WASHINGTON — U.S. Sen. Angus King and Rep. Chellie Pingree are urging federal officials to be even-handed and transparent in considering appeals filed by coastal communities in southern Maine over new flood zone maps.

In separate letters sent Wednesday to the head of the Federal Emergency Management Agency, Pingree and King urged FEMA to allow cities and towns to submit their own reports with more detailed data on which areas are at risk of flooding and which are not. Such reports – typically prepared by engineers hired by the communities – often suggest different flood lines from those proposed by FEMA.

King and Pingree noted that FEMA took those locally generated reports into consideration the last time flood zone lines were redrawn, in 2009. This time, the agency has been “reluctant to accept the same data generated by engineers on behalf of other coastal communities,” Pingree wrote.

That discrepancy is potentially unfair, the two Maine lawmakers said. Some homeowners face increases in insurance premiums that could cost them thousands of dollars more per year, or could see new restrictions on developing their property because of the flood maps.

“Maine communities that contracted with engineers during 2009 now get the benefit of better maps,” King wrote to W. Craig Fugate, FEMA’s top administrator. “All communities in the affected region should have the same opportunity.”

“Communities that are going to be affected by new flood maps deserve the same treatment that their neighbors previously received and they deserve to see the data that FEMA has used to come up with these maps,” wrote Pingree.

Homeowners and community leaders throughout York and Cumberland counties are scrambling to digest the new FEMA flood maps in case they want to appeal. The 90-day appeal period is expected to open in March, with the new flood maps taking effect in 2015.

FEMA maps are used to calculate rates for federal flood insurance that often is required with mortgages for buildings in flood zones. The federal agency is updating flood maps for 350 coastal communities nationwide.

Some areas in York and Cumberland counties that have been considered at low risk of flooding would be redesignated as high-risk – likely causing sharp increases in insurance costs or restrictions on development while other property owners could have to buy insurance for the first time.

For instance, 42 percent of Old Orchard Beach would be within the flood zone, up from 28 percent under the current maps.

The nearby towns of Cape Elizabeth and Scarborough are examples of what Pingree and King suggest is FEMA’s inconsistent policy.

Cape Elizabeth hired an engineer in 2009 in an appeal that resulted in a redrawn flood zone lines. That data, based on the localized report filed with FEMA, was the basis for the new flood map proposed for Cape Elizabeth.

Scarborough did not go through that process in 2009, and FEMA’s proposed maps for the town are based on different benchmark assumptions than those used for Cape Elizabeth.

“There are some stark differences between the towns, of course, but the base assumptions used to review the towns should not be different. It raises huge issues of fairness,” Scarborough Town Manager Tom Hall said recently.

Scarborough estimates that 449 parcels of land and 480 buildings in town would be within the new flood zones.

In her letter to Fugate, Pingree asked FEMA to inform communities about how the agency will consider “region-specific data” offered by cities and towns. And if FEMA will no longer consider the local data, Pingree wrote, communities need to know why as they prepare their appeals.

The federal flood insurance program is in debt more than $24 billion, largely because of massive payouts after storms such as Hurricane Katrina in 2005 and Superstorm Sandy in 2012. In an attempt to put the program on a more stable footing, Congress passed a law in 2012 that would raise insurance rates by phasing out federal subsidies for millions of property owners, including more than 3,000 in Maine.

Some homeowners in Maine face a potential double-punch as their insurance rates rise because of changes to the flood maps and the loss federal subsidies. But there is momentum among some lawmakers to delay those premium increases.

Legislation scheduled for a vote in the Senate this month or next would delay rate hikes as long as four years while FEMA studies the affordability of the flood insurance program. The bill would delay premium increases for many properties affected by the new flood maps but would phase out subsidies for second homes or buildings that have been flooded repeatedly or severely damaged by a single event.