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Saving Laguna Lake 

What will it take to make the lake thrive?

In the early morning, just as the rising sun begins to filter through the grove of towering eucalyptus trees along Madonna Road and the sky changes from a pinkish gray into a deepening blue, Laguna Lake can look amazingly inviting - a shimmering plane of reflective glass broken only by the V of a treading Canadian goose or mallard duck. By afternoon, however, there's no mistaking that the "lake" is little more than a smelly mud hole befouled by agricultural runoff and waterfowl excrement, increasing sedimentation from Prefumo Creek, and chemicals to kill everything from mosquito larvae to algae blooms.

The only lake in the city of San Luis Obispo proper is at risk of disappearing altogether, growing more marsh-like until it turns to meadow. How did the lake fall to such a state, and how does the city plan to save it? The first part of the question is easy to answer, the second much more difficult. What seems certain is this: It will take millions of dollars to "fix" Laguna Lake.


The past

  • Christopher Gardner

#The first historical mention of Laguna Lake came in 1769 in the diary of Spanish Explorer Gaspar de Portola during an expedition to California in 1769 to 1770. He briefly described it as a freshwater lagoon. Since it was September, it must have been a wet year, because what we now call Laguna Lake was most likely a seasonal wetland.

"It was originally, I imagine, just a low spot," said SLO City Engineer Barbara Lynch, who's currently - among many other projects - exploring the alternatives for deepening the lake to recreationally usable depths.

It really became a lake during the construction of Los Osos Valley and Madonna roads, said Dr. Tom Rice, a Cal Poly soil sciences professor: "Laguna Lake was more of wetland, not a lake; but the two dams - at Madonna and Los Osos Valley Road - took what in the past was a historical wetland or seasonal lake and made it a year round lake."

To keep the lake filled with water, Prefumo Creek was diverted to flow into it, explained Mayor Dave Romero, who at that time - about 1959 - was the SLO city engineer and public works director.

"We gave permission to divert Prefumo Creek when developer Ray Skinner did the first Laguna development on south side of Madonna Road. In the old days, the creek angled across the corner of French Road, right about where the Shell Station is on the corner of Madonna and Los Osos Valley. Then it went by the fire station, by [Pacific Beach] continuation school, and into San Luis Creek. When we agreed to it, we were thinking about Laguna Lake as a recreation lake."

The idea was to have Prefumo Creek feed the lake and have the lake overflow go under Madonna Road and into San Luis Creek. Unfortunately, these good intentions led to flooding problems and proved to be the very reason the lake is now filling in with sediment.

click to enlarge DOGS, DUCK, AND ... DANGER!:  Laguna Lakes beauty attracts plenty of people, but pollution makes contact with the water potentially dangerous, and increased sedimentation has made the once popular windsurfing and sailing spot - difficult to navigate. - CHRISTOPHER GARDNER
  • Christopher Gardner
  • DOGS, DUCK, AND ... DANGER!: Laguna Lakes beauty attracts plenty of people, but pollution makes contact with the water potentially dangerous, and increased sedimentation has made the once popular windsurfing and sailing spot difficult to navigate.

#"It was anticipated that some sediment would flow into the lake," said Romero, "and we put some check damns in Prefumo Creek right by our little golf course to slow down the water flow. It worked marginally, kind of did the job, but not completely. And we didn't anticipate the storms.

"We had huge storms in 1969," continued Romero, "which destabilized the watershed. Roads and creeks washed out and huge amounts of silt and debris washed down into the Lake. The whole arm of Prefumo Creek silted in. Then we had big storms in '73 and again in '82. It never did stabilize completely."

The storms were so strong that Romero was actually considering destroying Madonna Road at the south end of the lake to allow more water to flow out and into the creek.

"The three major storms that hit in '69 were bad, but the flooding in '73 was the most intense since I've been with the city," said Romero. "I was considering doing it - destroying Madonna Road. It would have caused terrible problems, because when you do that you isolate a lot of people and there's a huge cost to bring it back because we would have had to cut through sewer, water, and gas lines. But all of Oceanaire was covered in water and it was up to many of the houses. It would have been a really tough, nasty decision."

Eventually the culvert under Madonna Road was enlarged, and with annual creek clearing activities, chances of flooding around Laguna Lake have been minimized. On the other side of the coin, droughts have also taken their toll on the lake. In 1977, for instance, the lake all but dried up. The only water left was at the south end, as Dr. Tom Rice recalls: "I walked on it at that time; it was amazing, the clay deposit with two- to three-inch-wide cracks that went three feet deep."

While the drought of '77 may have seemed like a good time to get earth-moving equipment into the lake and dig it out, it wasn't that simple.

"It looked like the lake was dry," said Romero," "but underneath it was still a mucky mess. We had a couple cars out there, and they got stuck and had to be towed off. It doesn't lend itself to earth moving because it doesn't dry out underneath."

