Lake Event Documentation

For many years when Bob Bourke lived on the Lake, the community relied on him to document events that impact our Lake. Since moving to the Mainland, Bob has continued to advise ELRA on environmental issues. Bob is a trained environmental scientist with over four decades of experience in water ecosystem management. When he lived here, Bob took primary responsibility for responding to, documenting, and reporting on runoff, flooding, and ecological events impacting the Lake.

But now that Bob is no longer physically present it’s up to us as a community to document these events in a manner that allows for them to be quantified. Bob has provided ELRA with guidelines for documenting the “when”, “where”, “who”, and “how much” for each event. The topics below provide guidance on how to respond when events occur.

Contact Lake Security 858-247-7738, Submit the event information as completely as possible, and how best to contact you, to

Take photos. Include a picture of a watch or front page of a newspaper in the photo to document the day and time.

When did the event start? How long did it occur? When did it stop?

Did the event happen at a continuous level or did its intensity peak and then taper off over time? Over what period of time? Days? Hours? Minutes?

Where the pollution is coming into the Lake is important, but it’s more important to follow the flow of the pollutant back up-stream to its source. Sometimes this may be difficult to do because the flow is buried in the storm drains. You can find a map of the storm drains on the ELRA website. When in doubt, just walk upslope until you find the source. When the source is found, take photographs from multiple angles being sure to get both close-ups and distance shots to better define the area and source of pollutant load. Often you will find a construction site is the source of the pollution or muddy runoff. Detail a street number or describe the area in your report so that someone not familiar with our area can locate it.

Who is present at the source of the contamination? Does it come from a private residence? Are there trucks with logos on their doors? Take photos of trucks, houses, and people.

Ask questions to find out what happened, when it happened, and when it’s going to stop.

How much is always the trickiest question, but there are a few simple tricks to help quantify the answer.

Take Water Samples.
Buy a bottle of water, empty it, and then fill it up with water coming from the pollutant flow. When you fill up the bottle, take a photo and, if possible, a video of the water from which you are taking the sample. The photo/video will document the quantity of water flowing, and the sample will document the amount of pollutant in the flow.

Put a label indicating where and when it was taken and put it in your refrigerator. It’s quite acceptable to take multiple samples (and photos) over time if the pollutant event goes on for a while.

Bob Bourke (808-256-2057) can tell you where to take the sample and what to have it analyzed for.

Estimate the Quantity of Sediment.
The other way to estimate the quantity of sediment eroded into the Lake is to measure the amount of erosion at the source site. Photos of the hole created (once the water has been drained), or documentation of how much material (# trucks, # cubic yards) required to fill the hole after the repair was made, would provide an excellent estimate of the quantity of material that flowed into the Lake.

Collecting and reporting the above information will help the ELRA document negative environmental events and, hopefully, establish responsibility for pollutant loads with appropriate compensation to help with clean up.

Fortunately, we now have an excellent benchmark to value the cost of removing sediment from the lake. The recent dredging cost, including permit costs, is about $1.25M for the removal of 4,800 cubic yards of sediment – or roughly $260 per cubic yard.