The city of Austin will mine for gravel at a flood mitigation site off Fifth Street and Third Avenue Southeast, and may use some of the material for its Oakland Avenue project scheduled to begin later this summer.

“There is 25,000 cubic yards of material that can be used for street-improvement projects,” community development director Craig Hoium said. “That material can be used for that project. It doesn’t have to be.”

Hoium outlined almost 20 conditions to the Planning Commission Tuesday designed to preserve the character, value and geography of the property, and to mitigate any adverse effects such as odor, dust, noise and hazards.

He said mining hours would be limited to 7 a.m. to 7 p.m. Monday through Saturday, and would be scheduled to conclude by Dec. 31. The outcome for the area affected will be new grading and landscaping.

“So basically where you leave it is where you’re going to find it, minus the new grading,” commission chairwoman Lynn Spainhower said.

Following approval of the mining effort, planning commission members discussed and approved plans to fill the Oakland Avenue East underpass with 4,000 cubic yards of material, recognizing that the project must also be cleared by the Minnesota Department of Natural Resources.

The city council already approved construction plans — demolition of three bridges and street improvements between First and Fourth Streets Northeast — for the $2.86 million project, though planning members wondered, like several community members, whether filling the underpass would pose more severe flooding issues for those to the east.

“It fills those bridges first,” said Richard Chinander, pastor of New Life Vineyard Christian Fellowship. “I just want an assurance that we’re not treading water, so to speak, to make a problem that is already there worse.”

Assistant city engineer Steven Lang provided that assurance, citing the results of a study done by Short Elliot Hendrickson Inc., a consulting firm specializing in water issues.

“They found no adverse effect by filling in the underpass,” Lang said.

Following a visual inspection and models, SEH said in a letter dated May 30 that “(t)he loss of storage area as it relates to the hydrologic conditions for the Cedar River can be considered negligible because of the area’s size relative to the cumulative contributing drainage basin.”

In other words, Hoium said, Austin has 800 more acres of area to retain water.

“It looks like a large volume of water there,” Hoium said. “But when you look at all the water coming in that bridge, that is actually a small amount of water coming into that area.”

“I understand what you are saying is that it’s a thimble — and that once the street is graded that it’s not going to push all that water into Chauncey (Apartments) or businesses there,” Spainhower replied.

Yes, Hoium said, adding, “If there was an adverse condition that would have created from this project, I don’t think the recommendation to the planning commission or even the council would have taken place.”

In fact, the city has outlined multiple benefits from the project, which is several years in the making. In documents, city engineer Jon Erichson said the project will eliminate long-term maintenance of bridges and associated cost; eliminate low-bridge height restrictions on a roadway used for Interstate 90 detours; eliminate steep grading and reduce driving hazards; and improve pedestrian sidewalks, infrastructure and emergency access.

Though no detour plan has been officially mapped, Lang said the city would work to maintain access at Fourth and First Street intersections. In addition, he said, crews hope to minimize closures once construction engulfs those two streets.

“As we continue with the project, we will close the First and Fourth Street intersection, but we’re limiting the amount of time that those intersections can be closed,” he said.

Lang added that the engineer’s office is looking at detour options, including routes around Queen of Angels Catholic Church near 10th Drive Southeast.

The Oakland Avenue project became particularly controversial as the city was seeking federal and state approvals. Some wanted to preserve the historic value of the three railroad bridges, a point Chinander stated last night.

“I love the old decor of this city,” he said. “I like the way the bridges look. We’re taking away all the history of this town. That disturbs me a bit.”

In efforts to retain some of the history of the bridges, which look like two, Lang said the city is salvaging all of the bridge railings on the Third Street bridge and all the bridge plats for a landscaping plan on Second Street and Oakland Avenue East.

“The landscaping plan is the replicate the bridge — to create a memorial or give people something to view, something they can look at,” he said, adding that railings will also likely border a new parking lot near the Old Eagles building off Fourth Street and Oakland.

The city received $1.68 million in federal grant money for the project. It received federal authorization for the project last year, but still awaits clearance from the DNR.