Groundhog Day Floods

[Bill]

The rains still falling and looks set to continue for the next day or so but already the sandbags are out and roads in Longford are closed off yet again due to flooding. I don’t think we can blame global warming for this as it’s been happening like this since I was a kid sixty odd years ago.

The way I see it is that when Sanky brook runs high, there’s just not enough difference in the levels between the brook and the streets for water to drain off quickly enough. There was talk about pumping stations to improve this and I thought this had been done but if it has, then clearly, it’s not working. If pumping were used to move excess water from Longford to Sankey brook, then surely that would simply create problems elsewhere and a better solution might be to lower the level of the brook itself by the creation of upstream overflow pools. These pools could then be drained off when the risk of flooding has passed.

 

Bill 😊

[Davy51]

Perhaps it didn't help when the canal was filled in long ago.

[Observer II]

If you look at old maps of the Mersey Valley and elsewhere, you'll discover huge areas of flood plain which allowed excess rain to be slowed and stored, limiting water course levels.   Since we built housing and hard surfaced these areas of the flood plain,  the run off was increased and river banks overflowed causing flooding.  So basically a consequence of "improved" infrastructure and increased residential build.   If there has been an increase in rainfall due to climate change,  this would seem to call for adaptations in our building practises, such as building at high elevations or altering buildings to abandon their ground floors and provide living space on upper floors only.  On a positive note, with all this water flowing, you'd think it would be possible to tap into all this energy and also increase our storage capacity and distribution capability.    

[Confused52]

28 minutes ago, Davy51 said:

Perhaps it didn't help when the canal was filled in long ago.

In part you are correct. When they filled it in the rainfall levels had been at a low and many of the flooding probabilities in the North West were calculated on an incorrectly low level of rainfall. 

Since the water levels are high at Higham Avenue and Causey Bridges but just close to overtopping at Liverpool Road with a River level which is not high it is clear that there is insufficient capacity in the Sankey. The work at the pumping station near Hawleys Lane is utterly irrelevant when the river level is too high the take the discharge from Densham Avenue.

[Bill]

Looking at the live weather map, there’s an awful amount of rain still to come so I reckon it’s going to get quite bad in a lot of other areas in the next 24 hrs. I don’t think we can change what’s already been done Obs but we could as I think you’ve said before and create overflow lakes that can take up excess water. But for something like this to be any use, the water would have to be released in order for it to work the next time. So no power generated but a lot probably used to pump the lakes out.

 

Bill 😊

[Confused52]

1 hour ago, Bill said:

The rains still falling and looks set to continue for the next day or so but already the sandbags are out and roads in Longford are closed off yet again due to flooding. I don’t think we can blame global warming for this as it’s been happening like this since I was a kid sixty odd years ago.

The way I see it is that when Sanky brook runs high, there’s just not enough difference in the levels between the brook and the streets for water to drain off quickly enough. There was talk about pumping stations to improve this and I thought this had been done but if it has, then clearly, it’s not working. If pumping were used to move excess water from Longford to Sankey brook, then surely that would simply create problems elsewhere and a better solution might be to lower the level of the brook itself by the creation of upstream overflow pools. These pools could then be drained off when the risk of flooding has passed.

 

Bill 😊

Spot on Bill. As I said to Davy the problem appears to be a miscalculation at the Department of the environment when they were planning the New Town and the flood defences around Sankey Valley Park. They don't want to do it but they will have to dredge in the short term. The old path is not available and would in any case probably make the Densham Avenue and Orford Park problems even worse.

[Bill]

But Sankey brook runs into the Mersey Con where it’s tidal so normal dredging wouldn’t work. I know we’ve had this dredging debate before but the way I see it is flood limitation needs to work around the clock and not just at low tide otherwise there’s no point.

 

Bill 😊

[Confused52]

22 minutes ago, Bill said:

But Sankey brook runs into the Mersey Con where it’s tidal so normal dredging wouldn’t work. I know we’ve had this dredging debate before but the way I see it is flood limitation needs to work around the clock and not just at low tide otherwise there’s no point.

