Sunday, August 19, 2012
Tides govern drains and rivers in the Fens
I have a theory the tides are going to play more of a part in pike fishing than they have for a few seasons right from the word go this autumn. The simple reason for this is that water from brim-full main drains and rivers is currently being pumped off or discharged between low tides.
The impact that this has, even miles inland, is that it brings some flow to the water. A few days ago, the bottom end of the Middle Level Drain was covered with azolla. Seeing a picture of it on Twitter, I took a detour to get a picture of it yesterday only to find it had almost disappeared - pumped off via the new pumping station at St Germans into the tidal Ouse.
The pumping station's not the only change on the Middle Level system. The sluice under the aqueduct at Mullicourt has now been removed, meaning when the pumps are running, the whole system's going to flow as far inland as the Sixteen Foot, Forty Foot, Popham's Eau and the Old Nene.
Tides govern the pumping regime, because it's cheaper to pump water at low tide than against the tide. One of this season's projects is to make a note of what the tides are doing before I go, to see how they impact on flows.
I know there are people who swear by moon phases. One thing the moon phase determines is the size of the tides, as they cycle between springs and neaps.
All that water, from the Ouse and its feeder rivers, to the main drains and the man-made sprawl of waterways that feed them, is connected. Fascinating place the Fens.
posted at 13:57