 The flooding was caused by Irene's rains coupled with the basin having poor drainage in the rugged, hilly land with steep slopes.As of the census of 2010, 3,154 people resided in Chester, with 1,793 housing units.In 2010, Chester had 510 residents 14 years old and younger; 205 15 to 19; 277 20 to 29; 298 ages 30 to 39; and 418 ages 40 to 49.