 

Bill 😊

Looking at the levels Bill the constraint is not the Mersey but the flow from Causey Bridges to Liverpool Rd.

As of now:

 

Causey Bridge 2.97m

Higham Ave 3.97m

Liverpool Road 4.54m

Mersey at Fiddlers Ferry 3.52 m and the highest it has been today was 4.13m at 0445.

That suggests that the flow rate isn't being managed optimally.

The problem isn't the tide at the moment.

 

Look at the data yourself  River level information for Sankey Brook at Liverpool Road - GOV.UK (flood-warning-information.service.gov.uk)

 

 

[Bill]

Yes, I understand that but what I’m saying is that flood protection measures have to cope with the tides and although I don’t know the Sankey brook situation I know that Spittal Brook at Woolston which is well above the level at Sankey is affected quite badly at high tides.

I’ve just been chatting to my walking friend and he says that a lot of Sankey brook is overgrown with vegetation and he believes that that isn’t helping in that particular area.

Looking at the data, it appears we are already well above the highest ever recorded level.

Sorry the underline wasn't intentional and it won't let me remove it some some reason.

 

Bill 😊

[Confused52]

22 minutes ago, Bill said:

Yes, I understand that but what I’m saying is that flood protection measures have to cope with the tides and although I don’t know the Sankey brook situation I know that Spittal Brook at Woolston which is well above the level at Sankey is affected quite badly at high tides.

I’ve just been chatting to my walking friend and he says that a lot of Sankey brook is overgrown with vegetation and he believes that that isn’t helping in that particular area.

Looking at the data, it appears we are already well above the highest ever recorded level.

Sorry the underline wasn't intentional and it won't let me remove it some some reason.

 

Bill 😊

I am sure your walking friend is correct. Take another look at Liverpool Road, A miracle has occurred, I wonder what could have happened there!!!

 

[Bill]

Yes I saw that and immediately started work on my ark 😊 I’ve just had to nip into the office to check our leaky roof bucket wasn’t overflowing. Spital brook runs alongside and it was running very fast, but I’ve seen it at least a metre higher at one time. I’ll bet the sluice gates at Latchford lock are working overtime at the moment. Here’s a video that I accidentally made down there after a bit of rain.

https://www.youtube.com/watch?v=2y8-hcw7cJk

 

Bill 😊

[Bill]

[asperity]

Apparently the Mersey in Didsbury is at its highest ever level and residents are being evacuated.

[Bill]

I’ve just checked the tide tables and the peak that broke the record (and possibly the sensor) on the Sanky Brook data corresponded to high tide time and similar blips in the level occur at approximately the same time each day. We seem to be in luck at the moment though because the tides are at a minimum.

Thank God for our big storm drain in the ship canal otherwise we'd be in a right mess.

 

Bill 😊

[asperity]

Some houses on Liverpool Road Great Sankey/Sankey Bridges flooded apparently. Andy Carter in attendance with his mop.

[Davy51]

And now it's snowing.

 

[Bill]

That was the sort of snow I like Davy , big thick flakes that give us a nice winter scene but then it’s all disappeared overnight.

I see the Sankey Brook river gauge maxed out last night after passing the previous record high and is now well and truly stuck. https://flood-warning-information.service.gov.uk/station/5085

The gauge would be reporting an average reading over a short period of time but the sensor would have been bobbing up and down with the waves and kept sticking. Looking at the short periods where it did seem to be working it shows that the record was broken but we’ll never know just how high it got.

OMG Check out the drone videos on the news page showing flooding in the Longford and Bewsey areas.

 

Bill 😊

[Evil Sid]

not been flooded out but then again if my house gets to the point of flooding the i will be looking for some guy called Noah.

