2 groups envision As the dredging of the Ala Wai Canal begins next week, some people already are looking past the yearlong cleanup with questions about the future.
a cleaner Ala Wai
They hope to maintain
water-cleaning efforts
following dredgingBy Diana Leone
dleone@starbulletin.com
Can the amount of silt that washes into the canal be reduced, so that costly dredging doesn't have to be done as often?
The equipment arrives
How it will be doneCan the water quality be improved so that canoe paddlers aren't getting serious infections from contact with the water?
Derek Chow, a project manager for the U.S. Army Corps of Engineers, says runoff into the canal can be reduced by a combination of methods that also will improve the health of Manoa and Palolo valley streams.
And Karen Ah Mai, executive director of the Ala Wai Watershed Association, believes that in her lifetime the canal could be restored to a fishable, swimmable quality.
"It was like that when I was a kid," Ah Mai recalls, and she wants it to be that way again for her grandchildren.
Chow's heading a $1.5 million study, jointly funded by the Corps and the state Department of Land and Natural Resources, of how they can reduce erosion "to a more natural level," improve flood control, better the Ala Wai Canal and revitalize the streams that feed it.
The feasibility study began in April 2001 and requires a report to Congress in March 2004.
Meanwhile, Ah Mai's organization is helping dozens of community groups, schools, clubs and individuals target their volunteer work in the watershed to make a difference in water quality.
The Ala Wai Watershed Association is supported by a $1.5 million grant from the Environmental Protection Agency, of which $500,000 is available for community projects that further its mission.
Chow and Ah Mai say their objectives are complimentary and the two efforts will blend.
"The state is doing what I consider to be maintenance dredging -- bringing back capacity of the canal to what it was constructed to be," Chow says of the $7.4 million job American Marine begins next week.
His work, he says, is "investigating ways to try and prevent the severity of the condition of the canal in the future."
Chow says even at this early stage, it is clear that a long-term remedy will not be cheap. A preliminary ballpark figure is more than $30 million. The soonest funds might be available would be 2006.
Chow says the Army Corps will use the Hawaiian ahupuaa concept -- managing the environment from the mountains to the reefs -- as a guide.
"Restoration can include revegetation with native plants, restoration of wetlands, sediment basins, and bioengineering stream channels," he says.
One of the options may be to divert runoff from the drainage area around the golf course to infuse the stagnant Kapahulu end of the canal with freshwater flow. All the options are modeled, at least in part, on what nature does to reduce erosion.
"We expect that these restoration features will benefit native fish and wildlife species and improve water quality," Chow says.
Ah Mai says that while the Army Corps is studying retrofits to cement-lined streambeds to slow rainwater enough to let the silt settle out, her organization will be organizing residents.
"There is a need for a tremendous public relations and education campaign to change attitudes about taking care of the watershed," Ah Mai says.
For example, she says, the Tantalus Community Association has spent countless hours pulling 200 dump trucks full of junk from nooks and crannies along Tantalus Drive. Dumpers apparently were residents of downhill urban Honolulu neighborhoods.
"The Tantalus people were astounded when I told them, 'If you don't work with your downstream neighbors, all your work will be for nothing,' " Ah Mai says. So she and Ramsay Taum, the association's other staffer, constantly are connecting neighborhood groups throughout the watershed, helping them see their common interest.
"When the Army Corps of Engineers gets funding for alternative sedimentation sites, the community will be already there," Ah Mai says.
Yesterday, Ala Wai Watershed Association volunteers began a stream monitoring project that they expect to continue over the coming year of the dredging, Ah Mai says.
At 22 locations on the Makiki, Manoa and Palolo streams and the Manoa-Palolo Confluence, the volunteers are measuring 10 factors, including water clarity, plant growth, streambed condition, water flow, bank erosion, habitat for native species and litter.
Chow says it is estimated that erosion of uninhabited conservation lands (one-third of the 16-square-mile Ala Wai watershed area) may account for up to half of the silt coming down the mountains.
But neighborhoods add garbage, motor oils, pesticides, fertilizers and other pollutants to the runoff.
"The magnitude of the problem becomes apparent when you consider that one-sixth of the entire state population -- 250,000 of 1.2 million people -- either resides in or passes through the Ala Wai watershed on any given day," Ah Mai says. "When you add the tourist population from Waikiki and the traffic generated by the visitors, the problem of human-induced pollution becomes very significant.
"The attitudes and behavior of residents and the public traveling in and out of the watershed are extremely important in the water quality of the Ala Wai Canal."
To reach the Ala Wai Watershed Association, call 955-7882. Dredging project information will be posted on its Web site: alawaiwatershed.org. BACK TO TOP
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Yes, there is a purpose to the large black piling installed in Ala Wai Harbor a few days ago. Ala Wai dredging project
set to begin next weekEquipment arrives for the
The scoop on the canal
canal's first cleansing in 24 yearsBy Diana Leone
dleone@starbulletin.comIt'll be the hitching post for the dump scows that over the next year will be ferrying about 167,811 cubic yards of muck from the bottom of the Ala Wai Canal to a deep sea burial.
It's the hope of many nearby residents and users of the canal that the cleansing, its first in 24 years, will be the start of a new era for the venerable canal that's supposed to keep Waikiki from flooding and provide a picture-perfect workout pool for canoe paddlers.
