Hydro Articles

Hazel nuts eaten by dormice


Posted in Hydro on Wednesday 24th October 2018 at 12:56pm

One of the warm and fuzzy stories of Old Walls Hydro was the arboreal link we had to maintain as part of our planning permission to ensure the future family connections for dormice across the leat. We have many sections of our woodland that is rich in Hazel trees and coppiced hazel which produce copious amounts of hazel nuts. The nuts prove very popular for both dormice and squirrels amongst other creatures. In the picture there are hazel nuts newly fallen from the tree which are whole; others crunched open with abandon, evidence of hungry squirrels and lastly, tidily opened nuts left from the dormice. The hole excavated by the dormice is circular with a smooth inner rim and if you look really closely you can see the teeth marks running at an angle to the hole. Old Walls dormice are obviously thriving!

leat trimmiing

Leat trimming

Leat maintenance

Posted in Hydro on Friday 29th June 2018 at 10:50am

Who said work couldn’t be fun? While leading our guided walks we often get asked about what maintenance we have to do on the leat. The vegetation on the leat sides have naturally grown to be an annual job. To stop the trailing brambles and ferns blocking the flow of organic debris to continue its way down the leat to the screener, we must trim the edges back once during the summer and cut them back properly later in the year. The picture shows how we use our little row boat to travel up the leat with our outboard electric motor and trim the far bank of the leat sides with hand tools. It becomes a great family affair with the grandchildren helping while they learn how to control the boat – needless to say Grampy did end up in the foliage once or twice!

Kelt protection

Kelt protection

Posted in Hydro on Saturday 3rd February 2018 at 5:48pm

Following the life cycle of the salmon that run up the West Webburn we have just completed our Kelt protection. The adult salmon run up the river to spawn above us, I have mentioned our fish wheel in a previous news article, protecting them on the way up. On the way back down the river after spawning about 5% will live to get back to sea the remainder will die naturally. To help the 5% we have a static grid which stops the kelts entering our leat and therefore ensures they travel past our system by swimming over the weir to continue their journey to the River Dart and eventually Dartmouth. This year we were actually able to show a visiting group how it works – not many folk choose to visit in cold, wet, windy January!

Our Generator Community

Posted in Hydro on Wednesday 13th December 2017 at 1:23pm

Fish Wheel

Fish Wheel

Posted in Hydro on Tuesday 24th October 2017 at 11:39am

The seasons seem to roll around faster than ever, and earlier this month it was time again to put our fish protection in place for the adult salmon that are about to start running up the river to spawn. Often folk ask us how we fit the fish wheel in place and the picture illustrates how with the help of the digger we can safely fit the wheel in its channels in the tail race without putting anyone at risk. It is also pleasing to know that a few weeks after fitting the fish wheel Miles has already seen salmon not only above our powerhouse but also above our weir this season.

New generator

Lightning strikes!

Posted in Hydro on Wednesday 30th November 2016 at 12:26pm

Just over a week ago we had a terrific thunder storm, short lived but destructive. I managed to disconnect all my communication equipment phones, computer, printer/scanner, tv etc after the first bump of thunder. Just as well because just a few minutes later about 11pm an almighty clap of thunder followed very rapidly by a powerful strike of lightening caused havoc around and about. We didn’t come away unscathed. Our deep freeze “died”, the hydro’s screener battery charger had a similar fate but the major damage was done to our big generator in the powerhouse. The smoke that poured out of it was a bit of a giveaway! Miles being ever resourceful had taken out the damaged one and fitted the replacement (which he keeps on the shelf all 530 kilos) and we were up and generating again within 48 hours!

Weir maintenance

Weir maintenance

Posted in Hydro on Thursday 28th July 2016 at 12:03pm

During the last couple of months, we have had surprisingly little rain – real rain, Dartmoor rain. Yes, we have had drizzle, mizzle and the odd thunder shower that lasted maybe half an hour but none of our real prolonged heavy rain that we are used to. In the summer months it can be of benefit to us as it is this year. The river is so low that we have been able to channel all the river water through big 4-inch syphon pipes and two pumps to dry up the area around our weir. We have been able to do some major maintenance work safely, for us and the river creatures, on the weir. This is the first major work on the weir since its construction in 1995.

Autumn leaves in leat

Autumn leaves

Posted in Hydro on Friday 6th November 2015 at 12:22pm

The new screener controls have been put through there paces over the last few days while autumn leaves are blown off the trees in vast quantities. Our leaf mould pile is growing daily and will provide some good soil conditioning compost for the fields in a couple of years and all for free!  

