HWL_action_guide_hires

15Stage 2 1. Visualize where in your community the line would be most visible and logical. 2. Identify recent flood or storm surge data, or investigate where riverbanks or lakeshore lines were historically. 3. Determine the boundaries of the flood zones or sea level rise and chart the line where you will navigate public space. 4. Identify key impact sites such as water treat- ment plants, subways, train tracks, electrical power plants, and tributaries flowing down toward larger water bodies. You’ll need to understand some of the science behind climate change, and tidal flow. Sea level rise is measured in vertical distance. In a coastal zone, a rise of just a few inches can cause salt water to push inland, changing fresh water to brackish water (a mixture of fresh and salt water) in some locations, and changing brackish water to salt water, in a process known as saltwater intrusion. As the sea levels increase or weather patterns change, the potential for flooding is even greater. Each city and area near a waterway will be impacted differently in terms of the level of inundation depending on a community’s ground elevation; sea level is relative. Questions to consider What types of utility infrastructure do you see below the line that would be impact the health, safety and mobility in your community? Where are the safety hubs or high ground facilities that your community can go to in a major flooding scenario? What type of neighborhood’s are in your community, different ethnic groups, age groups, and economic levels. Where do you live in relation to the line? How might it feel to live above the line? Below the line? ACTION STEPS STORM SURGE VS STORM TIDE Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tide. • It’s the change in the water level that is due to the presence of the storm • Since storm surge is a difference between water levels, it does not have a reference level Storm tide is the water level rise during a storm due to the combination of storm surge and the astronomical tide. • Since storm tide is the combination of surge and tide, it does require a reference level • A 15 ft. storm surge on top of a high tide that is 2 ft. above mean sea level produces a 17 ft. storm tide Source: National Oceanic and Atmospheric Administration

HWL_action_guide_hires

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