Over the last few months, quite a few visitors have been surprised by how low the water level is, particularly in front of the Coffee Shop. As Sarah explained in an earlier blog, lowering the water level during the late summer and autumn is exactly what we want to do, so that we can provide lots of food in wet mud for migrating waders. While it looks low in front of the Coffee Shop, if you look at the same lagoon from the Boardwalk or Tal-y-fan Hide, you'll appreciate that it was absolutely perfect, and the diversity and numbers of waders here through August and September is testament to that. It was one of our best autumns for years, especially for Dunlins and Curlew Sandpipers.
But now most of the migrant waders have headed south to West Africa, we are bringing the water back up, by pumping between 200 and 400 cubic metres of water each day from the Afon Ganol (the stream at the south end of the reserve). We can pump only at low tide, otherwise the estuary water gets in the pump and the salt would kill much of the waterlife (such as dragonfly larvae) in the Bridge Pond, through which the water is routed when we are topping up the Shallow Lagoon. And we can only pump from the Afon Ganol following rain above Colwyn Bay; after a few days of dry weather there isn't enough water in the Ganol.
By having a 'full' lagoon in the winter, there'll be plenty of room for 'drawdown' next summer. We have very limited control of what goes in and out of the lagoons. Aside from the pump, we rely on rain that falls directly on the reserve (there are no streams or rivers running into the lagoons). Water levels fall in the summer through evaporation and being sucked up by the reeds. It can go down by a centimetre every day (that's nearly three inches a week) if the sun is shining and it doesn't rain.
This limited control isn't ideal when we want to make the best homes for nature, so we are investigating how we might move water between the two lagoons, and how we can further improve the feeding habitat in both lagoons. The Conwy Support Group's fundraising efforts at the moment are aimed at this, and we hope to have more news on this over the winter.
Meanwhile, back to this week. The plants still think it's early autumn, with lots of blackberries still on the bushes, and numerous flowers still out. Small tortoiseshell and red admiral butterflies have been on the wing, and common darter dragonflies were busy egg-laying in our ponds until a few days ago, though the weekend winds have limited sightings. Fungi are popping up in lots of places, even using the Discovery Trail post by the Bridge Pond as a growing medium! But there are signs of winter: two whooper swans yesterday morning (26th), more sightings of water rails (the Boardwalk screen seems particularly good at the moment), and up to four pintails have been present all week.
Around 50 snipe were counted yesterday (26th), while last weekend's Wetland Bird Survey included 247 teal, 482 redshanks, 12 bar-tailed godwits and 53 dunlins. A red kite was seen from the Coffee Shop on Monday (21st), redpoll and siskin on Tuesday (22nd), skylark and a mixed flock of 2500 thrushes on Thursday (24th). What will today's winds bring? Perhaps a grey phalarope, or the reserve's first Sabine's gull?
Julian HughesSite Manager, Conwy