Repairs to Hydro – August 2021

The Coanda screen across the weir has now had 7 years of operation. In 2014 Hurricane Bertha caused some damage that was not obvious at the time by flattening some of the curved stainless steel plates at the top of the screen. This meant that some of the water spilled over the weir without going through the screen, thus reducing the generator output particularly during higher flows. Subsequent spates have made the problem worse and KCDC agreed that 2 of the 6 sections of the screen  would be replaced by strengthened versions and the others would be repaired and strengthened as necessary.

The work was originally planned for 2020 but was delayed because of Covid. The recent dry weather and low water levels allowed phase1, the replacement of 2 screen sections, to be completed by the end of August.

All the work was done by volunteers, mainly over a period of 5 days. This included putting about 70 sand bags in place to prevent water flowing over the screen (and removing them afterwards when they were wet and a lot heavier!), grinding off  and replacing the bolts holding the screen in place, and working underneath in the screen sump.

Removing the Coanda screens on the weir
Fitting the first new Coanda screen.

The KCDC Paths group did the heavy lifting, many thanks to Sandy, Gus, Bob, Eric, Kenny and Kevin, and the “engineering” work was done by Alistair, Gilmour and Ian B. Special thanks once again to Bob for “volunteering” to get very wet working underneath the screen. The opportunity was also taken to pressure wash all of the existing sections and clean off accumulated slime.

Sand bags deployed to divert the river away from the screens during the works.
Wet sandbags being “removed” from the site after the repairs had been completed.

The hydro was back in operation for a few days but once again was stopped due to low water level in what has been a very dry summer. It restarted after the rain on the 8th of September.

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