Urban Runoff (42)
In 2014: Looks like San Diego's drought affects more than water quantity—and we have the data to show it.
We proudly announce the results of our 2014 Water Quality Monitoring efforts, and a few key takeaways from this year's data. One of the most striking trends we see is that our third consecutive year of drought (7.77' total rainfall in 2014 compared to the 10.34" average) has likely contributed to inland water quality issues.
One issue likely related to drought conditions that our 2014 data revealed is low dissolved oxygen concentrations. Turns out that 30 percent of our inland water quality samples that we gathered from across the county measured below healthy levels. Sadly, when dissolved oxygen measurements reach levels this low, aquatic life dies. In April 2014, we even ran across a fish kill in San Luis Rey from just this.
Another trend related to low water levels that shows in our 2014 numbers is that fecal indicator bacteria levels (especially Enterococcus) were a concern across all watersheds. Of our samples in 2014, 57 percent of the Enterococcus samples exceeded healthy standards, and eight of nine watersheds scored marginal or poor for their E. coli scores.
What does this mean?
Enterococcus indicates whether water conditions are safe to swim, most commonly used to measure healthy conditions of salt water. Since all of our inland waterways empty to the ocean, it's not a good sign that we're measuring so much Enterococcus in our fresh waters. If you don't know, this means that the water has pollutants in it that can cause staph infection, ear aches, stomach issues, rashes, eye infections, cysts, and others—just to name a few.
To be accurate, there can always be an amount of Enterococcus in our water due to natural causes (aka bird poo), and those may not cause human health impacts. But the levels in our data are so high, we have major concerns. To illustrate the degree to which this is a problem, our December sampling event took place on the day after a heavy rain, and every single sample collected far exceeded healthy levels acceptable for Enterococcus and E. coli. This is why the County's Department of Environmental Health closes the beaches countywide after it rains--water quality is extremely poor.
These sort of data sets also raise a question that we can't answer: Is the drought reducing water levels so much that shallow, slow-moving and warm streams create a breeding ground for Enterococcus and E. coli? More so than any other recent year, a lot of our sites even dried up in 2014 so that we couldn't gather samples. But given our analysis and the increase in water quality impacts shown by fecal indicator bacteria, we're curious to explore this question. Unfortunately, the data that we collect can't help us answer this question.
As you can see in the countywide map, Water Quality Index Scores grouped the map's color-coding into three sections: fair scores in the north, marginal in the middle and poor in the south. We're not surprised to see this as we think that these groupings of scores relate to the various land-use types and density of development within the watersheds. The north has more open space and agriculture, the middle has more density and developed land area and the south struggles with cross-border water quality management challenges.
We encourage you to click through to each of our nine watersheds to learn more about water quality scores unique to each. This year, San Diego's coastal watersheds ranged from fair to poor according to our Water Quality Index scoring system.
- Two watersheds scored lower than they did in 2013 (Los Peñasquitos and San Diego—they were good last year)
- One watershed improved its score from 2013, going from Marginal to Fair (Carlsbad)
We're thankful for our 194 volunteers who gave a total of 1,888 hours. And we're encouraged by our 83 newly trained volunteers from 2014.
What watershed do you live on? Find out and click the watersheds below:
Water Quality Index Score: 12, Poor
Let's acknowledge that we only gathered one sample from the Tijuana Watershed in 2014. Thankfully, the Tijuana-based sewage treatment plant handles and purifies 50 million gallons of river water every day, but it can't handle wet weather flows. So, when it rains, the operators divert the river flow without treatment, and that's when we can sample the river. This is also why Imperial Beach beaches are frequently closed during the winter.
Our only sample in 2014 follows a massive rain event in December. That sample showed:
- Bacteria levels were extremely high – even diluting the sample 100 fold, the concentrations were still higher than our test kits can measure
- Ammonia, nitrate, and phosphorus levels were off the charts
- Volunteers had to sludge through very sticky, smelly mud to collect the water samples – thanks!
This watershed presents a lot of cross-border collaboration and love to truly understand and solve the interconnected water quality issues. We're looking for passionate volunteers to get trained in water quality monitoring so they can champion efforts in this challenging watershed. What are you waiting for? Sign up to get trained!
Water Quality Index Score: 53, Marginal
If we're going to call Los Penasquitos the average watershed example of San Diego County, we're going to call Otay Watershed the most consistent watershed in the county. Its consistently high numbers showed:
- Consistently high bacteria levels - Every sample collected exceeded healthy standards for Enterococcus.
- Consistently high Nitrate levels - almost every sample exceeded standards
This also means that this wasteshed runs consistent with our theory that the region's drought has affected water quality in addition to water quantify. At no point in 2014 did the data from Otay Watershed put it into healthy ranges for fecal indicator bacteria or nitrates. But, consistent with all the watershed scores in December, Otay Watershed's scores did worsen after the rain event.
We loved hearing that our volunteers in this watershed also consistently spotted dragonflies, crawfish, and herons while sampling.
Water Quality Index Score: 62, Marginal
Our data in Sweetwater Watershed showed:
Again, another watershed indicative of extremely low water flows creating high nutrient levels and low oxygen levels -- so low that the river is near depleted of oxygen for many of the summer months.
Why should we care? Our volunteers also spot turtles in this watershed, which depend on the river for their livelihood.
Water Quality Index Score: 64, Marginal
A few key takeaways from our Pueblo Watershed data:
- Chollas River sites often had very high phosphorus and ammonia
- 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. This creek is infamous for drying up, also, 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.
We think all signs point toward poorer water quality than shown with the samples that we could collect, and we wonder with more flow would the Water Quality Index Score have returned a Poor rating?
