 or Minnesota 243 as detours.

On the Mississippi in St. Paul, the high water has led city sewer crews to set up auxiliary pumping equipment at Broadway Street and Kellogg Boulevard, limiting access to the Union Depot transportation hub in Lowertown. As of Tuesday, access to parking in the depot’s Lot B will be via Sibley Street only. Metro Transit buses are stopping along the depot’s Kellogg entrance.

After touring flood-ravaged areas of northern and southern Minnesota last week, Dayton said he plans to assess flood damage Tuesday in Delano, parts of the Twin Cities, Chaska and Shakopee. On Wednesday, he is scheduled to review sandbagging operations in Warroad and parts of Koochiching County.

The 2014 Legislature allocated $3 million to a natural disaster emergency fund that Dayton can tap without calling lawmakers into special session. He expects the amount of damage to exceed that figure, but he said it’s too early to call legislators back to the Capitol.

“We need the water to recede before we can make a damage assessment,” he said. But he added, “My commitment is to get relief out as quickly as possible.”

The governor has not yet received a response from President Barack Obama on his request for a federal disaster declaration. Obama will be in the Twin Cities on Thursday for a political event, but Dayton said he doesn’t know if Obama plans any flood-related activities.

Meanwhile, Minnesota is getting a $750,000 emergency federal grant to start covering costs of repairing roads damaged by the floods.

Craig Schmidt, a hydrologist with the National Weather Service office in Chanhassen, said the winter’s heavy snow melted off “nicely” but that soils are saturated after the recent record-setting rainfall.

It will take a while for soils to dry and for water levels to come down, he said, though that process could be slowed if another wet weather pattern pushes through in the next few weeks.

The forecast for south-central Minnesota this week calls for relatively slight chances for thunderstorms — 40 percent or lower through Friday.

This report includes information from the Associated Press and the Free Press of Mankato.

Correction: A previous version of this article incorrectly state that the city of St. Paul had paid $1.7 million on flooding damage. The city expects to spend that amount, which so far has included staffing the city’s Emergency Operations Center.