WEIR WORK QUESTIONS: and the answers

The Environment Agency has caused some comment and speculation in the village in recent weeks by putting in several days of work on the weir and new fish passes, which were built three years ago at a cost of around £250,000.

The recent work included clearing out the special eel pass and scraping the face of the weir back to plain concrete.

The agency said on Friday it had no unforeseen problems and the work was scheduled maintenance.

A spokesperson said: “We improved the fish passage at Horrabridge Weir in 2014 by extending the existing flight of pools and adding an eel pass.

We routinely visit and maintain the site every two months during which the steep weir face and the granite on the smaller fish pass weir are cleaned of moss and weed growth so that our level measurements are accurate. This is standard practice at all gauging weirs. The fish and eel passes are also checked and cleared of debris and blockages.

“Once a year, the eel tiles are also removed and cleared of silt. This was done at Horrabridge on June 27.

Between sites visits we regularly check the river level data at Horrabridge to identify blockages across the weir crest. The weir and fish passes were last inspected on Monday, July 31 July. At that time we did not find any maintenance issues.”

This was an answer to local rumours that the weir has holes in its face where water spurts out when the flow is high. Some people allowed that the spurting could be caused by weed, however, and since the cleaning, the overflow appears to be smooth.

According to the EA, the cleaning was nothing to do with this speculation. It was all about getting more precise measurement of the flow in the Walkham – a fast indicator of conditions on Dartmoor – through sensors in the water, connected to a monitoring station in Weir Park.

In answer to further questions about the technical reasons for the work, the agency’s press office said on Friday night: “Weed growth can affect measurement at the weir by artificially raising the water level. Our water level measurement is taken at the crest of the weir and any weed growth at the crest can cause an increase in the water level and interfere with the smooth passage of water over the crest. We work to millimetre accuracy at our weirs, therefore even a small amount of weed growth can have a significant impact on our water level measurement.”

The statement added: “We always welcome any observations from the public, such as fish pass blockages, which can be reported via the Environment Agency Freephone environmental incident hotline 0800 80 70 60. “

So do we have any more observations? Comment by using the box below (ignore the question about “website” unless you have one) or by email to newsdesk@horrabridgetimes.net/

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Editor of The Horrabridge Times.