MEADOWDALE — Carlin McKinley has seen the aftermath of mudslides in Meadowdale Beach Park, which runs through a gulch downhill from her house.

The washouts in the wooded preserve give her reason to worry about a development proposed about 200 feet above her, on the same steep hillside of second-growth forest.

Seabrook Heights would include 70 homes on 13 acres, nearly a third of which is off-limits to construction. To make way for the houses, developer West View Properties wants to cut down hundreds of large trees.

The new houses and the loss of trees, McKinley fears, would add to water runoff flowing toward her and the park. If that happens, it’s bound to increase the risk of landslides.

“It’s a very unstable ravine,” she said. “To do anything at the top is crazy.”

Landslide concerns dogged the Seabrook project long before a March 22 mudslide killed 43 people in Oso. Though no one is suggesting anything on the order of the Oso slide’s mile-long debris field, the project in the Meadowdale area continues to trouble some experts and government leaders.

Slide risks were a major reason the Snohomish County Council awarded Lynnwood $5 million in conservation futures grants last year to buy the Seabrook property.

Everett-based West View Properties originally suggested it would consider selling the land. City officials said their $5.25 million offer has gone unanswered. A deadline passed a week ago. The proposed sale price is more than double the property’s assessed value for 2014.

“We’re taking their silence as a rejection of our offer,” said Jared Bond, the city’s environmental and surface water supervisor.

West View’s president, David Beck, did not return calls for comment.

For now, plans to build Seabrook Heights are moving forward.

The project would take shape on land along Fisher Road, near where it splits from Norma Beach Road. It’s mostly woods now marked by “no dumping” signs.

County planners are satisfied the project meets all drainage and steep-slope requirements in the county code, permitting manager Tom Rowe said. After the Oso catastrophe, they required the developer to submit a second opinion this summer from a geotechnical engineer about slope stability.

That’s something they’ve done with at least three developments awaiting approval in areas with landslide risks.

“Based on our experience with Oso, we’ve gone back to take a second look at those projects,” Rowe said.

A public works geotechnical engineer provided the planning department with a peer review of the latest plans, Rowe said. Staff expect to issue a so-called mitigated determination of significance for Seabrook later this month. That means they’re ready to approve the application, subject to requirements that, in this case, don’t involve water runoff or landslides.

McKinley has two grown children and works in real estate. She said she made an offer on her house in the late 1990s within an hour of seeing it.

The Seabrook Heights proposal application interrupted her sense of peace when it surfaced in 2005. She successfully appealed the project to the county hearing examiner in 2009. Barbara Dykes, the examiner at the time, took county planners to task, accusing them of failing to take a critical look at what the developer’s engineering consultant said about nearby slopes.

“From the testimony, it is clear that there was no review of the geotechnical report by PDS (Planning and Development Services) at all,” Dykes wrote in her decision. “… In essence, there was no review done by the department under the landslide hazard provisions of the code.”

Dykes sent the project back to address drainage and geotechnical concerns.

The County Council upheld the examiner’s decision when West View appealed.

County planners bristle at the former hearing examiner’s attack on their work.

“That was her opinion,” Rowe said. “We thought there was a substantial review done on that.”

The original plan included 69 homes. West View re-submitted plans in 2010 with a total of 70 homes, plus extra measures to lessen water runoff.

McKinley and her neighbors would prefer the project isn’t built at all. At the very least, they would like to see a robust environmental study, which they believe will back up everything they’re saying.

They have a strong ally in the city of Lynnwood, which has bought up 77 acres around Snohomish County’s Meadowdale Beach Park for conservation. About a third of that city property lies immediately downhill from the proposed development. The area is outside Lynnwood’s city limit but in a potential annexation area.

“Our primary concern is definitely slope stability,” Bond said. “We are downslope. Our property could be seriously damaged from this.”

