I would not have thought it probable that crocs or gators did live in sewers, but I think it has been shown that in some cases they in fact do. Though I doubt they breed successfully. Where they are found it seems they are quickly bumped off.

What allows these animals to make it in this unnatural environment? I would suggest it is because every sewer may be different and here and there are niche environments where they can survive. A description of these would not be found in any text book. In some there could be links with ancient sewers no longer used or natural cave systems. There is almost certainly ground water and flows (in the UK at least) and huge leakages from water supplies.

Isn’t it true that even people manage to live in sewers, rarely I hope!

As far as the sewers go, I’ve done some research and found that there are indeed some places with combined sewers and those municipalities actually “treat” or clean the stormwater just as they do the raw sewage. So in a combined sanitary/storm system the raw sewage would be somewhat diluted, but that would only apply during heavy rain storms. I would venture to guess that the municipalities that would require combined systems are those that typically experience less annual rainfall than others and also have very scarce natural waterways to route the stormwater to. In Florida and in my state (Alabama) for example, most places wouldn’t have combined systems because of the availability of natural waterways (branches, streams, creeks, rivers, ocean) to discharge the water into. But New York, due to the size of the city, would probably benefit more financially from treating the stormwater than to pay for the cost of extra piping to route the water to natural drainage features. So I’m kinda going back on what I said before about the systems not being combined, I have found that there are some places (New York for example) that do actually treat stormwater. But as far as my original position of not really being too convinced personally of the possibility, it still stands because all the other issues I have regarding full flow, gators not being reported to have been washed into the treatment plant or surface through a curb inlet, etc, still apply.

Super-Predators: Humans Force Rapid Evolution of Animals

One point about sewage water quality. In the UK rain water from roofs, yards and I believe roads is normally drained through the foul sewage system and this may considerably improve the quality of the water and purge the system. Does this not happen in the USA? I imagine in Florida for example there would be a lot of water from its high rainfall not all going via the storm drains.

Alligators typically need larger prey at larger sizes, need deep water to roll and do not do well in high bacteria environments without sunlight (or desire to go in the sunlight). These distinctions, plus the fact that alligators don’t belong in NY might be enough to classify such a creature as a cryptid.

I know this stretching a little, but recently an African elephant sub species was found (I think I read about it on Loren’s site?) with only minor evolutionary differences.

This photo looks like a classic sanitary sewer photo. There are a few things I can point out about the photo. First, look up at the very top of the photo where the bricks are bright red, this is the high water line, where sewage flows have gotten somewhat severe, actually very severe, and this would represent “full flow” at its peak. At the moment the photo was taken, the sewer appears to be experiencing normal flow conditions, indicated by the fact that the sewage flow level is contained completely within the invert. The 2 areas on either side of the invert are called “benches” and were constructed so that maintenance crews can get down there, manuever, and do whatever work is needed during low or normal flow conditions. Near the bottom left of the photo, there appears to be an accumulation of grease, which is what usually causes most of the obstruction problems inside the sewers. Most restaurants have grease traps, but the grease from residential kitchens typically drains into the public sanitary sewer system, and it tends to accumulate as shown.

The benches would be an ideal spot for gators to lounge during normal and low flow conditions, but during full flow you can see from the photo how the capacity of the pipeline is challenged and there is nothing to hold on to in order to maintain position and prevent being swept downstream and possibly into the sewage treatment plant.

Just to clarify, I want to make sure you understand where I was coming from on this, when we were talking about the gators “eating” sewage in the sanitary system, I wasn’t trying to imply that the gator would have to resort to eating sewage to survive, but was actually trying to point out the fact that accidental ingestion of raw sewage would be a problem. Any rats down there are likely to be covered in liquid poop to some degree or another for one, so that is one source of accidental ingestion, as well as other ways I can think of like if the gator is swimming in the raw sewage and opens it’s mouth to take a food item then more raw sewage could be accidentally ingested. I don’t want to list all the ways, there are endless possibilities as to how the gator could accidentally ingest raw sewage just going about his normal routine in cesspool conditions. And I don’t know how much of a health concern that would be for a gator, but I would tend to think that could cause major health concerns (disentary for one) as that isn’t really the same as decomposing flesh. I guess it is safe to assume the gator’s ability to ingest decomposing flesh is due to the bacteria within his digestive system? However, decomposing flesh and “highly concentrated disease-ridden fecal matter” are 2 different things. Anyway, that is the point I was trying to make in far less words earlier, sorry if my point wasn’t clear.

