Nearly a decade ago, water rushing down Manoa Stream jumped the banks and surged downhill at the edge of the University of Hawaii, slamming "like a tsunami" into the main campus library, said Lynn Davis, who heads its preservation department.

Hamilton Library’s basement quickly filled with water, damaging thousands of materials.

Staff members quickly gathered up many irreplaceable items such as rare Hawaii and Pacific region maps and aerial photographs, which would later be frozen to prevent mold growth.

Today, while restoration efforts are still wrapping up, Davis is prepping for two exhibits that commemorate the 10-year anniversary of the Oct. 30, 2004, flood. One details salvaging and the other showcases recovered rare maps.

Rather than dwell on the sudden drenching and the trauma tied to it, the exhibits, which will be on display in October at the library, aim to focus on "what we’ve accomplished," Davis said.

Among the library items saved: Some57,700 maps, including several thousand world maps made during World War II; nearly 76,800 aerial photos; and about 430 Pineapple Research Institute books containing documents with information pertaining to the development of the pineapple industry and crop varieties.

Few copies of those documents existed, Davis said, adding, "If this was lost, it’d be really hard to replace."

The flooding, which swamped Manoa Valley with more than 10 inches of rain in 24 hours, caused an estimated $81 million in damage to the UH-Manoa campus. Elsewhere in the valley, it caused extensive damage to homes and schools.

State Civil Defense estimated nearly $71 million in damage to state property, according to a 2006 U.S. Army Corps of Engineers study of the flood.

At Noelani Elementary School, which also edges Manoa Stream, flood waters entered the administration building through the principal’s office door, soaking the office with 3 feet of water.

"The campus was a total mess because of all the debris," said then-Principal Fred Yoshinaga. "You had live fish. You had just a whole bunch of things."

The parking lot was covered by a foot of mud.

Yoshinaga, now principal of Fern Elementary School, said the walls in Noelani’s office had to be taken down to dry out. In the immediate aftermath of the flooding, however, no additional mitigation mechanisms were put in place at the Noelani campus.

"The only thing we did was we secured more sandbags" to keep in reserve to fend off future flooding, he said.

Post-flooding mitigation efforts at UH-Manoa’s Hamilton Library have included a six-year basement reconstruction and increased underground drainage.

On a larger scale, various city, state and federal government offices and agencies are spearheading the Ala Wai Canal Project, which aims to reduce flood hazards and restore flood-damaged ecosystems in the Ala Wai watershed, which extends from the crest of the Koolau Mountains down to the nearshore waters and includes Manoa, Makiki, Palolo, McCully, Kapahulu, Moiliili and Waikiki.

A draft environmental impact statement for the project, which took shape after the 2004 flooding, is expected to be released next year, said Athline Clark, a project manager for the U.S. Army Corps of Engineers.

In addition, the state Department of Land and Natural Resources is coordinating with the city and Army Corps of Engineers to modify the area under Manoa Stream’s bridge on Woodlawn Drive, situated near UH faculty housing and Manoa Marketplace, as well as about 900 feet downstream where flood waters jumped the stream’s banks and ran toward Noelani Elementary.

Plans are in the works to create a drop structure under the bridge that steps up velocity at the site, to flush out sediment that would normally build up. Downstream, DLNR plans to smooth out the channel and line a section of it with concrete to improve water flow. Construction is expected to get underway next year.

A bit farther downstream, at the UH-Manoa campus, another project is looking at further expanding drainage infrastructure and creating "bioswales" — drainage courses with gently sloped sides and filled with vegetation that removes silt and pollution from surface runoff.