What is a arroyos flood?

An arroyo is a Spanish Word translated as brook, and also called a wash is usually a dry creek or stream bed-gulch that temporarily or seasonally fills and flows after sufficient rain. Wadi is a similar term in Africa. In Spain, a rambla has a similar meaning to arroyo. In Hispanic America any small river might be called arroyo, even if it flows continually all year and is never dry.