Friday, November 30, 2012
Henry the Green Engine
Winter has now begun and birds various have flocked to the valley. Hundreds of Pigeons are hammering the rape in the adjoining fields and the jolly farmer has deemed it necessary to scatter pigeon bangers across the parish, which won’t do much for the neighbouring Partridge shoot. Fifty odd Greylags make regular sorties along the river line and the afternoon trees play host to hundreds of Finches and Siskin. On the radio the perennial Metro Sexual Tit has put in an appearance, garnered with an O level in hyperbola he declared on the lunch time news that the country was in the grip of a nationwide flood crisis, implying that survival was not a “given”. After retrieving my sandwiches from where they had been thrown an “angry from Bransbury” email was fired off to the radio station concerned.
Pictures on the left should countenance any fears of impending doom. This river is barely flooding, there is plenty of space in the aquifer for many more weeks of rain, The amount of rain that we have received during November is nothing special and far from being the wettest winter month on record.
Some rivers have flooded, but some rivers are meant to flood. The Ouse will always break its banks as it passes through York, The Severn and upper Thames jump at the chance of letting it all hang out on pasture in the flood plain.
Up close and personal, the force of a river in flood is an impressive sight. Further forays in the name of further education, found child B and myself heading West on what used to be the Great Western Railway. Departing from Swindon to Cardiff on a cattle truck of a train we stood in the buffet car taking in the flooded fields and swollen rivers that passed by. After ten minutes Driver McGhyver announced that we would be taking a detour, there were puddles ahead and our journey would now take in the sights of Bristol and beyond. Ten minutes later we stopped in a tunnel. The “screaming oojahs” had passed through our house during the week and child B, already nervous at projected delays to his arrival for his interview was now going green and looking like he was about to redistribute his breakfast amongst the occupants of the crowded carriage. Further complications arose as we recalled Rev Awdry’s fable of Henry the Green engine who was bricked up because he didn’t want to come out in the rain, mental plans were made to abandon a day that was going from bad to worse, but thankfully after fifteen minutes our journey resumed, a direct result of a sound thrashing from the Fat Controller or puddles that had been mopped up, we shall never know, but we rattled into Cardiff to be met by torrential rain, eighty thousand rugby fans and a very impressive University.
On our return a day of rain had added colour to the river which had risen an inch and the puddles on the road were of a substantial size. Forty eight hours later the river had dropped an inch and had cleared enough to reveal trout spawning hard in the increased flow
and weed that was cut in October resuming its growth. A few dry frosty days and the river has crept up a tad as the latest deluge has worked its way down into the aquifer to increase the groundwater flow. Puddles lie through the wood and footprints and prod holes betray a few Woodcock that have moved into the woods in recent weeks. There are also a few Snipe about on the top water meadow making the most of the flashes and splashes and the Egret has returned to mooch about in the streams through the Mill house garden.
When the water is on the rise it becomes apparent that the folk who built and laid out this mill knew what they were about. A puddled channel, half a mile long and gun barrel straight bar a kink near the top, maintains a height of water in front of the house four feet above the natural level of the river to spin the wheel. It was dug by hand hundreds of years to drive a Mill that has stood in the water meadows on no foundations and not flooded in recent memory. The hatch in front of the house, installed in 1846 and a hatch at the top where the mill stream leaves the main riverl gives complete control over water levels and flow down the river and mill stream. The EU’s Water Framework Directive will recommend the removal of some hatches up and down the river, and in some cases the river will benefit, on this stretch of the Dever the removal of these two hatches would have a detrimental effect on the main river as most of the water would trundle down the man made channel. For ninety percent of the time we leave the hatch at the top open, with any surplus water pushing down the Mill stream, subsequently for much of the year the man made channel is too wide for the amount of water flowing down it, and deposition of silt occurs.
Over the years we have done our best to improve the Mill stream through the planting of marginals on both banks cutting back hedges and trees to allow light into the channel and introducing a few sexy wiggles on the way along with a series of casting platforms. This has speeded up the flow in the top two thirds of the channel, improved weed growth, fish habitat and biodiversity as a whole. Ducks in particular enjoy the sanctuary of the overgrown far bank.
The bottom third in front of the Mill is a typical piece of impounded stream, slow with silt, but not void of life. This is the only section that would benefit from the removal of the hatch in front of the house, it is man made and half of it has a concrete bottom, it never will be a classic piece of chalkstream so does it merit the attention of the chalkstream restoration squad? it is an impounded piece of water and has been for hundreds of years, alongside the need to maintain and improve chalkstream biodiversity runs a requirement to recognise the historical status of some of the sites on the chalkstreams, used correctly these two hatches give control over the water in the valley in the half mile immediately upstream, as they have done for hundreds of years.