A backyard pool, long a refuge for the family during hot summers, outgrows its usefulness. A major flood in 2013 did its own share of damage. How do you combine the two issues? By using the former pool shell to create a massive dry-well for future floodproofing and a sunken patio for daytime and evening enjoyment. A pergola with moveable vents creates cover or shade, with light in the evening provided by the gas fire pit. Stairs double as seating, and plantings keep the feeling cozy.