Water Quality Index Score: 56, Marginal
- Chollas River sites often had very high phosphorus and ammonia
- Ph and nitrate levels were the only water quality indicators that were not of concern
- Volunteers found and removed lots of trash from our sampling sites in this watershed
As this watershed is home to Chollas Creek, one of San Diego’s most urban rivers, these results aren’t unexpected. The high phosphorous and ammonia levels in this watershed are a common result of urban runoff, when rain washes pollutants, like lawn fertilizers and pesticides, down our storm drains and into our rivers and streams.
This creek is also infamous for drying up, so our dataset is missing many samples throughout the year. In fact, more sites went dry this year than any other year in Coastkeeper’s recent sampling history here. All signs point toward poorer water quality than shown with the samples that we could collect. With more flow and more samples, this watershed probably would have earned a Poor Water Quality Index Score.