Do drains hold water and release it after some time?

tulsi · 22 May 2021, 3:53 pm

I was in a drain that I think is called hawkers folly with two other mates. We were about to explore the last bit of the drain when we suddenly started to hear the distant roar of water. We were confused at first because it was a sunny day with no forecasted rain in the area, but then it got louder. At that point we sprinted past some now agitated bats to the exit. We sat in front of the exit for 10 minutes and noticed that a bit more water was coming out of the culvert then normal. One of my mates mentioned before that some drains hold water for a bit then release it all at once, but I was unsure as it didn't seem very practical. But now I think otherwise.

Does anyone know about sydney water using this method?

Cheers

overexposed photo of the entrance/exit of the drain

ironfistdoug · 22 May 2021, 4:04 pm

The most common thing is when it's sunny where you go in but raining at the upper reaches

tulsi · 22 May 2021, 4:06 pm

we checked the weather radar after and closest rain was in paramatta which we were well away from.

ironfistdoug · 22 May 2021, 8:26 pm

It always sounds worse in the drain. We've thought a tidal wave was approaching and then a shin deep wave would come out.
I've only ever heard rumours of flood gates but they could be possible in some form. There are stormwater harvesting tanks that hold water usually for watering local parks and the like and there are retarding basins to take pressure off the drains further down stream by creating a bottle neck and holding the water in the basin, but both of those would only be releasing excess water during rain. There are also emergency sewer overflows and these can release sewage into stormwater drains at anytime when a sewer gets blocked or collapses. This is obvious because the water is grey, steamy and stinks like shitte

I was up a drain and a bit of water poured in from a nearby hospital. It was hot water and was overpowering us but we managed to get out a manhole.
Another time the water went up a few inches and it stank of chlorine so it was probably someone emptying their pool. Another time I was looking out a gutter box trying to see where we were & I got hit in the face with warm soapy water

Maybe it was just the fire brigade testing their hoses?

dodger · 22 May 2021, 9:59 pm

It sounds more like someone dumping water in a drain.

Detention basins store water when raining and gradually releases it but that doesn't quite sound like the situation you've described.

tulsi · 23 May 2021, 6:08 am

ironfistdoug wrote: It always sounds worse in the drain. We've thought a tidal wave was approaching and then a shin deep wave would come out.
I've only ever heard rumours of flood gates but they could be possible in some form. There are stormwater harvesting tanks that hold water usually for watering local parks and the like and there are retarding basins to take pressure off the drains further down stream by creating a bottle neck and holding the water in the basin, but both of those would only be releasing excess water during rain. There are also emergency sewer overflows and these can release sewage into stormwater drains at anytime when a sewer gets blocked or collapses. This is obvious because the water is grey, steamy and stinks like shitte

I was up a drain and a bit of water poured in from a nearby hospital. It was hot water and was overpowering us but we managed to get out a manhole.
Another time the water went up a few inches and it stank of chlorine so it was probably someone emptying their pool. Another time I was looking out a gutter box trying to see where we were & I got hit in the face with warm soapy water

Maybe it was just the fire brigade testing their hoses?

Just to confirm that there was more water we looked through one of the grates that led into it and we saw more flowing water at about shin level. So it was most likely someone dumping water.

Cool stories as well

tulsi · 23 May 2021, 6:17 am

dodger wrote: It sounds more like someone dumping water in a drain.

Detention basins store water when raining and gradually releases it but that doesn't quite sound like the situation you've described.

Yeah likely was some kind of dumping.

After we went to a grate that was above a room that a rcp led to. It was a dead end because there was a wall with a culvert above that we couldn't get to. The water that was going off of the fall had random bursts of more water. Next to this grate was some small sydney water pumping engine but I think that was related to a close by metal cover that I could hear rushing water going by in.

Thanks for the answers

tulsi · 23 May 2021, 6:18 am

also is this drain called hawkers folly?

yukichaa · 23 May 2021, 11:50 am

Yeah that’s hawkers folly!
Have you tried visiting the nearby Abyss?.. it’s quite a chore to enter from what ive heard

tulsi · 23 May 2021, 1:33 pm

yukichaa wrote: ↑
23 May 2021, 11:50 am
Yeah that’s hawkers folly!
Have you tried visiting the nearby Abyss?.. it’s quite a chore to enter from what ive heard

Ah cool, thanks.

I've had a look at abyss and we were planning on doing it that day but two people couldn't make it so we just did hawkers.