Work is continuing well to prepare for the arrival of our new eel-friendly bandscreen which is due to arrive on site on this coming Monday 23rd November. The structural platform is in place and the team are now carrying out electrical cabling and mechanical works to get everything in place for next week. In order to be sure that everything is ready, we will be taking the unusual step of working on site over this weekend for the first time. Our contractor IWS has assured us that there will be no heavy engineering work and will create minimal noise disturbance. The team will respect the fact that it is the weekend and a time of rest and relaxation for most people.
Thanks for your understanding as we near the completion of this upgrade project.
Activity at Waveney has been quiet in the last few weeks while the team were away working on our Belaugh site installing similar Eel protection screens there. That installation has gone really well and the team have transferred back to the Waveney, bringing with them the learnings and experience of Belaugh to make sure Waveney goes equally smoothly.
The dive team started on site last week moving any built up silt away from the intake in preparation for the screens and their supporting framework to be installed this week. Once that’s in the river the pipework and electrical connections will be made and if all goes well the system should be up and running by the beginning of December.
The Chelmer project had some minor associative works in plan before lockdown and in the last couple of months we've been addressing these so you may have seen occasional activity if you've been near the site. There are further works planned for November and some maintenance activities will also be carried out in the coming months.
The eel screens have been installed for a year and have been operating well. We’ve been asked lots of questions by interested passers-by so we're in the process of designing some interpretation boards to be placed on the site fencing and at the Museum of Power that will explain more about the purpose of the project and how the screens work. I've included a brief description below for anyone that's interested in how they operate.
In normal operation the screens are static, the fine mesh (2mm wide) allows water to pass through to the pumping station at Langford while 'filtering' out any debris and preventing small fish and eels from entering the pipeline. When the screens start to become blocked (e.g. if there is a lot of leaf debris or blanket weed in the river) they enter a cleaning mode where they start to rotate and wash water is sprayed from the inside of the screens outward to remove the debris from the screen. The debris and wash water drop into a trough behind the screens and return to the river downstream. If the river debris is low (as it is at the moment) the cleaning cycle will still operate every few hours to keep everything clear and prevent any build up. The screens will also run more often in the coldest weather to prevent any freezing up, so if you're passing site don't be surprised to hear them running frequently.
The screens were inspected by the EA recently and the installation has been accepted, so the eel screens should now be contributing to the wellbeing and biodiversity of this beautiful site!
The screens and infrastructure are now in place and the screens will be tested over the next few weeks while we optimise the cleaning cycle frequency. It’s the perfect time of year to be doing this, with most trees shedding their leaves now there’s plenty of debris in the water to give the screens a real test in the most trying conditions.
The attached photos are from the installation phase, you can see the mini crane used to lift the screens in and the dive team in the water carrying out the final fix. The screens themselves are totally submerged so what you can see above the water are the tops of the supporting framework and the floating boom which will maintain separation between the installation and passing river craft.
The team have worked really hard in some challenging weather conditions in the last few weeks and have taken care to smooth out any ruts caused by vehicles tracking across to the riverside site but there will be muddy patches left behind for a while in these wet conditions, please take care if you’re walking through the field. The grass should quickly return over these patches in the next growing season which will return the field to its normal condition.
I hope the summer months have been a tonic to everyone and that we have managed to enjoy as much of the outdoors as possible in these restricted times.
Work on site at the pumping station has continued and we now have all 4 new pumps installed and available to extract water. The first 2 pumps were commissioned at the end of May and went through a 28-day Reliability trial with very few issues. Subsequently, the remaining old pumps were removed along with all the old remaining ageing power transformers and switchgear. The second 2 new pumps were then installed and commissioned during the last week of September and these are now in their Reliabilty trial phase. During the commissioning period and despite the very low river levels, we managed briefly to prove that the new pumps could abstract the maximum licenced value of 164 Ml/d (million litres per day) of river water, probably the first time this has been achieved for very many years.
The next, and almost final, phase of work is to install our new "eel-friendly" intake bandscreen which as mentioned in my last report is required for us to comply with The Eels (England and Wales) Regulations 2009. Work will be starting in earnest on 26th October when we take delivery of the framework and control panel which will be assembled on site then lifted into position at the intake. There will be a 30/40 ton mobile crane on site for a couple of weeks while installation commences. The actual screen panel is due to arrive around the 3rd week of November and commissioning of the screen will start shortly afterwards.
As we enter 2021, most work will be complete and it is expected that our contractor IWS's site cabins will then be removed. There will be some additional work by ourselves to replace the old buried delivery line flowmeters within the site boundary sometime at the end of 2020/early 2021. This depends on component delivery times which are being delayed by world-wide Covid related issues.
Once again, should you have any queries or questions, please contact me via this portal.
We have a busy couple of weeks ahead of us with the divers coming to site late this week to install the screens into the river. There are likely to be a few more people on site than you may have previously noticed and with that in mind we'll be taking extra care to work within the government's construction guidelines for Covid-19 and keep distanced appropriately. With the additional activity you might notice a bit more noise during this period while the new screens and the wash system are being put through their paces but this will only be during normal working hours. I'll share some more photos of the site progress in my next update.
More good progress was made on site last week. The kiosk was installed first and the control equipment was placed inside on Friday. Electrical connections and testing will follow.
The infrastructure needs to be finished before the eel screens can be installed but if progress continues to remain on track the screens should be going in at the end of this month or early October. That activity will be weather-dependant as it will involve a dive team working in the river.
Feedback on the recent archaeological investigations has been received and it appears to be most likely that the flint wall was part of an old drainage wind pump, as the historical records suggested, although no dating material was recovered during the investigation to provide solid proof. Historic maps of 1879 and 1881 show a wind pump slightly to the east of the location of the wall but close enough that it may have been directly associated. The drainage pump did not feature on the 1905 OS map so it had likely disappeared long before the modern intake was created (approx. 1960s). The original Mill was probably similar to the Boardman's Drainage Pump, details of which can be viewed on Wikipedia at the address below:
Great day at the Waveney yesterday installing the new kiosk. It was another hot one but the work went really well. The photos show the crane manoeuvring the kiosk into place and its final position on the steel supporting framework. It's been raised off the ground to keep it clear of floodwaters.
The archaeologists are still working on their final report so I'll feedback on that once we receive it.
We've continued with the civils works on site, the piling went well and the steel framework to support the new kiosk is being manufactured so will be delivered to site soon. The same team are working on a related project on the River Waveney in Suffolk so across the two sites they've made really good progress.
The attached pictures show the recent piling activity in action.
The piling works went well, the framework for the new kiosk to sit on has been installed and the kiosk itself will be arriving on site this week. The site is really starting to come together. A few pictures below show the recent progress.