Waffle cities: landscape planning, urban design and architecture for flood-prone regions and global warming

Long term landscape planning for the type of floods which have afflicted Australia could involve designing the landscape in the manner of a regional waffle. Much of the problem seems to have been caused by flows of water on an almost continental scale. The principles, as for Sustainable Urban Drainage Schemes, (SUDS) should be to detain, infiltrate and evapo-transpire flood waters. This process would be assisted by raising embankments where possible: field boundaries, roads, garden boundaries etc should all become dykes. In some cases the dykes would protect against floods but the main objective would be to stop the flood water cascading from zone to zone. Also, the dykes would serve as wild-life corridors and sanctuaries. My guess is that waffle-type measures would be cheaper and more effective than building large dams. The next stage would be to move from flood landscape planning to flood landscape architecture, by finding other uses for the dykes and by making them beautiful as well as useful. Individual properties would gain some similarities to motte-and-bailey Norman castles. Another advantage of waffle landscape planning is that when the rains come there will be more time for water to infiltrate into the ground and re-charge aquifers – in preparation for the next long period of drought. Does anyone know if waffle landscape planning has been considered, and if the engineering calculations have been done?

Image courtesy mhaithaca

15 thoughts on “Waffle cities: landscape planning, urban design and architecture for flood-prone regions and global warming

  1. Jeremy McKenna

    Your waffle looks much like an aerial photograph of the Netherlands. Grassy dykes divide fields throughout Zealand and are maintained by grazing sheep. They channel water into ditches and canals where it is pumped back out to sea by a sophisticated system of windmills, locks and weirs. The Dutch, in any case, are the world’s recognised experts when it comes to water management and were the first engineers called in in the wake of Katrina in New Orleans.

  2. Lawrence

    The planting of dykes with anything but grass is forbidden in Hamburg and they are thus of very limited value as wildlife corridors. Fast-moving flood water can pluck even large trees out by their roots, so damaging the structures. I have never had explained to me why planting on the “dry” side of the dyke is also forbidden but I do know that the authorities allow no exceptions to the rule. Where trees are discovered they are mercilessly felled. Sheep on the other hand are encouraged as their constant grazing improves the reinforcing root mat of the grass sward. “Deichlamm” (literally “dyke lamb”) from Hamburg’s hinterland is very highly prized, costing roughly twice as much as imported lamb from New Zealand.

  3. Tom Turner Post author

    I can see their point with regard to tree planting on river embankments but assume the same principle would not apply to planting on embankments which surround fields, homes and other properties (ie where the embankments are not exposed to fast flowing water),

  4. Tom Turner Post author

    Jeremy: I agree that Holland points the way. But it is only a tiny patch of land, compared to the area of Australia affected by floods, and the polders, by definition, are all low-lying. In Australia it would be necessary to detain the water upstream so that downstream flooding is delayed and diminished.
    Christine: I think that even central Brisbane would benefit from waffle planning: levees would keep floodwater out of the city (except when it was above the planned flood defense level) and they could also protect higher land within the city. But the main thing, as in my response to Jeremy, would be to delay the water upstream and lower the flood peak in Brisbane.

  5. Christine

    Much of the flooding Brisbane experienced was due to water releases from Wivenhoe Dam [ http://www.youtube.com/watch?v=7cOgP8lgCL4 ]
    which at the time of the flood peak was at 190 + of capacity [ http://www.couriermail.com.au/ipad/wivenhoe-water-releases-wound-back/story-fn6ck45n-1225986185721 ] after falling to critical levels of 15 percent capacity during the recent drought. [ http://au.news.yahoo.com/latest/a/-/latest/8691144/q-a-dam-expert-analyses-wivenhoe/ ].

    The difficult issue for dam managers is that the majority of water in the Wivenhoe catchment comes from extreme weather events ie. cyclonic and monsoonal weather events and above average rainfall during the ‘wet’ season.