Lynnwood and the nonprofit Brackett’s Landing Foundation also want to protect Lund’s Gulch Creek, which runs through the county park. They don’t want landslides or sediment to harm populations of cutthroat trout, coho and chum salmon that live there.

Historical maps show that shallow landslides are common along the Puget Sound bluffs, including in the Meadowdale area, said Timothy Walsh, the state Department of Natural Resources’ chief hazards geologist.

Soils in the Meadowdale area are similar to the glacial deposits found at Hazel, the hill that gave way in Oso, Walsh said. The potential for massive slides are much less, though. The failure plane, the point where the land is likely to give way, is much closer to the ground’s surface in areas near Puget Sound. The groundwater conditions are different as well.

That typically leads to shallow slides near the Puget Sound shoreline, starting at a depth of 5 or 10 feet, Walsh said.

The mass of these slides can grow, however, as they add material heading downhill.

People who live in the area relate anecdotes that mesh with Walsh’s overview.

McKinley said at least three slides have hit the Meadowdale Beach Park during the 15 years she’s owned her secluded property, which is close enough to the park to hear hiker’s voices. Walk the park’s mile-long trail down to the beach, and you’ll see some of the evidence in the form of huge ruts and washouts. One slide, in late 2007, shut down the park for nine months.

In the Norma Beach neighborhood west of McKinley’s house, a slide during heavy rains in March 2011 left one house uninhabitable. Rich Lord felt lucky to escape after trees and brush crashed through his roof.

“We were worried about the people around us,” Lord said at the time. “This isn’t a game. You could die in this stuff.”

Building regulations in landslide-hazard areas have received extra attention since the Oso disaster.

The County Council this spring considered imposing a building moratorium extending a half mile from potentially dangerous slopes. They abandoned the idea after discovering that such a buffer would cover most of the county, with the few exceptions dominated by flood-prone river valleys.

Council Chairman Dave Somers, who spearheaded the effort, later proposed controversial measures to try to protect people and property. Ideas included recording landslide dangers on property titles to warn future owners of risks, expanding the areas around steep slopes that require a geotechnical study before new construction, and making those engineering studies adhere to more rigorous standards.

McKinley and her neighbors testified about the Seabrook property during the council hearing.

Somers’ proposals failed to gain any traction with his council colleagues, and they never even received a public discussion. The council did impose a building ban in the immediate Oso slide area.

An expert commission assembled by Gov. Jay Inslee and County Executive John Lovick to examine the response to the Oso disaster is looking at land-use regulations in slide zones, among other issues. A report is due in December.

McKinley said she’s been unable to mow her yard since 2010 because it’s become too wet. She blames it on trees that have already been cut down uphill from her.

The landscape around her house could become much wetter if hundreds of trees are cut down for the Seabrook development, said Christina Bandaragoda, a hydrologist and University of Washington researcher who has consulted for McKinley.

That’s in large part because of a process called evapotranspiration — in which trees intercept and evaporate moisture before it reaches the ground and use the water (transpiration) before it infiltrates below the root system.

Forests can intercept 10 to 70 percent of rainfall depending on tree species, time of year, and precipitation rates, Bandaragoda said.

In her opinion, county decision-makers lack adequate information to reach a sound conclusion about how the developer’s project would change the amount of water moving through the area.

There’s nowhere to put stormwater runoff other than on McKinley’s land, she said, and “It’s illegal to dump stormwater on someone else’s property.”

There’s also scientific value in preserving the area around the county park, she believes.

“This is a wonderful example of how the coastal Puget Sound forested wetland ecosystem should function,” she said. “It’s not known how forested wetland ecosystems functioned historically.”

McKinley said she’s determined to keep fighting the proposed development, though it’s already taken up all of her savings.

“My stress level is unbelievable,” she said. “Here’s this house I love and I could lose it at any moment.”

Noah Haglund: 425-339-3465; nhaglund@heraldnet.com. Twitter: @NWhaglund.