The Los Angeles River is a 51-mile long waterway that flows through the city of Los Angeles, California. Originally a natural river, it has been heavily modified with concrete channels to control flooding and manage water flow. The river's watershed covers about 834 square miles, draining into the Pacific Ocean. Despite its urban setting, the Los Angeles River supports various ecosystems and wildlife. Efforts are underway to restore sections of the river to enhance its natural habitat and provide recreational opportunities for residents. The river also plays a role in the city's water management and flood control systems.