By Mike LaBella
---- — HAVERHILL — The flood wall that for decades has protected the downtown from potential disasters is about to get some federally required improvements.
The city is preparing to raise the concrete flood wall by two feet — a project aimed at preventing downtown flooding should the Merrimack River overflow its banks in a worst-case storm and also protecting property owners from big hikes in their insurance premiums.
Public Works Director Michael Stankovich said work is scheduled to begin early next month and be completed by the end of October.
He said Defelice Corp. of Dracut was hired to do the work because the company submitted the lowest responsible bid through a competitive bidding process required by the state.
But before work can begin, the city held a “pre-construction” meeting April 10 with the contractor and the engineering design team from AECOM, an international engineering firm with its worldwide headquarters in Los Angeles and offices around the world.
Stankovich said AECOM was selected last year to do the design work through a competitive bidding process as well.
He said the meeting was held to discuss how the project will proceed, as well as the schedule for the upcoming construction.
The project will cost about $5.1 million, which Stankovich said is less than a previous preliminary estimate of $6 million due to a “favorable” bidding climate.
The federal government has ordered the project, which will also allow 35 property owners along the waterway to continue paying for flood insurance at current rates.
The concrete wall, which is 30 feet high, has protected downtown Haverhill from being deluged by the Merrimack River since the 1936 flood, which left the business district under several feet of water.
Last month, the City Council paved the way for work on the flood wall to begin by approving easement agreements with four property owners to access their land for construction activities.
They included Riverside Place Condominium Realty Development Trust, 70 Washington St.; Alosky Realty Trust, 191 Essex St.; Kifor Development, 151-153 Essex St.; and the MBTA for a stretch of railroad track near Little River.
The city will pay $4,000 for the permanent right to access land behind the Riverside Place condos parking garage and a $1,000 licensing fee to the MBTA. There is no cost to the city for the other two temporary construction easements.
In November, the council approved the mayor’s request to borrow up to $6 million for flood wall improvements.
The city expects to receive an undetermined amount of state and federal money toward the final cost of the project.
Improving the 2,200-foot-long flood wall is critical because federal officials have warned they will decertify the 76-year-old structure if the work isn’t done soon.
Stankovich said that if the flood wall lost its certification, it would result in an increase in flood insurance rates for about 35 privately owned properties along the downtown stretch of the waterway by an estimated $250,000 in total per year.
Repairing the flood wall will also allow the city to remain in a program through which the U.S. Army Corps of Engineers would pay to restore the wall if it is damaged in a natural disaster such as a severe flood or an earthquake.
“If something like an earthquake was to damage the nearly half-mile long wall it could cost up to $80 million to repair and rehabilitate,” Stankovich said.
The flood wall is on the north side of the river, essentially between the Comeau and Basiliere bridges, and along Washington and Merrimack streets.
Regulators had set a deadline of last November for repairing and raising the 30-foot-tall wall by two feet but granted the city an extension.
The wall begins below the river bed and stretches above the level of the river.
The flood-control project has several parts: Repairing and raising the wall; renovating and cleaning the Little River conduit, which runs underground and connects that smaller river to the Merrimack; repairing the circa-1938 downtown pump station behind the Washington Square Post Office; and buying three mobile pumps for use in times of storm water overflow.
The city estimated the full cost of modernizing the existing pump station at $3 million, so officials decided to buy the mobile units instead.
Officials have said the mobile pump stations can also be used in other parts of the city in the event of major flooding beyond downtown. The 16-foot-high Little River tunnel is partially blocked with trees and other debris, officials said. Little River feeds into the Merrimack River through an underground tunnel which passes through the floodwall.
The city plans to borrow money for the project from the state’s revolving loan fund at 2 percent interest. Annual payments on the loan will be made from the city budget and from revenue from a small increase in sewer rates, Mayor James Fiorentini said.