LYNNWOOD — A small stretch of Highway 99 in Lynnwood is the scene of a quiet, cordial conflict between wetland preservation and business promotion.

The disagreement involves two billboards, a 28-year-old document and a 99.8 percent discount on a city contract.

The city won’t cut back trees and bushes that are partially obscuring the two billboards, which are located in the urban wetland just south of 168th Street SW.

Under the city’s contract with Clear Channel, which owns the billboards, the growth of vegetation around the signs reduces the company’s annual rent for both signs to $5.

Normally, the tab would be $2,500.

The 1987 contract was negotiated between two parties no longer remotely involved in the matter. After 15 years, it automatically renewed.

The city inherited the contract when it bought the property from a Seattle real estate company in the fall of 1998. Lynnwood bought the property with the goal of protecting the wetland and improving flood management, said Jared Bond, the city’s environmental and surface water supervisor. A Seattle television company that owned the billboards then was purchased by Clear Channel in the early 2000s.

In the 1990s, the city also had planted trees in a grassy strip between the sidewalk and the road. That was done to meet state environmental rules for a project that widened Highway 99, Bond said.

Since then, the trees and the wetland have grown, making the billboards less visible, said Pam Guinn, branch president of the Washington division of Clear Channel Outdoor.

“Both of those things have added to the obstruction,” she said. “The sign is not entirely within view.”

Clear Channel operates nearly 200 billboards in Snohomish County, Guinn said. Most of those billboards are on private property, not public.

Meanwhile, the wetland provides the headwaters for the flood-prone Scriber Creek, which runs to Scriber Lake and continues toward Brier.

There hasn’t been any study showing the billboards have a negative effect on the healthy wetland, though their lights may affect wildlife, Bond said.

Clear Channel was billed $5 for the lease in 2013 and again in November, city documents show.

The contract says that the rent may be reduced to $5 if there is any obstruction of the signs.

The reduction lasts “so long as such obstruction continues,” the contract says.

The arrangement is unusual for Lynnwood, too, city spokeswoman Julie Moore said.

“I’m not aware of any long-term contracts of a similar nature,” she said. “This seems to be a unique situation.”

Neither Everett nor Marysville has contracts with businesses regarding billboards. Everett counts about 70 billboards in city limits, while Marysville has more than two dozen, officials said. Marysville “used to have one on city property through a lease to a billboard company, but that contract expired and we removed the billboard,” city administrator Gloria Hirashima said.

Lynnwood’s contract now runs through Jan. 6, 2017. If the city doesn’t take any action before Dec. 7, 2016, the contract automatically renews for another 15 years, Moore said.

The contract predated modern environmental regulation and wetland protection efforts, Bond said.

Lynnwood first started identifying and protecting critical areas in the early 1990s, he said. The city’s first ordinance to protect environmentally sensitive areas was passed in 1992.

Clear Channel’s request for some pruning prompted a “very friendly discussion,” Guinn said.

“It was all very cordial,” she said. “(City staff) really were unable to accommodate anything being changed.”

The city doesn’t do any vegetation management in the wetland, Bond said.

“We’re trying to just let it be a wetland, let the trees grow, let it do what it wants to do,” he said.

Rikki King: 425-339-3449; rking@heraldnet.com.