Sceener cabinet

Screener upgrade

Posted in Hydro on Friday 30th October 2015 at 8:56pm

After such a difficult year for the family with loosing Miles’s mum and Gail having breast cancer at last Miles has had time to get back to upgrading the screener controls. He has built a brand new home for all the switches, circuit board, batteries and pipes needed to operate the automatic screener efficiently. It is primarily created of concrete which is flood proof so if ever the conditions get so bad the leat overflowed at the forebay the electrics will be safe – with the climate changing you never know when the next flood warning is coming. Grand-dad also had time to show the grandchildren how it all worked.

Image result for goosander

Wildlife on the river

Posted in Hydro on Sunday 10th May 2015 at 10:46pm

We have just seen the beautiful little dipper flying out from under the powerhouse on a fishing trip, obviously nesting again under the floor above the white water that leaves the turbines. Look up and the heron will not be far away on the river patiently waiting for his next meal. Observe from a distance and watch the pair of goosanders scim the surface of the river until they see a fish and then efficiently dive for their quarry.  Walk along by the water in the moonlight and catch a glimpse of the otters once again fishing the West Webburn after a lengthy absence. With all this hunting going on providing nourishment for the natural wildlife it is clear we have an abundance of fish this spring in the river. Something we and our EA contact can verify when we recently, on three occasions, counted over a hundred salmon and sea trout smolts in our leat just before we released them down our “fish pipe” to continue their journey to the sea.

Autumn leaves

Autumn harvest

Posted in Hydro on Thursday 27th November 2014 at 12:59pm

This is the time of year when we start to harvest the beginnings of our wonderful soil conditioner – leaf mould. As the autumn colours arrive so does the inevitable fall of leaves from the trees. Many of these end up in the rivers especially after heavy rainfall having been washed off paths and roads into the waterways. As we have 10ml screening at the end of our leat we collect a massive amount of leaves each autumn. We are about three quarters of the way through the fall of leaves this year with most ash, cherry, beech and hazel trees already bare. Another couple of good frosts will see most of the remaining leaves fall, mostly oak. We pile up the leaves and let them rot down over the next year. Next September we turn the pile of partially rotted leaves just before we start collecting again. After two years of composting down we have the most wonderful leaf mould soil conditioner which benefits our farm fields. Natural recycling at its best!

Cink turbine

Maintenance time

Posted in Hydro on Sunday 31st August 2014 at 1:20pm

In 1996 we fitted our Cink turbine and it has successfully been working to produce electricity ever since. Apart from everyday maintenance e.g. greasing and one bearing replacement it has never let us down. During this summer the rivers have been very low so we decided to finally take the turbine out and have a look at how it had faired. The picture shows the farm tractor slowly edging it out of the power house after we first removed the side wall completely.

Transition piece and draft tube

Maintenance time

Posted in Hydro on Sunday 31st August 2014 at 1:19pm

This picture shows the hole left by removing the turbine. The draft tube can be seen below where the water flows back to the river after it has been through the turbine and the pipe suspended above is the transition piece which turns the round pipe into a rectangular pipe which fits the turbine inlet that you can see on the photo of the turbine above. We have since taken out the transition piece as it is much easier to clean it up and repaint it in the workshop.

High water - weir

The rivers are full again

Posted in Hydro on Thursday 31st October 2013 at 6:42pm

What a difference a few weeks makes. Not only is the leat full but we are back on full power with water to spare. The fish wheel is back in place, in the tail race, to protect the adult salmon and sea trout as they progress up the West Webburn to their spawning grounds. The automatic screener at the end of the leat is on over time with the autumn leaves beginning to fall from the trees in their thousands every time we get a “good blow”. We have certainly had our fair share this last week with the storm named St Jude passing over us. We have had no major structural damage, a large branch falling on the garage put a dent in its roof and several other limbs have broken off trees but caused no serious harm.

Empty leat

Leat maintenance

Posted in Hydro on Wednesday 11th September 2013 at 12:26pm

Following this very dry summer we have made good use of the low river levels to do as much leat maintenance as possible while minimising the loss of potential electricity generation. 