The high phosphorus and ammonia results belong in the nutrient category, which is common in urban areas with regular use of fertilizers and pesticides on outdoor spaces. An extreme example of this sort of pollution occurred in November, when our volunteer team encountered very black water with a foul odor .
That water sample exceeded healthy standards for nitrate, ammonia, phosphorus, and both types of fecal indicator bacteria. It's dissolved oxygen was also extremely low. At first, we thought the black water could have been sewage, but an inspector from the city ensured no sewage lines travel to that location. Turns out, it was just really bad water quality. Our guess? Rotting organic matter or some other industrial waste. As indicated in so many of the other watershed data, the low flows and higher-than-normal water temperatures turned Cholla Creek into the perfect breeding ground for rotting vegetation.
Water Quality Index Score: 62, Marginal
2014 was not a good year for the San Diego River. It dropped two levels on our Water Quality Index score, moving from Good in 2013 to Marginal in 2014, and giving it the dubious honors of being the only watershed to get worse. Key data takeaways include:
- Commonly high levels of phosphorus and ammonia
- Extremely low levels of dissolved oxygen more often than not
- Repeated reports from our volunteers noting excessive amounts of algae and duckweed
This is an excellent example to demonstrate how the region's historic drought conditions impacted water quality in our inland waters last year. I grew up playing in the water at the old mission dam, which has one of our sampling sites nearby, and I can't recall the water levels ever reaching the lows that we saw this year
All three bullet points in the San Diego Watershed data relate to one another and differently demonstrate high amounts of nutrients in the river. To say the least, this river is out of balance.
High nutrient levels, which often start as fertilizers on our lawns and gardens, cause algae and duckweed growth, which ultimately deplete oxygen levels and kill marine life. We think the low water levels contributed to slower flows and warmer waters, creating the perfect breeding ground for explosive algae growth in the San Diego River. And greatly impacting water quality.
Water Quality Index Score: 76, Fair
Well, here it is: the most typical, average watershed in San Diego County in terms of water quality pollution and health. Our data in this watershed did not change dramatically from the year previous, nor did it produce any intriguing results this year.
The end point for this watershed, the Los Penasquitos Lagoon, has an official "pollution diet" in place for sediment, which means it's a known problem here. We continue to monitor this closely.
Water Quality Index Score: 76, Fair
Our data in San Dieguito Watershed show:
- Ammonia, phosphorus, and turbidity measuring at marginal on our Water Quality Index Scores
Ammonia and phosphorus are nutrients. In the farm or garden, people add nutrients to encourage robust and healthy plant growth. In the water, however, nutrients are rarely beneficial. Too many nutrients can cause algae to grow out of control, which will blanket the stream and bank with unsightly algae. These mats of algae ultimately lead to oxygen depletion that kill the aquatic life.
This is a huge concern for this waterway because our volunteers spotted lots of wildlife including birds, fish, turtles, clams, crawfish and insects.
The unhealthy levels of turbidity point to excessive sedimentation in the San Dieguito River. The river empties to the San Dieguito lagoon, which is sensitive to this sort of pollution because the river brings sediment into the east side of the lagoon and the Del Mar Racetrack and associated parking lots impact sediment flows on west side.
Water Quality Index Score: 72, Fair
To no surprise, our 2014 data showed that:
- Nitrate is consistently high in upper Escondido Creek
In fact, four of the five samples with the highest nitrate concentrations collected anywhere in San Diego County this year came from Escondido Creek. Because of this, our volunteers report seeing a lot of algae growth in the water.
We're not surprised because nitrate always measures high in Escondido Creek, but we're interested in learning why this consistently happens. Recently, we inquired with the City of Escondido, and representatives say it comes from groundwater and the legacy pollution from the agriculture industry. Thankfully, our longtime volunteer and new board member, Taya Lazootin, is running a research project examining nitrate in Escondido Creek to figure out what's happening. We're hoping her final report has more insights into this problem.
Water Quality Index Score: 77, Fair
We tracked two parameters of concern in San Luis Rey Watershed:
- Turbidity: Two-thirds of the turbidity samples exceeded healthy standards
- Levels of pH: Over half of the pH samples collected exceeded healthy standards
Spoiler alert: Our volunteers saw the impacts of these poor water quality indicators play out when they reported numerous dead fish along the river's bank in March and April.
When turbidity exceeds standards it means too many sediments are moving through the waters. We especially care about this in the San Luis River because it has a small tidal wetland where the fresh river water meets the coastal salt water. When the river carries unusually high amounts of sediment, it will deposit into the wetland, building it up and changing the habitat in this critical area. We'll lose marine habitat because the ratio of salt and fresh waters will change if the salty tides can't breach the sediment build up. This tidal wetland is an important brackish habitat for species like mullet fish and birds.
We're not sure what's raising the pH, and we'd like to research mines or factories in this watershed to understand how they may affect pH levels. We can tell you that it's unusual for pH to be high, especially in river water. For healthy fresh waters, every river needs a certain window of pH--not too low and not too high. In San Luis Rey, the high levels of pH essentially stress the organisms that live in the river. It can also increase the toxicity of existing pollutants like metals and ammonia.
Unfortunately, our volunteers spotted fish kills in March and April--dead mullet fish that suffered from these exact cycles.
Side story, when we found these fish kills, we worked with the Regional Water Quality Control Board to understand more about what was happening. High nutrient levels in the water right after a rainstorm cause algae growth. During the day, algae pumps out oxygen, and then it reabsorbs it during the night. During our daytime tests, oxygen values were through the roof. When we investigated further, in the middle of the night at 2 a.m., oxygen levels dropped causing oxygen depletion, and dead fish.