Weir, art thou going? River improvements part III

Our posts here and here about the programme of improvements to the Claise basin described the achievements in our corner of the Aigronne valley, out of 77km of river bank works in the last three years.

Now operations have started on the section of the Claise between Le Grand Pressigny and Etableau. If you go down the rue des Réaux towards Abilly you will see, or rather you won't see, the familiar line of poplars screening the decaying former furniture factory building near the déchetterie.

Stumps, logs and branches next to the Iron Bridge

The trees that remain, apart from the big oak, are mostly small alders.

View towards the weir from the Iron Bridge. The house behind the high hedge to the right is for sale.

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See "Improving the Aigronne Part II" for a translation of the poster

Poplar is an excellent timber, widely used for construction throughout France, and good poplar wood is valuable. The tradition was, when a daughter was born, to plant a poplar plantation to pay for her dowry when she got married. But these trees were too far gone. The smaller notice describes how the trees will be disposed of. Given that a Prefectorial edict obliges the commune to do the work; that turning dead and fallen trees and branches into biomass is not easy to do cost-effectively; and that the cost of hiring the mulching equipment needed to compost the remains is beyond the resources of the town council, SARL ETREN is authorised to burn what it cannot turn into biomass.

The field behind the digger is scheduled as building plots

The poplars were rotting at the heart, potentially dangerous, and they had to go. The weir is in the background.

You can read the small poster if you can fly. But it's important!

Be that as it may, the poplars were in the way of the really big undertaking.   Under the European directive on water courses and La loi sur l’eau et les milieux aquatiques (LEMA), the commune has to remove (literally, to "suppress") the weir, and return the river to a semblance of its original state. Given that water mills have been in existence since classical times, we are talking prehistory here.

La Nouvelle République in its article of 22nd November 2014 describes the weir project thus:

in May 2015, the barrage will be removed and the bed of the Claise re-aligned, rebuilding part of the banks with rock, earth and pebbles, with the objective of reducing the width, giving back to the river an appearance of the original bed, permitting the water level to rise and restoring the rate of flow.

The weir from the town bridge

The weir was built in the 1970s to provide a swimming area and sustain the water level in periods of low water. It is now obsolete. Nobody wants to swim there: the water is dark and forbidding, the bottom is squidgy and covered with leathery, slippery poplar leaves, and there's a heated public swimming pool on the other side of town. La NR continues:

the prefectorial mandate governing the operation of the weir obliges the commune to keep it open for nine months of the year. This obligation has never been respected. The repeal of this mandate will require the community of communes of Touraine du Sud (CCTS) to remove the weir and return the site to a fit state. The CCTS's land management brief makes the work possible. A partnership with the region [Centre], the département [Indre et Loire] and the water agency [for the Loire and Brittany] allows the rehabilitation of the site to be incorporated in the restoration program. This new project will be 100% subsidised.

 See also the CCTS web site here and here.

Suppress the barrage? Sounds simple enough. No big deal. A bigger deal will be the heavy lorries thundering past carrying the "rock, earth and pebbles" to the site and thundering even louder as they return empty at top speed. A major issue will be disposing of the tonnes of concrete of the barrage itself and the spillway, and the unknown tonnage of silt (la vase) deposited behind the weir. Where will it go? How much is there? How many lorryloads?

And just what is meant by the river's original bed? When the ground is saturated, it is easy to trace old meanders of the Aigronne, for example in the fields south of Rivau. The Claise valley between le GP and Descartes opens out to become several kilometres wide, the site of a prehistoric swamp/lake bed. Watermills go back to the times of Alexander the Great; human life in the Aigronne and Claise valleys goes back to the Upper Palaeolithic, 350,000 years ago. How far back should we go in restoring the river to its "original state"?

For us, the biggest issue of all will be when the sights are turned on Richard's weir and sluice gate that direct  the Aigronne's flow into the bief that runs past our house and the Moulin de Favier. That weir has been there for at least two hundred years, and is shown on the Napoleonic cadastral map of 1812. The mills existed when the Cassini  maps were drawn in the 17th century, and, since La Forge was an undershot mill, there must have been a weir too. The Cassini map does not show such fine detail. The sluice is new (1980s) and was constructed along with the étang. It is left permanently open.