The first, entertaining but time consuming, job to be done before we can work on an empty leat is to collect all the brown trout that usually live in our leat and pop them back into the river. This is a game of speed and skill like big kids fishing in the stream with big fishing nets! To do this we lower the water level so we can work with waders on to hand net the fish and transport them in buckets of clean water to the river. Once the leat is fish free we can pump out all the pools of water to work on a dry bed. We deal with any leaks that may have occurred in the bank, hand pull all the weed that has started to grow in the bottom of the leat and trim the vegetation along the top edge of the banks. We work as quickly and efficiently as we can to reduce the days it is empty and this year to ensure the leat is full of water for our next guided walk tonight!

Visitor Comments

Posted in Hydro on Wednesday 1st May 2013 at 5:19pm

Some quotes from a recent visit to our hydro power scheme from a local amenity group:

“Carol and I were amazed at your hard work and enterprise on you hydro-power scheme!”

“Really great, very interesting and inspiring.”

“I must really congratulate you on your engineering achievements…”

“We all enjoyed your very informative descriptions and walk through your delightful location.”

Salmon are thriving

Salmon are thriving

Posted in Hydro on Sunday 31st March 2013 at 11:48pm

It’s good to see evidence that salmon are thriving on our river, theWest Webburn. A previous article I wrote told the story of the salmon smolts travelling successfully past our hydro scheme to continue their journey to the sea. During this winter we found a dead Kelt upstream of our system which measured 33” long. It is very pleasing to know that these magnificent creatures have managed to complete their journey fromDartmouth, despite the fishing lines. This is clear proof that they are reaching their chosen destination and are able to spawn successfully in the upper reaches of theWest Webburn.

Webburn full

Truly awesome renewable energy!

Posted in Hydro on Friday 1st February 2013 at 5:53pm

Just like everyone else we have been dealing with the excess of water everywhere – on the farm, around our home and yes even with the hydro electric scheme. For the latter we have been monitoring, very closely, the high water levels in the run off periods after the very heavy downpours. The effect on the river is very fast and it can easily catch you out and over top the leat bank if we don’t manually restrict the flood waters with our sluice gate at the intake. The power house end can still be excessively high as you can see from the picture. The tail race is underwater on the downstream side and the arch way beneath the powerhouse is full - compare it to the picture on the About Us page.

Fish wheel in tailrace

Summer generation

Posted in Hydro on Saturday 25th August 2012 at 1:29pm

What a different year this has been for generating electricity. We have rarely had to use our small turbine as the river has hardly ever dropped to what is normally consider summer flow levels since March’s heat-wave! Apart from generating all that renewable energy the flow levels have obviously had an effect on the river’s inhabitants. We have already put our fish wheel in to guide the adult salmon past us as they travel up to the head waters to spawn. The beginning of August is really early for this stretch of river to have salmon and sea trout running, but they are there, and going past us safely in the heavy fast flowing river water.

Turbines fully open

Posted in Hydro on Wednesday 25th April 2012 at 6:18pm

We often loose out on one enterprise only to gain on another. The cows may still be in their winter housing but our hydro electric production has steadily risen to full power as the rain has continued to fall with surplus water tumbling over the weir and spillway at the intake. At the forebay I watch the screener being triggered regularly by the debris being carried in the storm water, and, as I sit at my computer writing this I spy the heron visiting in case he has the opportunity to take a fish or two. He leaves after a few minutes without his tea (our protection is obviously working) then I look up and see a majestic buzzard circling overhead. What an office to work from!

Rain at last

Posted in Hydro on Tuesday 10th April 2012 at 5:15pm

With our “hydro” hats on we were very pleased to see the rains come over the Easter weekend. The West Webburn was running at a low summer flow level until yesterday. Although most of the rain has been taken up by the very dry soils (good for our farming!) there was some surplus that made its way to the rivers. For about 12 hours the river was running at normal winter flows rates. However, it has settled back now and is producing electricity at about 18% production, still way below where we would expect it to be but better than before Monday’s rain. It also brought another wave of smolts down stream and we again left our fish pipe open all night. This morning they have all moved on beyond us on their journey to the sea.

Smolt migration

Posted in Hydro on Monday 26th March 2012 at 12:12pm

Yet more evidence that the weather is behaving in a very unseasonable way – the smolts are running. Over the weekend we noticed salmon smolts in our leat and by Sunday morning they were in the forebay. This is the earliest we have seen them “run to the sea” since we built the hydro scheme. Maybe the migration is due to the warm weather or perhaps the summer river levels? Whatever the reason we had the fish pipe open for 24 hours and they have all successfully continued their journey past us. Let’s hope in 2 or more years time they will be back in the rivers to spawn and start the species life cycle again.