Godwit were more likely to be Black-tailed?
Thanks for the update Steve. Why am I not surprised that the flume hasn't helped, I hope they have a plan B. I bet the river didn't even overflow it's bank or if it did then not by much. A high river shouldn't have caused any problem providing the outlet on North Pit is checked regularly.A picture of the new flume (channel restriction) in action and a couple of the potential consequences due to its location. Under today’s flood conditions the flume was generating about a 6-8 inches restriction ie water on the upstream side was generally 6-8 inches higher than it would be if the flume hadn’t been installed. This would be great if it held back water in the river but under today’s event the elevated upstream water level meant it filled the pool to the right of the Lookout. This in turn flooded straight into North Pit and thus in theory bypassing the flume. The levels on Jubilee Wetlands are the highest I’ve ever seen them so under last night’s conditions the flume has not been a success. Also the path to the hide and the pipe bridge was flooded by 6-8 inches making them only accessible with wellies and, possibly, without the flume then these may have remained dry. When I first heard about the flume I had assumed it would go as close to the river as possible and its throat width (narrowing) would be a lot narrower than has been installed – but what do I know. If this happens later in the season then yet again most nests will be lost.
ps - this is NOT a criticism of the RSPB as it's the EA who have dictated the flume dimension and location.
............ I bet the river didn't even overflow it's bank or if it did then not by much. A high river shouldn't have caused any problem providing the outlet on North Pit is checked regularly.
I wonder if anyone even goes to the North Pit outlet any more? I used to unblock any logjams myself before the RSPB stopped people going down there. It was like a waterfall through a big pipe and a drop of circa 6 feet to the next pool on private land, it may have been altered since?Geoff - You are correct. The river was/is some way off breaking its bank as the first picture. Levels are even higher on the reserve today although you can just about cross the pipe bridge. Hide path still under a few inches of water though. The second picture (North Pit from the 2 benches) just shows how high it is. The vegetation just sticking out the water on the left hand side is the strip of land that usually divides the west channel. The only island now visible is the long one and again I think that is only vegetation.
On Jubilee (3rd picture taken looking south from lookout path) then its just one pool with no islands or spits visible. Even the west scrape division bank has been breached and that is totally full again.
Perhaps the outlet from North Pit is blocked as this is usually the least affected pool as it generally runs out as fast as it runs in.
Steve
I wonder if anyone even goes to the North Pit outlet any more? I used to unblock any logjams myself before the RSPB stopped people going down there. It was like a waterfall through a big pipe and a drop of circa 6 feet to the next pool on private land, it may have been altered since?
Morning all, having read this discussion with interest I thought that it was worth me adding some information about the works recently completed at Middleton and the current flooding.
The channel restrictor is designed to reduce the impacts of modest river rises and low level flooding that occurs regularly throughout the year and can have impacts on the breeding season for ground nesters on the islands. As Middleton Lakes sits within the floodplain it will always flood at times of major flooding and the restrictor was not designed to stop those major inundations, in this instance the levels rise and overtop the structure (whilst also overtopping the spillways into the north pit as it has always done). To cut the wetlands off from the river would require major engineering and would not be permitted as it would increase flood risk downstream it would also reduce the quality of habitat as the movement of water in and out and the irregular water levels are actually beneficial to the many waders that use the dynamic edges.
To put the current flooding into context, around midnight on Friday the river reached its highest level in five years and this surge is what caused most of the inundation that we now see. Its normal level at the measuring point is between 30cm in dry conditions and 80cm after rain. That surge overnight on Friday night pushed it to 1.4m. The ongoing wet conditions and the saturated ground means that the water heads straight for the river and the lower Tame is one of the first places that it can spill its banks.
We will only know how the restrictor performs in more modest river rises and hopefully this current flooding will be a thing of the past once we move into the breeding season proper.
For any other information or if you have questions, please don't ever hesitate to email me [email protected]
Cheers,
Nick