Winter is coming, the rain has started and those living near the Dungeness River should be prepared for potential flood hazards, according to Clallam County officials.
Clallam County environmental planners and the Dungeness River Flood Hazard Planning Team are hosting an informational open house Nov. 12 to provide background on flooding along the Dungeness River and how residents can prepare for flood-related emergencies.
The meeting will feature maps, photos of flooding along the river and emergency preparedness materials. Attendees also will have the chance to win a NOAA all-hazard weather radio that can be used during flood watches and warnings.
Flooding along the river might not be what most imagine a flood to look like, said event organizer Sam Gibboney, with ISE Consultants, who indicated there would be discussions on the river’s flood plains as well as possible river channel migration hazard areas.
The 100-year flood plain represents the area near the river that would be flooded during a 100-year storm. Contrary to popular belief, a 100-year storm is not a storm that occurs once every 100 years. Rather, it is the storm, as measured by the amount of precipitation, that has a 1 percent chance of occurring in any given year.
In contrast, the channel migration zone includes areas that have the potential to experience channel movement. Rivers such as the Dungeness can change course, often abruptly, and the channel can erode banks or suddenly occupy relic channels.
Emergency preparedness officials want people to know floods on the Dungeness can happen quickly. In addition, it is important to understand that the flood elevation in the river can lag behind the actual precipitation. So, just because the rain has stopped doesn’t mean the danger has passed.
People who live or own property along the Dungeness are encouraged to attend the meeting. Organizers will have information and handouts for emergency planning that can be used before, during and after a flood.
Flood plan
The general purpose of the meeting is to prepare nearby residents for floods. But it is also a step in the direction the county is taking to create an updated flood control plan.
The aim of the plan and its update is to prevent loss of life and property from flooding, integrate flood hazard reduction with efforts to preserve and restore river habitat, maintain the varied uses of the river and to provide a plan for future management, according to county environmental planner Hannah Merrill.
Merrill gave one example of river restoration, moving dikes farther from the river.
"When dikes were put in along part of the river, silt began to build up so those dikes are no longer as effective as they used to be because they caused the river to gain elevation over time, collecting the erosion from upstream," she said.
The county has a dike setback plan but moving them back will require additional funding and land acquisition. Once the dikes are set farther away from the river, its channels will be able to meander in a wider plane, reducing the risk of flooding.
Another change may be to reformulate how the county improves roads along the river’s edge. If a road near the river is in a hazardous spot and the Public Works Department has it scheduled for improvement, the plan might require those improvements to include a slight redirection to get the road out of the hazardous area.
"The plan will not require roads to be moved right away and it would not force anyone out of their homes but it will provide information to us at the county and homeowners in general of threats the river may bring and what we can do to reduce those hazards," Merrill said, indicating the plan would provide recommendations and not requirements.
The county is operating under a 1990 flood management plan. The plan is being updated because new information has been made available in recent studies of the river’s historic migration and new state regulations must be adopted.
The plan is in its early stages of formation. The meeting will not cover the plan but rather some of the new information its update will be based on. A separate public meeting will be set to review the flood plan once the county has a draft ready for review, which may be in the spring of 2009.
For more information about the meeting or if you have questions, call Hannah Merrill at Clallam County at 417-2563.
Clallam County and the Dungeness River Flood Hazard Planning Team are hosting an open house, drop-in style meeting from 4-7 p.m. Wednesday, Nov. 12, at the Sequim Library, 630 N. Sequim Ave., to identify potential flood hazards in and around the Dungeness River and aid those in its path to prepare for any potential emergencies.
