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3 hours ago, Murflynn said:

err   ..... what about the inflow from streams draining into the reservoir?  do you know the area of the catchment?  try repeating the calculation when you have that information to hand.

The main inflow from the catchment area is, or should be, able to be diverted by sluice gates. Were these working satisfactorily? 

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56 minutes ago, Richard10002 said:

I agree. What I don’t know, (but what somebody knows), is how and when the faster than usual rising water was spotted, and how and when the level reducing steps were first actioned.

 

If the actions started at their maximum as soon as the water started rising faster than normal, then fair enough. If they started after the overtopping began, or even when it became the torrent, then maybe something could have happened earlier or much earlier.

 

My perception is closer to the latter, but it’s obviously open to change.

I think, but am not entirely sure, that if the inflow sluices had been closed before, or even at the commencement of, the period of unprecedented heavy rain , the 'months worth of rain in 24 hours' would've raised the level of the reservoir by about the three or four inches which fell over the surface area. 

A few inches should not pose a problem as there should always be some headroom available.  

Was there any headroom available in the days prior to this event? How much? If not, why not?  

I am sure some of the many local users of the reservoir could answer at least some of these questions.

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29 minutes ago, Mike Todd said:

I seriously doubt that an on-site reservoir keeper would be allowed to clear such vegetation - needs a properly equipped team with safety harnesses etc.

 

Further, it is unlikely today that a resident reservoir keeper would be on duty 24/7/365 and my understanding is that matters came to a head rather quickly - no use having a resident if they are not there. Such cover requires at least a team of four, all fully trained and equipped. In today's context I would much rather go with having go remote monitoring and a very responsive command centre. Also, having a good water management model and system - again my guess, but I suspect that it will being having a significant update to the data at least for Toddbrook, if not for all CaRT reservoirs to give greater headroom without loss of service (more headroom means less capacity)

The previous on-site reservoir keeper had no need to deal with that type of vegetation, as it was dealt with before it got to that stage - safely and easily. Furthermore, long-term residents of WB  have been clear that seeing overtopping and use of the spillway was 'very rare' prior to 2012. Before forecast periods of heavy rain, the keeper  would use the sluices to divert the Todd Brook and other inflow, and lower the water level by use of what one person described as 'the gates at the bottom.'  Thus sufficient headroom was maintained -  enough, when necessary,  to cover for periods of heavy rain during the keepers absence and days off.

 

Since 2012,  several WB residents have contacted the CRT wrt their concerns about the changes they have observed on and around the dam. Their concerns have been dismissed and they have been told they were 'wrong'. 

 

Maybe they were, indeed, wrong, Maybe the breach would have happened even sooner, and more catastrophically, if the keeper had continued diligently keeping the spillway clear of weeds, maintaining appropriate  'headroom' below the spillway, and diverting the inflow according to water levels, expected demand and the weather forecast. Maybe not.

 

I don't know, do you? 

 

 

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1 hour ago, BruceinSanity said:

Like the one on the Boeing 737 MAX, you mean? ?

That  did come to mind, yes. 

Conversing with  BA Systems employees on the subject of the Boeing Max software has been ... interesting ...  And of course both merely, and highly, speculative. 

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7 minutes ago, PaulD said:

 I also assume today that all levels and functions can be monitored remotely from a control room so that people only need to attend if needed. 

Do you mean the sort of software that also detects risky situations, provides warning/alarms,  and maybe even 'takes over' in a perceived emergency? 

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18 minutes ago, Chewbacka said:

The only rare species that has been lost from the area is the dam keeper, I wonder if they did a risk analysis back then............

Good one!!

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1 hour ago, MoominPapa said:

There's Google streetview imagery from the top walkway showing some growth and dated 2014.

 

MP

The resident keeper was made redundant some time in 2012, though. 

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Are there any photos of the dam and spillway's condition in the years prior to the resident reservoir-keeper's redundancy? That might make an interesting comparison to more recent pics.

 

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55 minutes ago, Heartland said:

 

 

  This is the tip of the iceberg,  how many other roles have gone in the CRT in the 7 years since setting up. Whilst the Toodbrook Reservoir emergency was caused through heavy rain fall, it had been my belief, that key areas where staff maintained the dam, was a post that should not be removed as cost cutting. Had there been a member of staff there, the most severe damage could have been averted, but as previously stated only an inquiry will find the answers.

 

Meanwhile the threat continues ...

I  have been told that 'Kev' (the dam-keeper/overseer or whatever his title was) was meticulous in his observations 'on the ground' and would use all the means at his disposal to divert flow into the reservoir, and increase flow out of it, during periods of 'unusual' weather conditions. He did everything in his power to minimise or avoid use of the spillway. 

The frequency and volume of water flowing over the spillway - a rare event during the tenure of dam-keepers in the cottage - alarmed many regular observers in the area, but their concerns were pooh-poohed by CRT.  

I confess I am now wondering what - if anything - those dam-keepers had learned or grown to suspect, over the years, about the spillway's condition, construction or possible weaknesses. 

I  doubt any official enquiry will uncover that!

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Someone who lives in WB  has told me the following

The reason this has happened is neglect since BW was abolished by the govt and the Canal and River Trust took over without sufficient funding.

There used to be a BW employee living in a tied house right next to the dam;  he managed the reservoir on a daily basis, controlling the water levels with the side sluices and the gates at the bottom, so there was enough capacity to take extra in when necessary, without it getting to the point of flowing over the spillway which is only meant to happen as a 'last resort'.  This employee was made redundant when BW was abolished, and the house was sold.  Daily monitoring has thus been lacking for several years; visits and observations for brief periods a couple of times a week is no substitute  for daily active management of reservoir levels!  People in WB - some of whom knew the BW employee and had helped him in the past - have contacted the CRT over the years with concerns about  damage to the spillway when it was overflowing, but were basically told they were wrong. Now it is alarmingly clear that they were right.