Pueblo Watershed

This is part 3 of a 5 part series of results from our water monitoring lab. If you haven’t read our watershed report, head over here and check it out. In this third part, we are going to take a look at the Pueblo watershed.


The Pueblo Watershed is San Diego County’s smallest, and most urbanized, watershed. The roughly 60 square mile watershed drains into San Diego Bay. The Pueblo Watershed runs through the heart of the City of San Diego and it’s boundaries overlap with portions of the Lemon Grove, La Mesa, and National City. The main creek running through the watershed is Chollas Creek, which has two main forks that run through the most densely populated part of the City. As a result, we have altered and lost much of it’s native habitat. Chollas Creek is straightened, channelized, or driven underground in various places.

The extensive hydromodification of the creek has resulted in the loss of almost all of the natural habitat associated with the creek. In fact, the creek is so altered that nearby residents often don’t know there is a river flowing in their neighborhood. Only the tributary canyons offer some habitat for animals like the threatened Cactus Wren.Pueblo_Trash_Credit__NASSCO

In general, our monitoring program found the creek has high levels of ammonia, phosphorus, and trash. During the rainy season, these pollutants are carried from inland sources into the creek and out to the bay. The nutrients contribute to an excess of of algae growing in the creek and the trash contributes to our marine debris problem.


Fortunately there are a number of organizations trying to reverse this declining trend. Groundwork San Diego, Chollas Creek; The Jacobs Center for Neighborhood Innovation; and San Diego Canyonlands are working to restore the watershed’s natural hydrology and habitat.  The Environmental Health Coalition is working hard on environmental justice issues in the area which will help abate some of the problems the area’s residents face by living so close to industrial and transportation centers.

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