Thanks to volunteer Phil for his report and photos
When I first started volunteering here in Autumn 2014 the great floods of winter 2013-14 were fresh in people’s memories, and I learned that the whole of the brooks had been under water for about 2 months. The stories emphasised the fact that much of the reserve is part of the flood plain of the River Arun, but has some protection from a flood bank running by the river. I subsequently learned that there is a small tributary river – the Stor - which runs along the North side of the brooks not far from Pulborough itself and like the Arun it has flood banks on either side to mitigate the flood risk. In that very wet winter in the lead up to Christmas the amount of water coming downstream combined with the tidal flow upstream had caused the river to overtop the flood banks and left the whole of the low-lying part of the reserve under water.
So far, this autumn and early winter has been very wet and I experienced the effect of this on Monday 16 during the monthly Wetland Bird Survey (WeBS) when my South Brooks team was unable to reach the river bank from which we normally survey as part of the route. All 3 ways of reaching the bank were impassable due to high water levels, so on reflection it is not so surprising that one bout of heavy rain during the night of 19-20 December tipped the situation over the edge.
I left home on Friday 20 in light rain blissfully unaware of what had happened and what was to come. After a few miles and a car radio report announcing the closure of important road and rail links I encountered my first of many floods on the road, and was delayed in some places by slow moving traffic trying to avoid the water.
Arriving at Pulborough Brooks I was greeted with “have you brought your waders”, and invited to survey the South Brooks from the Visitor Centre window where something rather like a weir could be seen on the riverbank with water pouring vigorously over the edge and onto the Brooks. This photo of the “weir” was taken later from West Mead hide.
I decided to make straight for Nettley’s Hide as this was thought to be at most risk of flooding based on past experience. Arriving there it was very clear that there was a lot more water than there had been the previous week, but it was still possible to make out narrow strips of land on one of which was a flock of several hundred black tailed godwits. Further out it was very evident that the Stor was also overtopping its flood bank. This photo shows the water pouring over the bank and one end of “Black Tailed Godwit Island”.
For the next hour and a half there was no significant change and I compiled a good list of birds for the whiteboard in the hide. Perhaps the best sighting was a water rail crossing the ditch in front of the hide. A little further out a patch of brown reed stems was holding at least 2 snipe. Up at the Hanger my colleague John reported 2 white fronted geese in the distance at the foot of the Stor flood bank in a place where no water was coming over the top.
With the sun now out there were some good winter views.
After a splendid team Christmas lunch in the café I decided there was just time to do a circuit of the reserve before dusk to survey the state of the flood. At West Mead the pool had not yet joined up with any of the other flood water but the fine afternoon with distant showers was providing a good cloudscape.
The pool at Winpenny was also still separate, albeit much fuller than usual, but the hide had the distinct feeling of being right on the edge of the main flood
From Adder Alley I took a short detour to the Wetland Discovery Zone viewpoint to discover the bridge and gate onto the brooks to be inundated, and the dipping platforms fully submerged.
At the bottom of the Pig Run I found the footpath to the riverbank completely under water and couldn’t reach the gate to get on to it.
I had already been advised by a colleague that Black Tailed Godwit Island had completely disappeared, and I had already noticed several groups of black tailed godwits flying around, perhaps seeking some remaining land or shallower water. However, there was still one long narrow strip of grass to be seen where a large group of lapwings had settled.
From Jupps View I could see the Stor spilling over the bank on a much wider front than in the morning.
Nettley’s Hide was still accessible (I believe it had to be closed over the weekend) but in front the only sign of the ditch was the tops of the rushes fringing the bank.
The brown reed stems, now mostly submerged, held several more snipe than I’d seen earlier, still clinging on to the disappearing vegetation but probably not for much longer
For now, this flood presents quite a spectacle, and we may even see an influx of diving birds taking advantage of the deeper water, but for our wildlife overall this is not a good situation. The population of small mammals is likely to have been hit and this in turn will impact species such as kestrels and barn owls. The latter are known to have had a particularly bad time during the 2013-14 floods. The previous flood washed many unwanted fish such as carp over from the river which then took up residence in the ditches causing some disturbance to their ecosystem. This is likely to have happened again.
Over the weekend I have been checking the Environment Agency flood warning site for Pulborough Swan Bridge and, having peaked at midnight on Sunday 22nd, the river level has been slowing dropping. However the flood banks, which most of the time ensure there is not too much water will now be having the effect of keeping water on the reserve, and accessing the sluice gates to allow water to drain off when the river levels return to normal may be difficult. Our wardens may be facing a challenging few weeks.
Update for 28 December - the water levels have receded a little and all of the hides are now accessible but we'd suggest walking boots or wellingtons as there are muddy and soggy patches.
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