The Los Angeles River Watershed is approximately 834 square miles and home to a whopping 9 million people living among 43 cities (LACDPW). The Los Angeles River itself runs 52 miles from its headwaters in Canoga Park to the Pacific Ocean. As the river winds, it crosses multiple habitats and urban areas, meeting people and picking up pollutants on its way. It is imperative we understand the land use, climate, and geology of the whole LA River Watershed system as we consider how to make it more sustainable and healthy in the future.
Topography of the LA River Watershed
The topography of the Los Angeles River Watershed is unique because it encompassess both mountain ranges and the coast. The river runs from the mountains, down the rich, nutritious alluvial plain of the LA Basin, and out into the Pacific Ocean. The highest point in the LA River Watershed is over 7,000 feet in the northwest San Gabriel Mountains, dropping down to sea level at the Pacific Ocean. This drastic change in elevation over a relatively short distance makes the LA River speedy! The river drops an average of 31 feet per mile! Compare this to the 2,348-mile long Mississippi which only drops 1 foot per mile, and you’ll quickly understand how speedy the LA River is.
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