Giving Gov. David Ige more than a year’s notice, the U.S. government is threatening to suspend the sale of federally backed flood insurance in Hawaii unless the state amends or revokes a state law that conflicts with the national insurance program.

Such a suspension could end coverage for 60,000 policy holders statewide and jeopardize Hawaii’s eligibility for some federal disaster assistance.

But the state says it won’t come to that.

In a letter sent to Ige in mid-April, the Federal Emergency Management Agency said the state has until July 31, 2017, to amend or repeal the law or FEMA would start proceedings to suspend Hawaii’s participation in the National Flood Insurance Program.

The vast majority of flood insurance polices in Hawaii are issued through that program, representing more than $13 billion in coverage risk here. FEMA administers the program.

The law drawing the agency’s attention was enacted to help Hawaii farmers and ranchers, exempting the construction of certain agricultural structures from building code requirements.

That same law has become the center of a growing controversy at Kunia Loa Ridge Farmlands, an off-the-grid agricultural development where dozens of unregulated structures have been built. One recently was erected in the middle of what farmers say is a dry streambed.

The state already is working with FEMA and the counties to propose amending the law in the next legislative session, according to Jodi Leong, a spokeswoman for the governor. The session runs from January to May.

“Compliance with federal requirements will ensure that federal flood insurance and federal disaster assistance will continue to be made available in the state,” Leong said in an email.

The state does not plan to repeal the law, recognizing that it was designed to help farmers, ranchers and the agriculture community, according to Carty Chang, chief engineer for the Department of Land and Natural Resources.

The statute, adopted in 2012 and amended the next year, was meant to spare farmers and ranchers the time and expense of getting building permits to erect tool sheds, storage facilities and other nonresidential agricultural structures under 1,000 square feet.

The exemption applies only to structures built on commercial farms and ranches outside the urban district.

Roy Wright, FEMA’s deputy associate administrator for insurance and mitigation, wrote Ige in mid-April to put the state on notice about the possibility of suspending the insurance program.

Communities participating in the program must require permits for all proposed construction or other development so that regulators can determine whether such activities are proposed within flood prone areas, according to Wright’s letter.

Through the insurance program, which is voluntary, the federal government makes available affordable flood insurance in exchange for communities adopting regulations that are consistent with federal standards designed to minimize flood risks, including in the construction of new buildings.

Wright said Hawaii’s exemption law creates a legal impediment for complying with the insurance program’s requirements, placing the state and counties’ continued participation in jeopardy.

John Hamill, a spokesman for the FEMA region that includes Hawaii, said officials with the city informed the agency of the law’s potential incompatibility with the flood program shortly after the measure was passed.

The city opposed adopting the law, citing health and safety issues.

Hamill said in an email to the Star-Advertiser that the risk to Hawaii if the insurance program is suspended is “real and substantial.”

Since 1978, more than $87 million in claims have been paid under policies issued through the program, according to FEMA.