Osney Lock: Colouring “management” 

by Will O’Sullivan, WSPM 2020-2021

Our focus was tested on Friday November 5th. My classmates and I stood next to the river Thames under leaves just beginning to turn for autumn. That day, there were reports about the unprecedented national case-count of Covid-19 (as passersby unmistakably gave us “the side-eye” for our large group) and the US presidential election was unfolding in a crawling photo-finish (news of which was blaring out of a nearby radio). In this momentous context, we shut it all out, knuckled down and delved into the subject of an Archimedes screw–driven hydropower project on west Oxford’s Osney island. My first question was ‘What is unique about this project?’ 

The idea initially came about in 2002 among some friends in The Punter, a pub a stone’s throw from the lock. Work began on the hydropower site in 2013 and electricity was first generated two years after that. All the hydro project’s investors are guaranteed (with some risk) a 4% return. The screw is quiet and the artificial reeds lining the fish pass allow them to rest as they swim freely upstream, a significant benefit for the river’s biodiversity and one that is shared by the Sandford hydro project a half hour’s cycle away. The electricity is sold to the nearby Environment Agency depot, and the excess is used to power households locally. The annual target production of 180 kWh is enough to power 2 million kettles. 

With so many benefits and, for an infrastructure project, a comparatively painless inception (let alone for a project without large corporate backing), the question evolved from ‘what is so unique about the project?’ to ‘why is the project so unique?’ 

Ali, the project’s manager, pointed to funding and careful management; he specifically mentioned that, without the government grant for sustainable technology funding that recently ceased, this kind of project will be impossible. The prohibitive costs of damming the river and building the concrete base would stymie any similar project before it started. Meanwhile, the community project’s collaboration with the Environment Agency ensured a regular buyer of the energy, as well as a collaborator in finely managing the conditions of the river to ensure the screw turns and the area benefits. Ali has an app on his phone that he can use to check the status of the plant remotely. 

— 

In the title of our Water Science, Policy and Management course, “management” can sometimes seem secondary in what’s already a mouthful. At best, it might be an afterthought to the clear battle-cries of “science” and “policy” and, at worst, a neutral way of what can be disastrous human intervention in environmental projects. 

But for me this excursion to Osney gave colour to the word “management”. 

A big factor in the Archimedes’ screw working is the “hydraulic head”: the distance between the elevation of the water when it enters and leaves the system. It’s an invisible, ambient factor that is nevertheless crucial in driving the huge, churning screw. (When rains fill nearby aquifers and the pool at the bottom of the screw, the river height below is raised, thereby decreasing the height difference from top to bottom. This has the consequence that, counter-intuitively, the screw doesn’t work as well in winter when the river is most full.) 

Here is a video of the hydraulic head:

I left the site feeling that management is just a name for the invisible human ingenuity and care that lies behind the physical aspects of water (the science) and the technical nous (the policy) in water projects. Much like the hydraulic “head”, it is the invisible force driving the whole system. For this small Archimedes screw and the largest dams in the world, everything depends on that care... 

…and also government grants. 

Thanks to Troy and Helen, our teachers, and to Ali Lloyd of Osney Lock Hydro, who led us through the hydropower project’s history and context.