SCADA in control?

JOHN Dodwell appears to be promoting the hypothesis on Canal & River Trust's behalf that there is no need for lock keepers and lengthsmen because the SCADA system will control the water levels in our canals. Events clearly demonstrate this is not the case, writes Ralph Freeman.

We have had many instances of high water levels in pounds due to heavy rain of late; three in the Sandon to Aston Pound on the Trent & Mersey Canal in the last six months alone. It's not just high water levels that are a problem either.

During the summer I met a distraught hire boat crew that had struggled, due to empty pounds, (pictured) to get up the Tame Valley and Rushall Flights on the BCN. Is CaRT saying these things don't happen? Of course they do. The question is why?

More high levels at Aston

Having reported the latest high water incident at Aston Marina to CaRT on the afternoon of Friday 12th October, I received a call back from a CaRT representative Monday morning saying they 'Had had people out all weekend'.

This ties in with a report from a boater who said he arrived at Sandon Lock to find 'paddles up' and water being flushed through the lock. So why the need for manual intervention and weekend working if the SCADA system is in control?

Problem at Barton Turn Lock

It was when the bywash became blocked that the canal overflowed onto the adjacent road at Barton Turn Lock, then flooded a local resident's garage. British Waterways had received several calls from concerned boaters in Barton Turns Marina regarding very high water levels, but for whatever reason (it was the weekend?) it took the action of local residents and staff from Barton Marina to stabilise the situation on Sunday morning prior to the arrival of British Waterways staff later that day.

So why did the SCADA system, in which some appear to place so much faith, not prevent this from happening? There are several issues that may explain this:

The nearest SCADA box is at Wychnor (less than two miles away) but maybe it's primarily function is to measure flow and doesn't have a level sensor outside the lock itself? Otherwise why didn't it pick up the rising water level in the pound and raise an alarm? As far as I can see there is no SCADA unit at Barton Turns Lock to measure the water level there either.

The paddle just in front of the offside ground paddle at Wychnor has a notice on it describing it's function as water control. Note it is manually operated. In other words to change the amount of feed water entails someone visiting the site with a key for the padlock and a windless. Not exactly high tech in 2012 I would have thought?

To summarise then the SCADA system alone cannot stop water entering the Wychnor/Barton Turn pound. More importantly there is no remote controlled, powered sluice at Barton Lock either to dump excess water . So it would appear the 'Control' element (the C in SCADA) is missing!