As far as heat in the storm sewer - You are right, with the storm sewer being so open, it doesn’t have the same ability to trap heat like the closed system sanitary sewer. Here is a good way to look at that I think: (For the Sanitary Sewer) Imagine it is winter and only 30 deg F outside. You are in your house and the heat is on and you are nice and toasty. (For the Storm Sewer) Imagine the same exact conditions outside, now you go open all the doors and windows and leave them open. You wouldn’t be nice and toasty anymore, huh? And I don’t feel that is an exaggeration either really. Also, while there would be some decomposing matter in the storm sewer that has the potential to produce heat, it is mostly in the form of trash that washes into the inlets from the streets, so you don’t have the same magnitude of heat producing decomp in the storm as you would find in the sanitary. So I absolutely agree, in the winter, the storm sewers would not be conducive to gator survival. And you can also consider some of the extreme situations of NYC storm sewers in winter. Say you have a substantial snowfall and when it begins to melt, the “nearly freezing” water drains into the storm sewers and comes into contact with these cold-blooded reptiles and their food source. I would think the consequences of such a situation have the potential to be fatal. And of course a heavy snowfall, several inches, melting quickly would cause full flow conditions of water that is just a bit over the freezing point.

Back to sanitary - As far as system design, the upper reaches of the system is comprised of small pipelines, but as you get farther downstream the pipe sizes being to get larger in diameter. This is because the flow accumulates and gets larger the farther you go down the system. Consider a few city blocks, starting at a dead end, but getting more and more dense as you go: If the sanitary line begins at the dead end, there may only be one service tap discharging into the end of that small main, but as we go down the street, more and more service taps discharge into the main, so because the flow accumulates, the next few pipeline “main” segments may be larger than what we started with at the beginning of the system. And that process continues, all the way to the treatment plant. So although at that dead end we may have started with only an 8″ main, by the time we reach the treatment plant, we have increased to a 60″ diameter sewer main (or larger). During peak times (when people use large amounts of water), this 60″ diameter main is probably flowing at least half full, if not completely full. This doesn’t just happen once per day, it happens in the morning, in the afternoon, and in the evening. So we’re talking about at least 3 “peak times” per day when the liquid poop, toilet paper, condoms, hemorroid pads, tampons, chunks of grease from restaurants etc. are flowing full. Of course the morning flows (before work, cooking, bathing, etc) and the evening flows (after work, cooking, bathing, etc) are the most substantial flows. So the area immediate to the treatment plant would experience the heaviest flow activity, massive flows of the most horrendous substance you could imagine. Ugh, I think I’m gonna be sick now, lol. But as far as a gator being able to avoid the flows, I’m personally not seeing the possibilities of how this could be accomplished. There aren’t any “gator rest stops” along the liquid poop superhighway

One of the commenters above mentioned something about “sandbanks” in the sewers where gators could chill out. All I can say is that unless you’ve spent substantial amounts of time in sewers and working with them you may not understand that it isn’t really a poop river with “sandbanks”. I didn’t really understand the comment, but as far as sandbanks, I wouldn’t spend too much time entertaining that notion.

And as far as the gators not wondering out into the treatment plant during spring, summer, or fall, or getting washed out by the flow conditions, I honestly can’t see this being avoided long-term. Even in sewers that aren’t cylindrical, the ones that are designed to be more square or rectangular, all the same priciples of full flow still apply. Even with the sewers that are rectangular with an internal trough to channel flow, you can compare those to rivers that don’t stay within their banks, eventually there will be flow conditions that test the integrity of the system and exceed normal capacity and would wash everything into the treatment plant.

So yeah, like I said and like you said, this could very well only be the tip of the iceburg, and it appears highly likely that we could actively debate this with new info and new examples, every day from now until the end of the world in 2012

I’m begining to wonder if we need to start a list with all the pros and cons for each system, so when we reach a consensus on a particular issue we can just move on to the next without backtracking too much, lol.

I think I will spend some time over the weekend trying to come up with possible answers, or lack thereof, for ways that gators could avoid full flow in both sanitary and storm. So far I haven’t been able to think if anything that really convinces me, but it is worth looking into. I just have to spend time running different scenarios through my head and maybe even see if some of the hydrology or pipeline/channel flow software I have could be of some use. In storm, even upper reaches (smaller diameter) pipelines experience heavy flows and high pressure and velocity in extreme precip events, so this is going to require some creative thought in trying to figure out system design parameters that would make this a possibility. But off the top of my head, and using the storm system design parameters that I am accustom to, I have to say that storm systems are designed specifically to drain water completely without retaining any water in the system. And to accomplish that, you want to get the water out of the system and into natural waterways/drainage ways as quickly and efficiently as possible, hence the high velocities. But like I said, there are no “rest stops”, public money is monitored very frugally on infrastructure construction projects, there really isn’t room for redundant sewer lines, each one has a purpose and is sized to handle its expected load. But I will be back here Monday to see what new info is available. Have a good weekend

