After a decade-long burst of runway projects, U.S. airports’ infrastructure plans are projected to fall slightly over the next five years, but total a still-substantial $32.5 billion, the Federal Aviation Administration says.

FAA’s latest biennial National Plan of Integrated Airport Systems report, posted on its website on Oct. 21, says that the 2017-2021 estimate of $32.5 billion is a dip of $1 billion, or 3%, from the agency’s last such study, released in 2014. The new total also is down sharply from the recent peak of $52.3 billion, in the report FAA issued in 2010.

FAA’s figures are just a subset of total airport construction and other capital improvement needs because they are confined to projects eligible for federal Airport Improvement Program (AIP) grants. That universe generally excludes costs of terminal construction and expansion work, only a small fraction of which is eligible for AIP funding.

A March 2015 Airports International Council-North America report, which covers a wider range of airport project types, pegged capital needs at $75.7 billion in the 2015-2019 span.

In FAA’s new report, sent to Congress on Sept. 30, it says that the dollar volume of projects to refurbish runways and other airfield pavement and expand or renovate terminals will rise 3% from the previous five-year estimate. On the other hand, projects designed to boost capacity will decline by 24%.

Reconstruction accounts for the largest share of the total needs, at $11.5 billion or 35.3%. Capacity-related projects are estimated at $3.7 billion, or 11.4% of the total.

The study also notes that airports have wrapped up a busy period, extending for more than a decade, in which they constructed 27 new runways or extensions or airfield reconfigurations.

Still, some airports have big plans. Among the largest are: Chicago O’Hare, with an estimated $740.8 million; Houston’s George Bush Intercontinental, with $626.1 million; New York’s LaGuardia, with $435.9 million; Los Angeles International, $388.6 million; and Philadelphia International, $322.8 million.

Others include San Diego International, $313.3 million; Dallas-Fort Worth, $211.5 million; Salt Lake City International, $177 million; Hartsfield Atlanta $157.9 million: and New York John F. Kennedy International, $151.3 million.

FAA says that its estimates are based mainly on airport and state master plans that planning and engineering firms produce for airports and public agencies.

The FAA study includes 3,332 existing and eight proposed airports, heliports and seaplane bases. An air-travel facility must be included in the plan to be eligible to receive AIP grants. The grant program’s 2016 appropriation was $3.35 billion.  A temporary FAA reauthorization continues the program’s funding at that level through Sept. 30, subject to an appropriation.

Construction industry and airport officials are hoping that, when lawmakers draft a new FAA authorization next year, they will boost the allotment for AIP.

Airports use a variety of other financing sources, sometimes in combination with AIP money, to fund capital projects, including the bond market and passenger facility charges.