The motivation for this blog comes from the DRiPS committee’s anxiety about the removal of weirs on the Darent, particularly one of the biggest and most beautiful at Old Mill Close, Eynsford.

Many weirs, together with their sluices and clay bunds, form millheads which provided “water energy” for watermills. Most of those on the River Darent were originally constructed in the 17th century and are a permanent reminder of the valley’s industrial past. In fact they are valuable industrial archaeology.

Those wishing to remove them argue that they prevent fish migration, cause siltation due to a slowing down of the river’s velocity and usually have a shaded environment (eg high trees) often due to lack of bankside maintenance. DRiPS however believe that old millheads provide a diversity of habitats and hydraulic regimes which suit different forms of aquatic life. Members of the committee have seen many examples of devastating irreversible changes in other rivers.

Climate change, pollution and relentless abstraction mean that chalk streams everywhere are under stress. These make it more pressing for thorough analysis of all the issues involved. We believe more discussion and investigation is needed to find out in what respects weirs are an asset as well as a liability.

Our position as a committee is that we must ensure all future modifications to the Darent should improve the whole ecosystem’s resilience, with special reference to

• drought
• invasive species
• pollution, especially under low flows.
• the local food web
• human wellbeing.