Diving after it rains

[RonFrank]

This is location specific, and depends also on if there is just some rain, or a significant storm.

In Coz, it rained several days while we where there. The only impact to diving was the loss of sunlight when the sky was overcast. It also made for colder surface conditions especially on a six pack.

In the Keys, one is diving 5 miles out, but the dives can be shallower, and storms can definitely stir things up. An afternoon rain does little unless it is accompanied by big surf.

Runoff impacts diving off the FL mainland, no doubt.

In lakes around CO, if the shore is rocky runoff is less an issue, but many are not, and a good rain can turn bad vis to almost zero vis.

You will need to discover/learn how rain impacts the area you choose to dive. Locals are a great resource in this regard.

 

[SkipperJohn]

near to shore the dangers are directly related to how many pets there are in the area and how many well groomed lawns. Rain begets bacteria either from fertilizers or form unscooped poop (even after it's picked up some remains and no one seems to be picking up the #1).

 

[Coldwater_Canuck]

near to shore the dangers are directly related to how many pets there are in the area and how many well groomed lawns. Rain begets bacteria either from fertilizers or form unscooped poop (even after it's picked up some remains and no one seems to be picking up the #1).

The soil will absorb most of the bacteria in these cases. I really can't see how there would be much difference due to rain in diving. Sewage is emptied whether there is rain or not. The storm sewers will start flowing, but the water in these is relatively clean.

 

[seaducer]

Just a thought, but where do you think that pollution goes that you wait a few days for? Does the dump that Uncle Harry took that got washed out to sea just go away? You may think so but I wouldn't bet on it.

Again, that will depend on where you are geographically. My local area for example, the bays will catch a lot of runoff from the roads and sewers, and in this more or less lake like situation the levels will be thrown off. During tide swings the inlets will be pulling all that poluted water out through them where it disperses with the ocean currents. A week or so after a rain the levels that rose with the storms are back to normal.

Here it really only effects things if we have had a particularly long dry spell followed by heavy soaking rains. This allows alot of oils to accumulate and also a lot of trash to fall into the sewer traps, only to be suddenly brought out to the bay. Otherwise the levels are safe and fairl constant. I have never heard of beaches being closed but do know of people who develop ear infections if they swim in the bays right after a rain. Really the best way to tell is to watch the shell fishery alerts and if the clam beds are closed and you are a worry wart, stay outta the water.

Now, that is where I live. I would put alot of stock in what you say about your local conditions considering what you do.
It certainly pays to learn your local conditions and know what to expect.

 

[diverrex]

The soil will absorb most of the bacteria in these cases. I really can't see how there would be much difference due to rain in diving. Sewage is emptied whether there is rain or not. The storm sewers will start flowing, but the water in these is relatively clean.

Not in So Cal. Many here wait 2 -3 days after a heavy rain. Of course heavy rain only happens a couple times a year and generally only Dec - Mar so it doesn't disrupt many diving days. And that's just shore divng, boat diving out in the islands is substantially less impacted.

 

[captndale]

I usually wait until the lightneing stops.

 

[scjoe]

The wait in So Cal is based on advisories issued by the agencies that monitor local water quality. They report high bacteria counts following heavy rains that take up to 3 days to get back to normal. The measurements are taken in the surf zone, so some divers treat the advisories as being more applicable to swimmers and surf, especially if the surf is small. Of course, if the surf is up, then it is the surfers that tend to ignore the advisories and more divers follow them.

 

[Coldwater_Canuck]

Not in So Cal. Many here wait 2 -3 days after a heavy rain. Of course heavy rain only happens a couple times a year and generally only Dec - Mar so it doesn't disrupt many diving days. And that's just shore divng, boat diving out in the islands is substantially less impacted.

Really? What's in those storm sewers? I know they normally pick up some oil and random crap from the streets, and some manure and such from lawns. But unless you are diving right beside the exit point, I figured it would be diluted enough.

 

[diverrex]

Really? What's in those storm sewers? I know they normally pick up some oil and random crap from the streets, and some manure and such from lawns. But unless you are diving right beside the exit point, I figured it would be diluted enough.

Just what you say, oil, crap (literally). With 5% of the US population living within 2 hours of LA beachs it all adds up. It might not be so bad if it rained regularly but since we only average 15 inches a year that may be on 5-10 big rains a year. All that stuff accumulates for a long time and at all once when the rains comes it get's flushed into the ocean. You don't hear of anyone dying from it, but anecdotal reports are that people get rashes, red eyes, etc. Besides it just not fun seeing stuff floating on the water you are diving in.

 

[Annemf]

near to shore the dangers are directly related to how many pets there are in the area and how many well groomed lawns. Rain begets bacteria either from fertilizers or form unscooped poop (even after it's picked up some remains and no one seems to be picking up the #1).

The #1 is Sterile - i.e. no bacteria. #1 is mostly nitrogen [urea], same as fertilizer. Fertilizer does not normally contain any bacteria, either. The pollution problem from nitrogen is the excess "fertilizer" causes excess plant / algae growth. You get a thick green soup that then dies as it chokes off its own oxygen supply. The nitrogen is not a health concern for people, although it does tend to kill off a lot of aquatic life [by depleting oxygen]. This is called eutrophication and it is more of an issue with closed bodies of water, not open ocean. Occasionally the extra fertilizer does support types of algae that produce toxins that are dangerous to humans. An example would be one of the several kinds of Red Tide. This would be close to shore and a heavy rain would help the problem.

Uncle Harry's #2 does contain bacteria, but that is mostly the bacteria that breaks down the waste. There may be other, more dangerous bacteria or viruses but again they would have to be very concentrated as in a river or lake where raw [fresh & untreated] sewage is introduced. This happens, but not in the U.S. Uncle Harry's contribution is well on its way to being broken down as are animal wastes that are not deposited close to the water. Nobody picks up after bears, squirrels, etc. and there's no problem because theres no big pile of fresh ###. A small pond surrounded by homes with malfuntioning septic systems is a concern.

Another point is that "salty" ocean water will kill fresh water or fresh soil bacteria.

Maybe there is a lot of ### in Cali storm drains, but I doubt that's even the issue.
The problem is toxins - all the oils and stuff on the roads, pesticides, heavy metal waste from manufacturing, etc. This is waste produced by people, too, but bodily waste is only a problem when there is lots of it, its fresh, and the people producing it are sick. You have dysentary, etc. where you do not have plumbing and sewage treatment [and everybody uses the river out back as a toilet and garbage disposal] but still not so much in the ocean.

Sometimes heavy rains will cause an overflow situation where untreated sewage [from a malfuntioning plant] is introduced into the water but again, not so much. If I were you folks, I'd worry a lot more about poisons and relax about bacteria that are just doing their job to get rid of waste. We need those bacteria!

By the way, why pick on Uncle Harry, what about you???