Flood
Flooding is the most common hazard occurring in Kitsap County. Heavy, prolonged rain in the fall, winter or spring months often result in saturated ground and high stream flows. Due to ground saturation, structures on Bainbridge Island located in low-lying areas tend to flood during prolonged periods of rain. Wind-driven tidal flooding is also possible along the inland waters. Flooding is due to runoff, ground saturation, or tidal flooding. Floods may result in loss of life as well as damage to residences, business establishments, public buildings, roads and bridges, utilities, agricultural land, fish and shellfish habitats, stream banks and flood control structures.
King Tides may also cause flooding on Bainbridge Island. King tides bring unusually high-water levels, and they can cause local tidal flooding. Over time, sea level rise is raising the height of tidal systems. Average daily water levels are rising along with the oceans. As a result, high tides are reaching higher and extending further inland than in the past. King tides preview how sea level rise will affect coastal places. As time goes by, the water level reached now during a king tide will be the water level reached at high tide on an average day.
Flooding can obstruct access to roadways. If possible, move vehicles to higher ground before the King Tides begin and wash your vehicle down with fresh water after driving through salt water. Elevate anything at home, such as paint cans, automotive supplies, lawn chemicals, etc. that could float away in the water and cause water quality degradation.
Additionally, follow these safety precautions:
- Do not walk through flood water if possible. It is a health hazard.
- If you do need to walk through flood waters follow good hygiene practices and wash your hands, clothes, and pets after.
- Do not drive through flooded areas - it is dangerous and can damage your vehicle. Find an alternative route. Remember: Turn Around, Don’t Drown.
- Boaters should be aware that high tides cause lower clearance under bridges - check the tide before leaving the dock.
Preparedness Resources
- https://www.floodsmart.gov/first-prepare-flooding
- https://www.redcross.org/get-help/how-to-prepare-for-emergencies/types-of-emergencies/flood.html
- https://www.fema.gov/sites/default/files/2020-07/how2009_anchor_tanks_cylinders.pdf
- https://www.kitsapdem.com/kc-coastal-flooding/
- https://kitsappublichealth.org/information/files/kphdflooding_storms_factsheet.pdf
Bainbridge Island has the largest number of buildings in the SFHA (1-percent-annual-chance flood zone) and has the highest loss ratio which compares the losses due to flooding to the overall building value within Kitsap County. Not all of the buildings within the floodplain experience damage due to level of flooding as well as current floodplain regulations.
The most current 1 percent (formerly called 100 year) flood data is available here.