In fact, it wasn't until the drought of '77 that the city realized how bad the sedimentation problem had become. "This focused public attention on the lake and the fact that it had been slowly filling with sediment," reads a document prepared by city staff. It also led to the "Laguna Lake Management Program," adopted in 1982, which began a program of mechanical weed harvesting, sediment removal from the Prefumo Arm, and installation of a log barrier at Madonna Road to adjust the lake level.

The City Council revisited the sediment problem in 1991 and directed staff to "pursue removal of the delta at the mouth of Prefumo Arm and begin an Environmental Impact Report (EIR) for dredging five feet of material from the entire water area of the lake."

Fourteen years later, the only efforts to fix the lake have been occasional removal of silt where Prefumo Creek enters the lake, once in 1995 and again 2002. Meanwhile, the lake has become more and more shallow, which has led to a host of problems.


The present

  • Christopher Gardner
  • DUCKS:

#Shallow water is easily warmed by the sun, leading to increased weed growth, more algae blooms, more mosquitoes. Warm water also doesn't retain oxygen as well as cooler and deeper water; a situation that leads to fish kills, more algae, stagnancy, and mosquitoes. In an effort to control these problems, the city has implemented a variety of programs.

Mosquito abatement comes from treating the water with Bacillus thuringiensis israeliensis (BTI), a biological larvicide that kills larvae. But at the north end of the lake where weeds and reeds are thick, it's difficult to treat the water. BTI isn't a chemical poison, hence it isn't necessarily destructive to the environment, but if the water was deeper it probably wouldn't be needed as frequently.

Occurrences of blue-green algae blooms have increased and become worse in recent years as the lake has grown more shallow.

"I've been faced with in maintaining the lake, trying to control the periodic natural algae bloom that occurs in ponds and waterways under all sorts of different environments," said SLO Parks and Urban Forest Supervisor Todd Beights. "It's a cyclical thing. We sometimes go a few years without having a real problematic algae bloom, but when we do we treat it with copper sulfate and citric acid. We only use it to control the bloom in certain areas of the lake."

When the blooms occur, the biggest mess usually ends up near Madonna Road since the prevailing winds push everything - algae, flotsam and jetsam, trash - in that direction. It's a sad sight when that end of the lake is an opaque, nearly fluorescent green and the shore is littered with trash. It also stinks.

"That's the bloom after it blooms and dies," said Beights. "It creates a musty odor."

When the lake is at its worst, it couldn't be less inviting. It looks downright polluted.

"We take samples three times a year to test for things relative to what we're putting in - heavy metals and copper - but the tests have never shown a detectable level," said Beights.

So the lake is supposedly safe, yet "No Swimming" signs are clearly posted along its shore. Why? Is it because of chemicals?

"No," said Parks and Recreation Department Director Paul LeSage. "The swimming is the matter of safety. There are parts of the lake where dramatic drop-offs occur. If someone was a non-swimmer, they might walk out into the lake and drop into water over their head. That happened in another community. And lake resources seem to attract people who can't swim."

Of course there's no way to know for sure if the water is safe for swimming or not. The city doesn't conduct testing to determine water contact recreation safety.

The last time the water was officially tested was in 2001, when the Regional Water Quality Control Board did a study. They found that fecal coliform levels were above safe contact levels.

According to Regional Water Quality Control Board Environmental Scientist Christopher Rose, "From the 2001 data, although it was a limited data set, we found the fecal coliform in Laguna Lake exceed both county and state standards for water contact recreation."

In short, there were unsafe standards of fecal matter in the water in 2001 and no one's checked to see if it's gotten better or worse since then.

"Our job is to present data, and it's up to the county or city to do posting," said Rose. "What they put up is along with their guidelines. That said, although the data shows that it exceeds state standards, the fecal coliform concentration just barely got over the limit. In fact, it wasn't over all the time, only some of the time. The way fecal coliform is, you can go out to the lake one day and be far lower and then go out the next day and exceed the threshold, so it's a very fluctuating parameter or pollutant. Although it exceed standards, there's nothing from our agency that says it's unlawful to have contract with the water, it just exceeds water contact recreation standards."

"Would you swim in it?" asked New Times.

"Hmm. No," said Rose.

"Would you drink it?"

"No! Certainly the fecal coliform levels far exceed state standards for drinking water."

"Would you let your dog swim in it?"

"Hmm. I think that dogs drink out of puddles and many other sources, so sure, I would let my dog drink out of it."

"Do you have a dog?"


Since no current data of the fecal coliform level in the lake was available from any government agency, New Times decided to sample the water. We took three samples from three different spots in the lake and delivered them to Creek Environmental Laboratories, Inc. in San Luis Obispo. While certainly not scientifically exhaustive, our simple one-day sampling showed the water exceeded water contact safety standards.

