Remember a few weeks back...?

Remember what the Delph looked like..?

Seen it lower, put it that way.

They were building an emergency flood barrier on the Bedford Bank at Welney. Now levels have returned more or less to normal. How it's going to impact on the fishing in future seasons remains to be seen.

Is silt slowly choking the system in the Fens?

Did the shrimp boats sit this high and dry in the Fisher Fleet at low tide a few years back..? I'm not so sure they did.

The tidal river's silting up so badly in Lynn that the council is looking to buy an amphibious vehicle to replace the ferry that runs from King Street to West Lynn.

The report to councillors makes quite interesting reading when it comes to the state of the Ouse - scroll down to the first agenda item here.

What's all this got to do with pike fishing, you might ask. Well the tidal Ouse is the end of a system of rivers and drains that stretches far inland. In recent years, siltation has caused problems in the Delph, when water wasn't cleared off the Washes because of the shrinking window when it could be run off via Welmore Sluice.

Reading between the lines regarding the recent renovation of the Relief Channel tail sluice, the Channel's going to be increasingly relied upon to discharge water, as it by-passes the silted up stretch of the tidal between Denver and Eau Brink. This could prove a blow to hopes that fishing on the Channel might improve once the gates were de-silted which allow the Ely Ouse to flow into the tidal between tides.

Things are changing fast out there. Not even the rain we've had over the wettest summer for nearly a century has been enough to scour the tidal. The tide comes in with more force than it goes out, meaning the flood brings in mud faster than the ebb can clear it.

Disaster might not be looming toworrow. But the tidal river governs how the entire system operates. And sooner or later, there's going to be a tipping point when it comes to actually getting water away. Take the new pumping station at St Germans, which can now move water out of the Middle Level  at all states of the tide.

This relieves the immediate risk from the Middle Level, but where does the water go against a rising tide - back upstream, adding to the problems of siltation upstream in the tidal, between St Germans and Denver.

This might make the Welney and Ouse Washes more prone to flooding - what they were designed to do, some will doubtless argue. But what happens as the tidal Ouse between Denver and Welmore becomes more silted, reducing the scope for clearing water off the Washes.

Click here for schematics which show how that part of the system works. See what I mean..?

Fens get off lightly - despite fish kill in the Delph

We've got off lightly this summer. Just imagine what the drought they were predicting a few short months ago would have done to some of our drains and rivers, caught in a perfect storm of farmers abstracting the maximum water to try and save their crops, as the system cried out for rain.

While water levels have recovered, there's water on the Ouse Washes where the recent heatwave's fueled an algal bloom and made sodden vegetation turn to rot.

Now that foul water's started to find its way into the Delph, where another crisis looms. EA workers saw dead and dying fish in the Delph around Welches Dam on Wednesday. They've heaved in peroxide and deployed aerators to try and boost oxygen levels. It looks like they've got there in the nick of time, but the devil's in the detail as they say.

For they reckon it's going to take another three weeks for the remaining water on the Ouse Washes to clear, meaning a lot more de-oxygenated water could find its way into the Delph. Both the Delph and neighbouring Old Bedford are prone to fish kills at this time of year.

So far, the Delph appears to be an isolated case - meaning the rest of the system may well survive what's likely to be a short-lived heatwave unscathed. Let's hope so, podnas.  

+++Click here for schematics and maps of the Bedford system.

Maps of the Old Bedford River and Delph

Here's a useful couple of schematics of the Old Bedford and the Delph, which shows how the system operates to allow excess water to collect on the Ouse Washes before it can be discharged out to sea via Welmore Sluice and the tidal Ouse.

This is one of the more vulnerable areas of the Fens, as far as the impacts of climate change and rising sea levels are concerned.

It's also likely to become one of the areas where pike fishing becomes more vulnerable in years to come, as conservation groups buy up areas of land to turn them into new wetland reserves, to replace threatened coastal habitats for wading birds.

For now, it remains one of the more challenging parts of the system, partly because of the impacts of siltation and periodic problems with brackish, turbid water being allowed into the lower reach of the Bedford to replenish levels for irrigation during dry summers, and occasional fish kills caused when the water "turns" after heavy rain, causing oxygen levels to crash.

Pike are mobile and seemingly in decline on both drains. A few big fish were caught last winter, from areas off the beaten track. But like many of the drains in this part of the Fens, those who were successful had to put a  lot of hours in and some long walks to find them.

They're still fascinating waters to fish, partly because both the Bedford and Delph were dug when the drainers first began to shape the Fens into the landscape we know 300 years later.

The map below gives a view of the Middle and South levels, bordered by Well Creek, the Ely Ouse and the Old West. It's perhaps no wonder where to start is the dilemma many pike anglers face as autumn nears.