Hi, I have used two routes to view Alpha lake. The easiest to describe is the one you tried, coming South along the Saxon Shore way from the west end of Flamigo lake. I haven't been since last winter so things may have changed, but part way through the winter the collapsed path was repaired but the sign saying the path was closed wasn't moved. Even with the path collapsed you could with care still make your way along, particularly when the tide isn't high on the Thames. Worth a look, but you have to make your own judgement on how safe this is.
The other route, from the RSPB car park (or park just before the gate) walk back towards Buckland lake and turn right before Buckland lake towards Westcourt Farm. Take the signed public footpath through the farm, and bear right towards where the railway crosses the aggregates road ahead of you. It's worth scanning the marshes South of here. Where the railway crosses the road there is a footpath going right before you cross the railway which passes through hawthorn scrub between the railway on your left and aggregates site on your right. At the end of this you reach a concrete wall at which you turn left, following this obvious path to the river. Alpha pool is on your right. The lake and reeds on the south (left) side are worth checking (Bearded Tit). When you get to the river you have to cross a bit of a drainage area which is often wet and muddy, and can be tricky to cross, wellies recommended. The bay on the Thames at this point is worth checking for waders etc. You can then walk North on the Saxon Shore way, to view the west end of Alpha. Last year RN Grebe tended to be at the extreme West end, and often BN grebe close to the far East end, with Slav Grebe anywhere inbetween... if you go, please let me know how you get on, I hope to visit myself soon.
Happy birding, and take care whichever route you take, both can be muddy and slippery, Paul