That's not been the case in recent years, when paddlers sometimes have to get out and carry canoes over shallow spots, risking infection from contact with the canal's polluted water.
Setup work for the $7.4 million contract began last week, and dredging probably will begin next week, slightly behind the projected start date of Tuesday, said Neil Williams, project manager for American Marine Corp.
The dump scows were to arrive from Oregon this weekend and must be outfitted with global positioning systems, so the Environmental Protection Agency can monitor their whereabouts.
Williams said this is the third-largest nonmilitary dredging to take place on Oahu in the past decade. He said work at the Missouri homeporting pier removed 350,000 cubic yards of dredge material, and work at Keehi Lagoon took 200,000 cubic yards.
When tugboats pushing the scows are passing through, boaters in the Ala Wai Harbor are asked to motor instead of sail, to give them greater control, Williams said, because the work boats "can't stop on a dime."
He expects an average of six barges to go to and from the dredge work site to the ocean dumping site each workday, Williams said. Anyone seeking the exact times of daily movements can tune in VHF radio frequencies 16 and 68.
Once a routine is established, Williams said, "Hopefully it will get to be as regular as a bus schedule."
In the canal, work plans call for canoe paddlers to be given a 50-foot passing lane around active work at all times except when a loaded or empty scow is being put into position.
The actual dredging work will be done by a crane with a clam-shell bucket mounted on a barge that will be anchored in place. The crane will scoop up the mud and put it in the dump scows.
All this will happen inside a work area of 150 feet by 600 feet that is to be surrounded by a silt curtain, a special impermeable fabric that extends 2 feet underwater from floats on the surface. The silt curtain's job is to keep stirred-up silt inside that work area.
The state Health Department has asked that American Marine make sure the turbidity (muddiness) of the water just outside the silt curtain be no more than 10 percent greater than that of undisturbed canal water 50 feet away, Williams said.
The state Health Department's Clean Water Branch will be monitoring the company's compliance with periodic site visits and daily water-quality checks, said Andy Monden, DLNR chief engineer.
The dump scows are watertight, so no dredge material should be released from them until they dump their loads at the EPA-approved site. Oahu's only approved site is 3.8 miles south of the Honolulu Airport reef runway, in waters of 1,300 to 1,500 feet.
Ala Wai Canal water will not be tested for contaminants during the dredging, Monden said, because earlier sampling determined 99 percent of dredge material is within allowable EPA pollution limits for ocean dumping, said Monden.
More troublesome to get rid of will be 1,815 cubic yards of more polluted material (1 percent of the total) in the Kapahulu end of the canal, Monden said. American Marine is responsible for offering a proposal on how it will handle that material and will hold a public meeting to explain its plan before that portion of the work is done.
A proposal to solidify the polluted dredge material and use it to fill in low spots in the airport reef runway has been questioned by some who fear that method might allow the pollutants to escape in the future.
Sen. Suzanne Chun-Oakland (D, Kalihi-Palama) has searched for alternative ways to dispose of Kapahulu-end material and even suggested there may be better ways to deal with the bulk of the dredge material than dumping it in the ocean.
"I believe my community's preference would be to have the dredge material naturally remediated through bioremediation," Chun-Oakland said. Though she failed to get $400,000 from the 2002 Legislature for a study of using plants to remove toxins from soil, Chun-Oakland said she has not given up.
"New and not-so-new technologies need to be explored in dealing with contaminated materials," she urged. "We should test various native Hawaiian plants and their ability to clean the soil before utilizing it again. We do need to get away from disposing of anything in the ocean if we can."
Rep. Mindy Jaffe (R, Diamond Head-Kapahulu) also is among lawmakers with concerns about placement of the dredge material, but she is clear about the need for dredging.
"We've let it go too long. It's supposed to be dredged every 10 years and it's been way longer," she said. "This has to be done."
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The scoop on the Ala Wai
Canal completed: 1927.
GRAPHIC BY KIP AOKI / KAOKI@STARBULLETIN.COM
Click image for larger version (304K).
Last dredged: 1978.
Dimensions: From Ala Moana to McCully bridges, 150 feet wide; from McCully to Manoa-Palolo Confluence, 250 feet wide; by Kapahulu Library, about 150 feet wide. Two miles long.
Drainage area for Ala Wai Canal: 16 square miles, of which one-third is conservation land and two-thirds is urban. Areas draining into the Ala Wai Canal are Manoa, Palolo, Makiki, Punchbowl, Tantalus, Moiliili, St. Louis Heights, Kaimuki, Kapahulu, Diamond Head, Ala Moana, Kakaako, McCully and Waikiki.
Streams feeding the Ala Wai: Manoa, Makiki, Palolo streams and their tributaries.
Annual sediment load into canal: About 8,000 to 10,000 cubic yards
Amount of dredge material to be removed: 169,626 cubic yards, or enough to cover a football field to a depth of 94.5 feet high.
Dredging work hours : 6:30 a.m. to 10:30 p.m. on weekdays.
Pollutants in the canal: Coliform bacteria (indicator of fecal matter); nutrients (fertilizers); sediment; pesticides; litter and garbage.
Pollutants that need special handling: Chlordane and lead, in the Kapahulu end of the canal.
Questions about the dredging?
American Marine Corp., job contractor: 545-5190State Department of Land & Natural Resources, public information office: 587-0330
Movement of boats: VHF channels 16 and 68.
