Living on the island of Oahu brings unique stormwater challenges to Iwalani Sato, community relations specialist in stormwater management for the City and County of Honolulu, Hawaii.

 

Most Hawaiian watersheds are small, and streams are short and steep with low but flashy flows. The island also has distinct weather. On the windward side of the Koolau Mountains, heavy rains create high-volume, high-velocity flows in the streams and upland areas. On the leeward side, the southwestern coastal areas are dry. The differences occur over a horizontal distance of a mile.

 

“The mountains are high enough to have a water cycle,” says Sato, whose Storm Water Quality Branch is within the Division on Environmental Quality under the Department of Environmental Services. “That’s important, because we need as much stormwater as possible to soak in and replenish the aquifer. Our ongoing challenge is convincing communities that minimizing polluted runoff is essential to water quality.”

 

Sato and her team embrace how water is tied to the Hawaiian culture as part of former mayor Mufi Hannemann’s 21st Century Ahupua’a (watershed) initiative. The initiative involves learning the sophisticated resource management system that supported Polynesian ancestors almost as numerous as Honolulu residents today.

Adopt-A-Block and Adopt-A-Stream programs preserve the legacy through education, while less traditional strategies attract and inspire new generations to protect Hawaii’s water resources from mauka to makai (mountain to sea).

 

Environmental stewardship

The stormwater programs balance ambitious MS4 permit goals against realistic neighborhood improvements. By breaking polluted runoff into controllable, simple processes in and around homes, the team guides citizens and then empowers them to make a difference.

 

For example, illegal trash dumps remain a key problem. Residents who complained the loudest about them found an opportunity to act by volunteering in the Adopt-A-Block or Adopt-A-Stream programs. “By keeping monitoring units small — a block or two — volunteers can quickly assess improvement potentials,” says Sato. “These are rapid-response projects that accomplish results within months.”

 

Volunteers select two pollutants. Most pick trash and nutrients or sediments, then walk their blocks reporting hot spots. When Sato receives a call about a clogged catch basin, she immediately alerts the Department of Facility Maintenance, which sends a crew to clear the obstruction.

 

“We want volunteers and residents to see prompt action at the municipal level,” she says. “Our investigators then identify and control the source of the pollution.”

Modifying behavior is trickier, since volunteers find it difficult to confront residents who display poor neighborhood housekeeping habits. Instead, Sato recommends that volunteers invite the people to a cleanup event. The softer approach often achieves voluntary compliance and a sense of stewardship.

 

Aquatic detectives

The Adopt-A-Stream program requires basic observation skills. To assess general water quality, volunteers look for flows leading to storm drains on dry days and check for water that is milky or soapy, has an oil sheen, or has an odor.

 

“Taking action on nutrients and sediment moves us into more sophisticated stewardship practices in the home, yard, and workplace,” says Sato. “Usually, our more sophisticated neighborhoods also do the chemical or biological assessments.” Volunteers receive Adopt-A-Block or Adopt-A-Stream T-shirts.

 

Children have their own water-quality education program. During World Water Monitoring Day in September, Sato partners with Washington Middle School, Waipahu High School, and other agencies to teach students in grades 8-10 how to collect water samples and measure water quality using indicators such as pH, dissolved oxygen, temperature, turbidity, nitrate, phosphate and conductivity.

 

By learning more about neighborhood source control, they learn how their activities at home affect storm drains and downstream waters. “The basic idea is to create an active group of Adopt-A-Stream and Adopt-A-Block volunteers to share clean water stewardship information with their neighborhood peers,” says Sato.

 

“When they begin to understand the range of homeowner behaviors that contribute to polluted runoff, they can encourage positive actions, such as picking up litter, sweeping sidewalks and gutters, mulching, composting, and planting to prevent polluted stormwater runoff.”

 

In 2007, the department developed a Teen Video Contest as part of Earth Month in April. The team worked with video specialists from eight high schools on the leeward coast, where trash is a major issue. Workshops taught the students about the problem and showed them solutions. “We wanted a 30- second public service announcement that motivated people to act,” says Sato.