Storm sewers have a lot of pros to them. For one, a more ready food supply, even if it was only more rats and some domesticated animals like cats. The conditions are also relatively cleaner, although like you said there are chemicals and other things that still make them far from ideal. There seems like there would be more opportunities to get sun, as I’d imagine there are more ways for sunlight to enter the storm sewers. There are also more ways that a gator could be introduced there to begin with. These are all very compelling factors, but the cons are considerable.

The storm sewers are not going to be nearly as warm as the sanitary sewers, if the the information I’ve gotten here is any indication. This is a major drawback for a reptile like this. As you are no doubt aware, these animals need warmth to survive for a great many reasons, including for proper food digestion among others. If you think the odds are low that a breeding population can survive in the sanitary sewers, the chances go down considerably if the animals are living in a cold environment with little to no additional warmth generated by decomposition. Also since there seems to be more access between the storm sewers and the outside, there would be more opportunities for any such warmth that was produced to escape the habitat. From your information, the storm sewers don’t seem like they’d offer any more protection or insulation from the cold than outside in the open. There could be warmer places there, but I’m not seeing how, so this by itself is almost enough to make me think the storm sewers are unlikely for a population of gators.

On top of that, you bring up the very good point that there would be many more opportunities for these storm sewer alligators to be seen. Also, full flow. Your description makes it seem like a formidable challenge, however as Loren said, maybe the gators are escaping it somehow.

Sanitary sewers have a major pro in that they are warm enough to comfortably support an alligator. Also, if the food supply is even adequate at all, it could be enough for an alligator to at least eke by. The gator might lose weight or be less than satisfied, but with its slow metabolism it might get by with what is on offer. I don’t think the gators would necessarily have to resort to eating decomposing waste if they could get enough rats. However, I’m still not quite clear on just how many rats we could expect to find down there so it’s hard to calculate.

Also, the gators would be better hidden from view by people, unless they found their way to treatment plants, but I will soon address this potential problem.

Still, there are some potential cons. One is the lack of sunlight. I still would think this is a challenge for the gators, and am not sure what the processes would be in effect that would allow them to actually grow larger in these conditions, as was stated earlier. I’ll wait for more information before saying too much about the sunlight factor.

Also, you bring up some good points about the sewage treatment plants and the pray that would be more available there, but as I said before, there are a few reasons I can think of that these gators might avoid that. First of all, they wouldn’t want to venture anywhere too cold (although who knows in the summer time). They would be more inclined to just stay in a nice, warm spot. As far as prey goes, if they could get enough rats while the getting is good, they could wait out the periods where the rats are scarce. These alligators do not have to eat nearly as often as warm blooded animals. If they could have even just occasional periods where they could get enough food or a even a small but steady supply, for example as it flows past them on its way to the plants or any rats wandering around, they could probably go without having to track it down at the treatment plants. Like I said, not really “living,” more like “surviving.” But as far as illustrating the actual biological feasibility, I’d say it’s possible.

I agree that we could probably expect to see at least one come out into the treatment plants, but none has, so I’m just speculating and exploring the possibilities for why this might be.

Then we have the sanitary conditions, which admittedly sound very rough. As I said before, I don’t know of any study or hard data on what the effects of an alligator living in raw sewerage, or (hold on while I gag), liquid poop. It’s hard to say with absolute certainty, but in my own opinion alligators can handle some fairly rancid conditions. You can get gators in small, mostly dried up, muddy ponds just absolutely redolent of animal feces from other gators, birds, and the animals that come there to drink. Probably still not as awful as the conditions in a sanitary sewer but still testament to the hardiness of these animals. I wouldn’t go as far as to say that surviving the cesspool conditions is not improbable at all, but in my opinion it’s perhaps possible and something to consider.

Full flow conditions even in the sanitary sewers still sound daunting, but perhaps there are ways that we are not even thinking of that the gators avoid this. Like you said, we are likely only at the tip of the iceberg here. It seems the issue of alligators in sewers is not a simple one to get to the bottom of.

I’m glad to see that perhaps my comments are making you think about the sewers in new ways, as well as the biological possibilities involved here. I know your comments are certainly educational and have taught me a lot about the sewer conditions. Your opinions are most definitely wanted here.

Give me a discount on those consulting services, Ok?