Little Cypress Creek is usually considered the "22nd Watershed" within Harris County, although it is actually a subwatershed of the major Cypress Creek watershed. The Little Cypress Creek watershed encompasses a mostly rural, undeveloped area of northwest Harris County. Based on the 2010 U.S. Census, the estimated population of the Little Cypress Creek watershed is 28,879.
Little Cypress Creek is not always delineated separately on Harris County Flood Control District maps. As far back as 1944, however, when the Flood Control District’s unique internal unit numbering system was devised, it was given its own watershed letter – “L” – to help identify its associated tributaries and flood damage reduction projects. Cypress Creek is designated with the letter “K.”
Little Cypress Creek comprises more than 15% of the larger Cypress Creek watershed, with a drainage area of about 50 square miles.