April 2024

My bird count was on the 16th. The news was a pair of Mandarin Ducks beside the new course of the brook beside the toilet block. Subsequently, park users have reported three of them on the lake. This is a feral species (established in the wild but of captive origin). It nests in trees and is probably considering breeding in the nearby Ashen Grove Wood. It's found regularly in other nearby sites, such as the water bodies on the commons, so its arrival is no surprise. It was a quiet time for the birds of the lake. On the lake, coots were sitting on eggs, with one nest on the canoeing rafts, at risk of disturbance. There was a single Grey Heron on its nest in the Evergreen Oak on the island. The Mute Swan was still on its nest on the Wimbledon Club lakeside. Another nice record was a Garden Warbler singing in the hedge between the tennis courts and the tube line. There was quite a lot of social interaction with other birds there, so possibly a breeding territory, but I suspect the birds were on passage to better habitat elsewhere. More prosaic was the usual Spring Chiffchaff singing in Horse Close Wood and Blackcaps also singing there, in Ashen Grove Wood and in the northern hedgerow bordering on the ex-golf course.

The native Bluebells in Horse Close Wood were in flower. Sadly, the main concentration was harmed by trampling when big numbers went through there in Covid times, but there is a good scattering of survivors. There were many hybrid (non-native) bluebells also in the wood, and elsewhere in the park, including on the downslope of the dam and beside the path through the bowls area.

The future of the waterfall is being considered. Sadly, the landscaping has fallen into disrepair and there is a leak in the base of one of the basins, so it would be a big project to fix it. Some believe that the water supply from the lake is compromised, but I don't think so. The inlet from the lake is low enough, even when drought lowers the lake level the flow continues, but the debris screen there is a poor design and needs frequent clearance. This used to be a routine operation by parks maintenance people. A better screen would be a simple project, but fixing the landscaping around the waterfall itself is a much bigger job. Children used to really enjoy informal play in the waterfall, despite the advice to keep out! There is potential further downstream in the brook for informal play, but the only easy access is to the old stretch of the brook from the toilet block down to the water garden. Some of the planting around the waterfall survives. There are six Trachycarpus palms, but just the one struggling Dicksonia antartica tree-fern.

One-by-one the old arboretum planting is succumbing from competition and old age. The latest casualty was a Tulip Tree Liriodendron tulipifera on the dam downslope close to the Bowls depot. Its potential as an informal playspace was discouraged by it being taped off.

The old drain that gets its flow from Home Park Road and that emerges beside the toilet block had milky water. I saw just the same a year or so back and had an unpleasant experience when I reported the obvious pollution to Thames Water as one is supposed to do. Thames Water were reluctant to turn out until I pointed out the guidance to them. The investigation team didn't turn up for two hours and expected me to attend promptly, but by then the flow was clear. They were reluctant to talk to me about it, relying upon their own observations, after the event! I urged them to take my photographs as evidence of the incident, but they refused! I presume this one has been recorded as non-pollution in their statistics, if at all. So, this time I didn't bother. I didn't want another long wait followed by a high-handed dismissal.

Some time back, the old pipe which took the lake outflow underground to emerge at the toilet block was re-opened at its upper end within Ashen Grove Wood. Since then much of the outflow came that way rather than down the new course of the brook. Now, however, the predictable is happening and the entrance to the pipe is becomming clogged with debris, as there is no grille to screen this pipe entrance. This even threatens to compromise the flows from the Home Park Road surface water drainage, as it joins the pipe underground. If this happens, expect the storm flows to emerge at the man-holes and an accidental return to the channel that used to flow there before the children's play area was created. Old-timers recall playing in it!

I did the lake water sampling on the 30th. The water clarity was good, as is usual at this time of year, but there was very little sign of water weed, just a few whispy fragments of Fennel Pondweed, and the blue-green Aphanizomenon flos-cuculae was visible to the naked eye: looking like tiny fragments of lawn cuttings. So, there is a looming risk from toxicity as sunlight and water temperatures increase. Whilst that is a different species of blue-green than the one that left a dog crippled last year, the official advice is to avoid contact with Aphanizomenon. I will tell Merton, but I fear that park users have become accustomed to the warning notices and that nothing extra will be done.

An attempt to assist drainage of the Great Field was seen. Tines had been towed behind a tractor to disturb the soil, I would expect without much effect. This is because such underground disturbance is supposed to provide for drainage of saturated soils into a deep subsoil with free drainage. Here, however, the soil has a high content of silts and clays, giving even the subsoil a heavy, poor-draining structure. Another counter to drainage is that heavy traffic should be avoided over loosened soils, as re-compaction can be worse than the original! What did I see? - regular traffic by the park runabouts and compaction by the use of tractors in setting up Zippo's Circus.

Park management is compromising people's enjoyment of wildflowers. The crazy golf rectangle has been mown without raking off the resulting thatch, so beheading and supressing wildflowers. It would be easy to mow just around the golf plots to allow ready access, and to extend this to the brook edges if concerned with safety, but it's edge to edge. Allowing those other areas to grow tall would enable people to enjoy quite a nice meadow. This attracted praise from users of the facility last year. It's not too late to do this. Sadly, the tiny area of grassland between the tennis courts and the paths to the Home Park Road steps has been mown, so breaking the long standing agreement to leave this to grow for the Cuckoo Flowers, Germander Speedwell, etc. Drastic clearance of colonising vegetation has taken place below the athletics area hedges for no obvious reason. The many interesting wildflowers that have thrived there before have been set back, even compromising Elder, Yew and White Bryony. This area would become an interesting hedge bottom flora if given a chance. Instead, those many people who pass by on the adjacent perimeter pathway have nothing to look at but the ugly, bare lower trunks of the Leyland's Cypress. 

After a wet Spring there was still standing water in several places, showing where it would be possible to create wildlife ponds. Water was still flowing over the perimeter path at the northern edge of the athletics area and within the hedgerow not far south of where the brook leaves the park. Two areas of ponding are the result of the National Grid works to remove their cables: one in the Lofthouse Glads and the other at the edge of the Great Field nearby.

Work was under way providing steps down to the new course of the brook either side of the tunnel between the two grilles near the cafe. I was told that this was for access to the brook so that accumulated debris could be removed. That's a puzzle, as such clearance has gone ahead for years without any special access arrangement. 

Zippo's Circus was being set up in the Great Field near to Horse Close Wood, taking over the car park there for the duration, once more showing no need for a public car park there if it can be sacrificed to the alter of an attraction. The vehicles on the damp grassland were causing damage, as usual. One hopes that re-instatement will be more prompt this time. In keeping with Merton's much vaunted energy policies, I noted a big bank of diesel generators running day and night.