23 May 2011

China has acknowledged that the Three Gorges Dam is becoming a huge headache, not least because of mounting pollution levels – gee, wasn’t that predictable?  Its a huge dam that is influencing local climate, creating small earthquakes (remember Kariba?) and “Both upstream and downstream, the flow of water is no longer fast enough to flush rubbish and toxic elements away. A report last year found that the Yangtze’s tributaries and lakes were contaminated with high levels of copper, zinc, lead and ammonium.”   The Three Gorges is such an immense dam that proactive management is almost impossible.  With smaller dams, however, ones that are more closely balanced to the upstream  catchment hydrology, can have reliable management plans in place before the dam is even filled. Its even easier for small developments (see here).

In Kansas, Clinton Lake – which is the same age (34 years) as the Western Cape’s Theewaterskloof Dam, is filling with sediments 70x quicker than predicted.  Guess who used the wrong model!  Cyanobacteria are also becoming a problem and TMDLs need to be revised – but I am not sure how if the sediment loading is so out of whack?

Grand Lake St Mary’s (Ohio) must be the most-reported site for algal problems and warnings have again been issued (see also here and here for comment on economic impacts).  The Hutt River (Wellington, New Zealand), the site of nine dog deaths from toxic algae, is also again cause for concern.

South Africa’s DWA has announced planned expenditure of ZAR14.2 billion to improve distribution infrastructure.  The same report also indicates how many people they are training, but makes no mention of water quality issues.  Environmental science students are apparently being funded but, as no universities in South Africa offer limnology, the training must be mainly focussed on hydrologists.

The recent report on the pollution threat to yet another South African dam (Lake Midmar) was surprising – not least the wishy-washy inaction from the DWA.  Surely they need to give effect to their constitutional mandate to protect our water resources?? Government apathy about the environment occurs everywhere (for example here) – which seems to be some excuse for it to be OK in South Africa too (did anyone see that nitwit from PetroSA on the TV on Sunday?).  See this more positive story for Lake Alice in Minnesota.

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