    This water is potentially the supply for the city (with a rapidly growing population) for up to the next ten years. The catchment, if I understand the situation correctly, is also managed on the basis of statistical averages, whereas flood events (like the mythical family with 2.2 children) ignore averages.

    The localised flooding where I live came not directly from the river but from the backed up stormwater system (city infrastructure) as the river rose. Mapping to identify the different sources of flooding in each area would be necessary to design appropriate defence mechanisms.

  6. Tom Turner Post author

    I see that making Brisbane into a waffle would not protect it from floods – but what if the entire catchment of the river were to be planned as a waffle? Wouldn’t that deter the Great Flood Lake from its course of meandering havoc through eastern Austalia? The general principle for water management is to detain and infiltrate the water as close to where it falls as possible. If you let the water accumulate it causes trouble.

  7. Christine

    Yes it seems there was a relationship between the January 1974 flood in Brisbane
    [ http://en.wikipedia.org/wiki/1974_Brisbane_flood ] and a spectacular flood in the inland lakes
    in February 1974 with “a peak 15 890 GL”. The lakes are also considered to be sites of net sedimentation deposition from flood waters. The paper below looks at these impacts on fish populations in the lakes.

    From a cursory reading of the paper on ‘Hydrological persistence and Dryland River Ecology’
    [ http://onlinelibrary.wiley.com/doi/10.1002/1099-1646(200009/10)16:5%3C385::AID-RRR592%3E3.0.CO;2-W/pdf ] the retention of floodwaters increases the extent rather than the volume of subsequent events: (p393)

    “Thus, while the volume of the 1991 flood was 36% of that in 1989, its maximal extent (22 April 1991) was 64% of that in 1989 (7 July 1989).”

    It is fascinating to understand that the issue of flooding we are evaluating for the city of Brisbane is system wide with almost nation wide implications. Undoubtedly it also has impacts for RAMSAR wetland management, and thus has an international dimension.
    [ http://www.ramsar.org/cda/en/ramsar-home/main/ramsar/1_4000_0__ ]

    This said, I don’t think the ecological data should deter the generation of ideas, as there are many flood situations, so the more ideas the better.

  8. Tom Turner Post author

    The problem with having one big dam is that if it fails to hold back the water then you have one big flood. If however you have lots of small dams (ie compartments in the waffle) then there are more likely to be lots of small floods then one big flood.
    There was a fashion for late-medieval moated manor houses in many parts of north Europe and I think it would be worth encouraging designers to consider what urban areas might look like if planned on this basis:
    – the water courses would have visual, ecological and recreational roles
    – the embankments would be green transport routes, visual barriers and acoustic barriers
    – the greenspace on the sides of the embankments could be used for urban agriculture (including the Deichlamm Lawrence mentions, above)
    – embankments could supply ground-source heat pumps and a thermal contribution to climate control within buildings (ie by insulation).
    – bees would flourish on the embankments so that we could dispense with refined sugar (which causes more ill-health than hard drugs) and have a good supply of honey for our waffles
    So lets design Waffle Cities!

  9. Christine

    Yes waffle inspired landscapes, waffle inspired architecture [ http://www.en-derin.com/artworks/steampunk-futuristic-cities-homes-and-factories ] and waffle inspired cities all have something to contribute to how we might rethink how to manage floods.

    One of my favourite ‘waffle’ buildings and landscapes is the Bangkok Embassy by Ken Woolley.
    [ http://www.austembassy.or.th/bkok/AboutUs_building.html ] There are very few pictures available on the internet and while these do the design justice the web gives a description of the essence of the design.

  10. Tom Turner Post author

    The space around Ken Woolley’s Bangkok Embassy can certainly be regarded as an example of how one of the depressions would be treated in a future Waffle City.

  11. LIZ

    Another Dutch master Mondrian made geometry and colour interlinked – I see waffles associated
    with his 2D designs, and to give more perspective to the drainage how about Jelly moulds in grids to represent the red yellow and white

  12. Pingback: Waffle levee flood planning for the Mississippi | Garden Design And Landscape Architecture Blog – Gardenvisit.com

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