The Dechartes have a history of the Moulin de Favier going back to the 12th Century. The habitat supports at least one nationally proteced species - the water vole - and local rarities like the Large Pincertail dragonfly. We have a duty to preserve la patrimoine, be it history or nature. On the other hand, everyone has a right to clean water, including the migratory fish such as eels which are blocked by such barrages.. I'm not quite sure how turning our bief into a stagnant ditch full of mosquitos will improve the milieu aquatique.

And the history of Le Moulin de la Forge is a matter for another post.

Autumnal Gold

A picture post, thanks to Nature's way of getting rid of waste...

Golden Leaves
A Norway Maple at its very best.

All those lovely leaf colours we get in Autumn are the trees pumping waste products into the leaves before letting them fall... we then gather them up if they are in the garden and try and recreate what happens naturally in the woods... the manufacture of leaf mould... one of the best soil additives out.
It is all part of the Carbon Cycle...

A lone Field Maple...
glowing at the edge of the wood.

Autumn colour
Two yellow Field Maples and a very red Sumac give colour to this view.
[The evergreens provide contrast.]

Three Trees Four
Four [yes, four,] Norway Maples... but one has no leaves.

On Golden Pond
Just a bit of Photoshop fun...

So thank you Carbon Cycle for your Autumn glory!

I'm a Timberjack and I'm OK

Yesterday our skyline changed forever. 

The difference between the top picture and the ones beneath is a gap of four days!
And three hours work.... [The middle picture shows a tree falling.]

The wood crowning the hillside opposite the house is basically a plantation of Corsican pines (tall, very dark green) with a fringe of Scots pine (not quite so tall, lighter green with reddish bark), a little clump of Stone pine at one end and an under-storey of scrubby deciduous trees - hornbeam, cherry, oak, ash, etc). It's rich wildlife habitat, providing nest sites for many birds, including buzzard, and shelter for mammals such as fox, rabbit and roe deer. The wood has been hunted very thoroughly every weekend and jour ferié since the season began, including this Sunday when thick wet snow fell all day and all the hunters had to wear fluorescent orange jackets. Today we found out why.

Just before lunch, a tree muncher appeared, labelled 'Timberjack'. This is a big engine with balloon tyres and an arm that simultaneously supports, cuts, and trims a full-sized tree. Along with it came a white van. This being France, the two drivers went off for lunch. After lunch, they returned with a log grabber. This is another big engine with balloon tyres, but this time the arm is fitted with a grab almost as flexible as the tip of an elephant's trunk, and it sits on a very large log-basket indeed. Both the engines set off up the snow-covered field, carving two deep ruts into the winter wheat.

Abbateuse.... with the original skyline behind.

Soon trees were falling. The engines cut down and moved aside a couple of the deciduous trees, making themselves enough space to be able to get through to the real target - the Corsican pines. These began to fall one by one, the first machine trimming them to lengths of two or three metres and gradually disappearing into the wood. Daylight began to appear between the remaining trunks as the dark green puffs of the pinetops tumbled out of the sky. Then the second machine returned to stack the logs by the roadside. The driver used the grab first to lift the timber into neat stacks, separating obvious firewood from half-decent logs and - the longest ones - good timber. Logs whirled around and plonked into place like so many pencils. If a log wasn't quite in place, the driver folded the grab into a fist and tapped the end of it delicately until he was happy with it.

As the afternoon wore on, we spotted another party of cranes heading south. The log grabber returned again and again with more timber. As night fell the drivers simply turned on floodlights and carried on working. Today half the pines have gone - all those to the right of the ditch except the clump of stone pines. The men and their machines departed well before nightfall, job done, leaving a neat stack of logs on the roadside.

Forty years ago this task would have taken a dozen men a week, and undoubtedly a few injuries along the way. Now it takes two men and some technology supplied by the forestry arm of John Deere. The log muncher is an abbateuse and the grabber is a porteur forestier. A second hand abbateuse might set you back 80,000 euros.

There will be more about this method of forestry in a later post on Art en Saule