The summit water problems

HAVING descended from the Tring summit [Grand Union Canal] last week (when it was definitely navigable) I can add to your information that CaRT were pumping water from the Cowroast borehole to feed the summit pound, writes Neil Quarmby.

The reservoirs at the Tring summit are primarily groundwater fed (from the Wendover springs) as are the two boreholes at Cowroast and Northchurch.

Notably low rainfall

EA report that following 12 months of ‘notably low’ rainfall, groundwater levels are below normal and some sites in the Chilterns exceptionally so. You can see this in the rivers. The Bourne at Berkhamsted is dry except for a short while following a decent rainfall event. The Gade has barely any flow too.

Both of these, along with the Colne, feed the GU south of the Tring summit. The Lee, which also rises in the Chilterns, has recorded its lowest November flow at Fieldes Weir since 1945.

Much depleted

The fact is that there is a shortage of water and even if the above ground supplies at the summit reservoirs appear to be getting back to normal winter levels (56% capacity in mid December according to CaRT’s reservoir watch even after a month of navigation restrictions), the underground reservoirs, upon which the canal also depends, are very much depleted.