According to the lab's president, Orval Osborne, standards say 1,000 coliform and 200 fecal is acceptable for water contact recreation. Near the boat dock, our numbers were 130/80 - within acceptable levels. Where most of the waterfowl gather, our numbers were 5,000/5,000 - way over safe levels. At the south end of the lake, we found 3,000/3,000. Currently city signage says, "Limited water contact, as part of sailing or paddling activities, is permitted."

The more limited the better.

It wasn't too long ago that Laguna Lake was a popular windsurfing spot, but these days the water is too shallow for the centerboards to keep from hitting the bottom. You still occasionally see boaters out there, but not often. People do fish in the lake, and according to Fish and Game, they are edible, despite the pollution. Sadly, Laguna Lake's recreational value is almost nil, but it's still pretty to look at ... for now. If the lake isn't deepened, it's not going to be a lake anymore, and mosquito, sedimentation, weed, and pollution problems are going to get worse, leading to a smelly, mucky mess.


The future

"We've got consultants working on environmental studies, looking into options for dredging," said City Engineer Barbara Lynch. "We brought to the Council options for dredging, costs for the various options. It's all very expensive, and for a city our size, we don't have $10 million just lying around to spend on something like this. Naturally there's some consternation."

Not only is dredging the lake going to be expensive, it's going to create something of a mess. All the dredged material has to go somewhere.

"Dumping a huge quantity of this slop didn't have a lot of curb appeal," said Lynch. "We also looked into a smaller annual dredging project, but I'm not sure the neighbors find that proposal too appealing. It's one thing to deal with a two-year project and then have it done with, it's another to have an ongoing project that happens year after year."

Mayor Dave Romero favors the smaller annual dredging project for economic reasons.

"There are floating suction dredges," said Romero, "and we looked into that in the '80s. The slurry could be pumped to the back acreage of Laguna Lake, allowed to dry, then mixed into the earth as soil amendment."

Cal Poly's soil science professor Dr. Tom Rice isn't sure the sludge would help the soil: "It's loaded with clay and undesirable physical properties. It's fine for lining a pond, but it has no agricultural purposes."

Still, Mayor Romero, nothing if not a realist, knows that hauling the material away simply isn't practical: "In my view, the easy answer is reactivate this dredging plan. Some people think we should not disturb the open space back there, but to me, we'll save millions. The most economical thing is to dispose on site and amend the soil.

"You know, most of those houses along Oceanaire are built on fill from Laguna Lake," said Romero. "Raised land was created along the shore. In the late '60s we did work on the park side, took out a small island, raised some of the park that was filled with that material.

"The ongoing program is the one I pushed and argued for because the city simply doesn't have the money," continued Romero. "We're talking about millions of dollars, and we're talking about hauling semi-wet loads of material out of there, which will damage our streets. The Council wants to preserve that as a lake, we don't want it to become a marsh, so at some time the Council will have to make a decision. I can't see in the foreseeable future that we'll have money to do major dredging operation. People want to spend money on better streets, faster paramedic response."

Even the annual program will cost a bundle.

"We're looking for grant opportunities, but those kinds of funds are usually reserved for habitat protection, and this project is more to increase recreational opportunities," said Lynch. "The goal is to finish the environmental document, which will give us a better view of what needs to be done, show us if mitigation will be required, and it could give us a leg up in grant opportunities.

"In the recent survey about raising the sales tax, we asked whether citizens favored fixing the lake, and there's not huge support for it," said Lynch. "The numbers look pretty good until you start comparing them with other priorities. If the city were to get that sales-tax money, they'd go down the list of things that need doing, and dredging the lake is not high on the list.

"I think at some point we'll dredge the lake, but it may not be tomorrow," continued Lynch. "A lot depends on what happens to the city. If you have a bridge failure like we had at Foothill and you have a lake that needs dredging, where are you going to spend that money? We're dealing with covering the bare necessities, and we're not even doing that now.

"I get to look at the bottom of bridges and videos of storm drains, and so I have a different perception of the state of our infrastructure compared to the average citizen. When you poll people about where they think the money needs to go, paving always seems to come out on top, but that's because that's all people see. I could spends millions and millions trying to get everything updated, but we're in a situation where we can only fix what's immediately failing."



Laguna Lake Park is a gem, 375 acres that feature three small picnic areas, a large group barbecue area near the children's playground, a group barbecue area at the Pavilion, restrooms, a sand volleyball court, par course fitness trail, the city's commemorative grove of trees, and one of the city's few dog parks. The lake is a migratory stop and home to a variety of waterfowl.

"It's a phenomenal resource, a haven that allows your mind to calm down and relax," said Parks and Urban Forest Supervisor Todd Beights. "There's nothing else like it in the city. My gripe is I'm in charge of taking care of the urban forest, and I've had the same budget and staffing levels since 1978. If the public loves trees and loves parks and we continue to build them but don't attach maintenance funding that keep them in good shape, we'll have a bunch of parks that are less than inviting."


Glen Starkey walks his dog at Laguna Lake every morning. Complain about the pile of dog poo at


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