Water Journal : Water Journal May 2015
WATER MAY 2015 12 Postcard POSTCARD FROM THE MISSISSIPPI From Steve Posselt, Kayak4earth Steve Posselt is paddling to Paris. Kayak enthusiast Steve’s passion is water – but he believes the earth as a whole is more important and the Paris Climate Summit in November is critical to what sort of world our grandchildren will inherit. ‘Connecting Climate Chaos’ is an account of his journey in his trusty wheeled kayak, highlighting extreme weather events: a Canberra fire storm, Sydney fires, Hurricane Katrina, Superstorm Sandy, UK floods and French drought. The US leg is up the Mississippi and across to New York, over to the UK, the English Channel and up the Seine to Paris. After completing the Australian leg in January my journey up the Mississippi so far has been up the river from New Orleans to Vicksburg, home of the US Army Corps of Engineers who control the river. And control it they do. The sheer magnitude of the levee system and river structures is mind-boggling. That said, the engineers are under no illusions about the limit of their control. Even with the mighty resources of the US, Mother Nature can still have her way. The first 280km was bad enough, with strong currents and very busy traffic, including huge sets of barges and ocean-going ships. All the time the river was rising steadily, fed mainly by the Ohio flooding – but at one point things turned infinitely worse. Thirty per cent of the river is diverted down the Atchafalaya River, which, as I passed through it was about 500GL/d. The flow against me then went to 1,500GL/d, which in anyone’s terms is a lot of water. The river is unlike anything we have in Australia. It is contained within levees, but there are large wilderness areas within those levees. The Corps of Engineers have to keep the river functional for the huge volume of traffic, and they now need to provide sediment to the delta area below New Orleans to stop it disappearing below the water. STEPPING BACK IN TIME All Australian Water Engineers know and respect the Corps of Engineers, but it was interesting to actually visit their water engineering headquarters and get a first-hand impression of the organisation after paddling there. Unlike Australian organisations, they seem to think that people qualified in the field are best to run the operation, so you will find an engineer, a hydrologist or someone used to doing calculations on the river in the top job. You will also find decisions being made by engineers. The engineering headquarters (although not the research arm) is like stepping back in time to an era before the nonsense started about engineers not being managers. Books and maps abound. Technical discussions with managers are easy. There is lots of space, large desks, organised clutter, and hallways, offices. At present a huge hydrological study is underway to determine whether their parameters are still valid and what the effects of climate change might be. My belief is that engineering has reached a zenith. Massive structures, massive control, engineering might, have all been well and good and have allowed the river to do what was wanted – but the approach seems to be softening. Environmental concerns are being addressed with care. The US, just like Australia, is turning into a drain, with everything speeding up. Farmers are even tiling parts of their fields to get rid of water more quickly. The river, therefore, has a lot more water flowing down it during floods than it had 200 years ago. In Australia, we saw in Toowoomba and Grantham in 2011 what drastically reduced times of concentration can do in an abnormal event. Interestingly, 2011 also was the biggest flood they have had on the Mississippi. Interestingly, with the river contained within levees, the term “flood” is not used until levels are extreme. At time of writing, the river in Vicksburg is up about 13m – and that is just at the start of flood level. Society has learned to live with river levels moving up and down more than 10m. Fishermen can be seen prowling the treetops in their tinnies on the weekends. Low, medium and high water levels are talked about, with the river being vastly different at all stages. of the US, Mother Nature can still have her way. of the US, Mother Nature can still have her way.
Water and CSG
Water Journal June 2015