On a slightly water related theme though. i got woken by Mrs Sid this morning complaining that the light was leaking.( i was hoping to have a lie in for once).

being half asleep i assumed she meant the sink or something. dutifully i got up and went down to find that the light in the hallway between the kitchen and the bathroom was indeed leaking.....😵

On the positive side the bulb was still working despite being half full of water.... got the roofing guy coming later to see why there is water at that point. good job the roof has a guarantee but still got me puzzled as to where the water is coming from.....🤔

[Bill]

I’ve been racking my brains yesterday to try to find a solution to this flooding problem that seems to have gone on forever. We all complain about building on floodplains, but we need housing and infrastructure where we live and being a low-lying town with multiple water courses, we don’t have much choice.

The ship canal has saved our bacon a million times over so why can’t we use the same proven principle to take excess flows from our smaller water courses These wouldn’t be canals but might take the form of several small but quite deep lakes that would be environmentally friendly and if done correctly a valued community asset. It’d be like having an upstream man-made floodplain and by having several small ones, they could be simply be expanded as needs arise.

 

Bill 😊

[Latchford Locks]

53 minutes ago, Bill said:

I’ve been racking my brains yesterday to try to find a solution to this flooding problem that seems to have gone on forever. We all complain about building on floodplains, but we need housing and infrastructure where we live and being a low-lying town with multiple water courses, we don’t have much choice.

The ship canal has saved our bacon a million times over so why can’t we use the same proven principle to take excess flows from our smaller water courses These wouldn’t be canals but might take the form of several small but quite deep lakes that would be environmentally friendly and if done correctly a valued community asset. It’d be like having an upstream man-made floodplain and by having several small ones, they could be simply be expanded as needs arise.

 

Bill 😊

So simple and seemingly effective idea.

Why can't our so called experts who make decisions think so logically.

[Observer II]

On 1/20/2021 at 2:35 PM, Observer II said:

If you look at old maps of the Mersey Valley and elsewhere, you'll discover huge areas of flood plain which allowed excess rain to be slowed and stored, limiting water course levels.   Since we built housing and hard surfaced these areas of the flood plain,  the run off was increased and river banks overflowed causing flooding.  So basically a consequence of "improved" infrastructure and increased residential build.   If there has been an increase in rainfall due to climate change,  this would seem to call for adaptations in our building practises, such as building at high elevations or altering buildings to abandon their ground floors and provide living space on upper floors only.  On a positive note, with all this water flowing, you'd think it would be possible to tap into all this energy and also increase our storage capacity and distribution capability.    

 

[asperity]

Now that Biden has signed the USA up to the Paris Climate Accord again climate change has been fixed and we won't have to worry about the weather again. Amirite? 🌦️🌈🌂

[Bill]

Well digging a few big holes isn’t exactly rocket science and apparently it’s not that expensive either but this extremely simple approach is unlikely to be adopted because the authorities will just make a meal of it as they always do. Here’s how one councillor replied when I asked how he’d go about it.

 I’d spend some money first on 

1. Evaluating the scale of the problem

2. Identifying the causations of the flooding

3. Look at the future climate indicators to see the likelihood and frequency of recurrence

4. Draw up an immediate contingency plan of action to protect what people have now

5. Put in place emergency procedures to be activated in the time between contingency plan and delivery

6. Make the big decisions about future infrastructure required to support “growth” safely and properly - and with it the costs they attract

7. Explain it to the town and LISTEN to public reaction

8. Imorove the go forward plan - get public approval

9. Seek funding for the future plan - MPs - government agencies - developers

10. Report progress regularly to the town

Nothing especially wrong with anything he says but looks a bit like a box ticking exercise that could go on forever. If this was China, there’d be people out there right now digging and moving earth by hand to get the job finished before we could even agree when to start talks.

 

Bill 😊

[asperity]

11. Make sure my 10% is ring-fenced.

[Observer II]

Perhaps subsidised loft conversions might help, then we could all abandon the ground floor and use it to garage the boat ? !     😉