 

The schools submitted 37 entries in four categories: erosion control, nutrients, recycling and community action. Tied for first place were Our Waters by Desiree Agngarayngay of Campbell High School; and Keep Trash in the Can by Susan Bowyer, Hokulani Matutino, and Kiana Bersamin of Waianae Intermediate School.

 

The videos were broadcast on major TV stations and posted on YouTube under the Clean Water Honolulu account. Scott Williams, president of Lex Brodie’s Tire and Service Centers, and Troy Ogasawara, president of Geotech Solutions Inc. in Waipahu, donated computers and digital cameras to the two schools. They will sponsor the contest again when it returns in 2011.

 

Environmental partnerships

The department also has an industrial-commercial pollution prevention program, emphasizing businesses that excel in best management practices and are active community members. Lex Brodie’s, Geotech, and Hui Ku Maoli Ola Nursery head the good business neighbor roster.

 

Williams partnered with Sato to develop fact sheets on BMPs for the auto repair industry and for people changing their own motor oil. Ogasawara donates and installs geotextile fabric, erosion-control matting, and fiber rolls for Adopt-A-Stream demonstration sites in Waimanalo and Kaneohe.

 

Nursery owners Rick Kapon-owaiwaiola Barboza and Matt Kapaliku Schirman helped Sato develop information for homeowners interested in natural landscaping and using native plants to control erosion. Besides holding workshops at the nursery, the men take part in stream restorations.

 

“Our biggest multiple partnership success story is Kapakahi Stream,” says Sato. That 280-acre impaired watershed passes through 70-acre Pouhala Marsh, the largest remaining wetland habitat in Pearl Harbor and a crucial resource for endangered native plants and animals.

 

No dump here

Tim Steinberger, environmental services director, recalls that at one time the city considered using the area for a dump. Instead, the city built the Waipahu Convenience Center next to Kapakahi Stream. Residents are restricted to two loads of trash per day, and they often dump illegally in the stream after hours. Bulky items range from mattresses and furniture to chicken cages, automotive parts and appliances.

 

“Since 2005, sophomores from Waipahu High School, one of our partners, have assisted in cleanup and monitored water quality,” says Sato. Another partner, the Hawaii Nature Center, developed a third-grade wetland education unit ending in a field trip to the marsh. The nature center also sponsors community service days.

 

Meanwhile, the City and County of Honolulu upgraded 2,364 feet of 10-inch concrete sewer line with12-inch PVC pipe. The old line was a point source for excess nutrients, and root intrusion caused blockages. The Department of Facility Maintenance changed its roadside weed management from minimal chemical applications to mowing.

 

The Department of Land and Natural Resources, Division of Forestry and Wildlife, U.S. Fish and Wildlife, and personnel from the Naval Station at Pearl Harbor erected a fence around the watershed, removed 66,000 cubic yards of landfill in eight acres, and built a quarter-mile-long boardwalk with interpretive stops. Today, the area has returned to a functioning wetland ecosystem.

 

Getting there

Only 200 of the island’s 2,559 outfalls are coastal. The Road Maintenance Division maintains the stormwater conveyance system but works closely with Sato and the Refuse Division to identify and mon-itor illicit stormwater discharges and bulky-item hot spots in city channels, streams and roadways.

 

The city retrofits storm drains with separators, mounts filter traps in catch basins, and installs litter booms in channels or streams.

 

In 2003, the city initiated a pilot project to evaluate four types of manufactured inlet filters for ease of installation, overall costs, performance and maintenance. The study concluded in 2006. Since then, the city has retrofitted more than 200 catch basins with basket filters from Bio Clean Environmental Services, and 100 more will be added.

 

Sato believes that controlling nonpoint source pollution will be the island’s greatest stormwater challenge for the next 30 years or more. “I can identify progress in some areas, then turn around and still see chickens in streams beside diapers and television sets,” she says. “These projects are not one-shot deals. We’re in it for the long haul, but if we do our jobs properly, the next generation will carry on the mission.”