WASHINGTON – The National Archives has brought in giant dehumidifiers to preserve historic documents in the wake of flooding that closed the building and other historic institutions and government structures in the nation's capital.
The Archives, several Smithsonian museums and some government office buildings have been closed since Monday, when water from a weekend of heavy rains overwhelmed storm drains and flooded basements.
No historic artifacts or documents at the Archives have been damaged by floodwaters, but electric wiring, climate control and other building systems in the basement sustained extensive damage from 8 feet of water, said Susan Cooper, an Archives spokeswoman.
"The threat to the records is not flood water, but humidity from the lack of air conditioning," she said Wednesday.
Stacks of genealogical and other records are threatened by humid conditions, although the Declaration of Independence, the U.S. Constitution and other "charters of freedom" are not at risk. The most valuable documents are in climate-controlled cases and are backed by special paper that absorbs moisture when the heat or humidity changes, Cooper said.
To protect the rest of the collection — including Abraham Lincoln's telegrams to his generals, audio recordings from the Oval Office and letters and diaries from some of America's most well-known historic figures — workers on Tuesday brought in the industrial-sized dehumidifiers powered by outside generators to stabilize the atmosphere inside the building.
The only significant damage, Cooper said, is to the William G. McGowan Theater, which shows a continuous short film about the Archives and a twice-daily movie about its most important documents. Water covered the stage and the first two rows of seats of the 290-seat theater, which opened in 2004 as part of an extensive renovation.
It was uncertain Wednesday when repairs to the theater or damaged building equipment would be completed or how much they would cost, Cooper said. The building will be closed at least through July 3, although a July 4 celebration is still planned on the building's front steps.
This is not the first time records maintained by the Archives, which has been open since 1935 and occupies two city blocks, have been threatened. A fire at a storage center in 2004 in Suitland, Md., set off a sprinkler system, soaking many documents. The archives brought giant refrigerated trucks to the site and workers saved most of the collection using a freeze-drying process.
At the Smithsonian, where the visitors' center and the American History and Natural History museums remained closed Wednesday, officials were just getting inside the buildings, said spokesman Peter Golkin. The only damage reported so far was to mechanical equipment in the basements, but officials were still tallying the damage.
Golkin was unsure if any steps were being taken there to protect the exhibits from humidity.
"We're aware of the potential for damage to our collection," Golkin said. "Our priority is to get the power back up."
The National Zoo's Amazon rain forest exhibit was closed Wednesday due to flooding and some parking lots were closed, but the zoo was open.
The National Gallery of Art also remained closed Wednesday because flooding had cut off the building's steam supply. The steam maintains humidity needed to preserve the paintings, a spokeswoman said. Although the building has backup systems, they are not designed to work when large numbers of visitors are inside.
The headquarters of the Justice Department and the Internal Revenue Service were to stay closed at least through Friday because of flood damage to the building systems. The General Services Administration, which manages federal buildings, had not determined the extent of the damage, when it might be repaired or how repairs will cost, said spokesman Mike McGill.