The rapid economic growth of the People’s Republic of China (PRC) has depended in part on reservoirs, which have facilitated flood control, irrigation, hydropower generation, and water supply. These reservoirs are grouped by the country into three safety classes. Class III, comprising 37,032 reservoirs or 43% of the total as of end−2006, are the least safe.
Many cities and industrial centers in the People’s Republic of China (PRC) are on or near major rivers, which puts a high proportion of the country's economic activity at risk from periodic floods. Major flooding and the poor drainage that contributes to it constitute the most common and severe form of natural hazard in the PRC.