Last week’s third-worst flood in Austin history was a unique one, affecting neighborhoods, rivers and infrastructure differently, though, thankfully, less severely overall compared to years past.

“If you remember the 2008 flood in ’78, it devastated the community,” city engineer Jon Erichson said. “A lot of people don’t realize all of the changes that took place. If these things wouldn’t have happened, we would have been devastated one more time.”

Preliminary assessments suggest that Austin incurred about $1.2 million in public infrastructure damages, the majority of which is concentrated at the local waste water treatment plant, Erichson suspects. Though more won’t be unknown until water levels recede completely, Erichson said a digester recently cleaned may have suffered floor damage, which, if confirmed, “increased the damage assessment significantly.”

“Why hasn’t it happened before? Because it’s always been full,” Erichson said.

The city engineer attributed the treatment plant issues and the furiousness of the flood, which caused near-record water levels in the Cedar River, Turtle Creek and Dobbins Creek, to saturated soils across the region.

“So it created a much faster flood event,” Erichson said.

Water levels in Dobbins, in particular, vastly varied from 2004; last Thursday, it reacted most quickly to Wednesday thunderstorms, reaching record levels of 18.95 feet. Erichson said it was minimally affected four years ago.

Erichson said saturated soils also shifted the type of damage in residential neighborhoods, which reckoned with ground water infiltration more often the sewer back ups in basements.

He estimated, however, that 75 or more homes avoided ruin because of mitigation efforts from 2004, which included relocating homes from regularly flooded areas. The engineer’s office used a set of criteria to determine which homes they would attempt to acquire, including repetitive flooding, flooding levels, infrastructure impact and continuity of property.

The $28 million plan is still under implementation, though has already resulted in business and housing relocation off East Oakland Avenue, Wildwood Park and other regions.

“Those are issues that aren’t there anymore,” Erichson said.

Erichson said the development of the Cedar Water Rivershed District, which received $2 million in grant funding from the Legislature this year, and the local-option sales tax, passed in 2006, also promise big returns in the future.

The watershed district hopes to reduce the amount of water entering the area by 20 percent, a goal Erichson called “lofty.”

He added that the local-option sales tax has garnered $1.16 million in funds this first year alone, about $350,000 more than projected. Erichson said this may put the Austin area at an advantage when seeing competitive grants, including through the Department of Natural Resources, which is currently working to parcel out about $30 million in flood hazard mitigation funds.

“We can bring a 50 percent match to the table, and a lot of communities can’t do that,” Erichson said, adding that about $80 million in flood grants were requested last session. “And I think that’s really important.”

Not all allayed damage, however.

Erichson said homes off East Side Lake weren’t as well-protected by a berm in the region as was hoped. Residents there will meet with the city this week to discuss solutions.

Drainage problems also persist near the Cresthaven Housing Addition and the Nob Hill Housing Addition, the former mostly due to flooded ditches and culverts. Erichson said the New Hope Lift Station near Packer Arena was protected by dirt brought in Thursday, and will escape future problems following the completion of a berm and wall structure from Second Avenue Northeast north to Packer Arena.

Though North Main Street avoided “significant” damage, Erichson said he emphasized to visiting politicians — including Gov. Tim Pawlenty, U.S. Rep. Tim Walz and U.S. Sen. Norm Coleman — that mitigation efforts to the downtown region are vital to the long-term safety of the city.

“One of the points we really tried to drive home is we have $10 million of need on North Main Street,” he said.

“(Austin Packaging Company) has expressed to us that they are very, very concerned,” Erichson said.

The Federal Emergency Management Agency, or FEMA, has already completed its preliminary assessment of the region, and awaits a request from the governor’s office for funding. No declaration has been made yet. Mower County damages may be included with totals from Houston, Fillmore and Freeborn Counties.

“So that determination is yet to be made, and currently we are working on a plan to deal with these affected areas,” Erichson said.

If awarded, FEMA funding would reimburse the city for 75 percent of its costs, money that Erichson and director of administrative services Tom Dankert said would likely arrive quickly. Another 15 percent will likely be reimbursed by the state of Minnesota, they said, which tends to be a slower process.

“That means 10 percent of the cost, if we are declared, that we are responsible for,” Erichson said.

Dankert said the city could use fund balance to cover its portion of cost.

“That’s exactly why we put fund balance in the funds — for these types of situations,” he said.