Posted by & filed under Biological Cleaning, Dams, Earth Banks, Gabions, Irrigation, Land, Material, Potable Water, Regional Water Cycle, Soil Erosion & Contamination, Soil Rehabilitation, Storm Water, Swales, Terraces, Water Conservation, Water Contaminaton & Loss, Water Harvesting.

This excellent little 20-minute video does a great job of covering the basics of watershed management and landscape rehydration. You won’t hear the words ‘permaculture’ or ‘swales’ once, but it’s clear that both are in use here, to great effect. If we can get these simple but profound concepts driven into social consciousness, and applied broadscale, we would see that investment in labour pay dividends, as many of our increasingly expensive natural disasters and resource limitations would simply disappear, as we reinstate nature’s own moderating capabilities.

Our environment is progressively getting degraded because of overexploitation of natural resources. In a degraded landscape with little or no tree cover, and subsequently little soil cover, rainwater is not able to percolate into the ground. We lose rich top soil with this running water, which flows away into the streams. It is a vicious cycle — no top soil, no vegetation, increased run off of water and further erosion of top soil. Holistic watershed development is the answer to break this vicious cycle.

This video film explains the importance of the ‘Ridge to Valley’ approach. It explains the various area treatments in non-arable waste land, cultivable land and also speaks about drainage line treatments. This video film highlights the technical and social components and the reasons why watershed work should start from the ridge and progress downwards towards the valley. — YouTube

Further Reading/Watching:

7 Responses to “Ridge to Valley – a Holistic Watershed Perspective”

  1. Greg Bell

    Interesting that their “Water Absorption Trenches” are not continuous (08:02 and 08:11)… also that they say structures will fill with silt and become useless (but not the the WATs?).

    Reply
  2. Jonathan Teller-Elsberg

    Greg, I think the point of the issue with structures filling in with silt is this: if you try to control water ONLY in the waterways, you have done nothing to slow soil erosion off the slopes. The result is rapid silting up of the water control structures, eventually rendering them more-or-less useless. However, with WATs and other structures designed into the slopes, you are slowing the water down precisely in the place where the erosion has been occurring. A WAT/etc. thus provides the mutualistic benefit of slowing water for sake of groundwater recharge and slowing water for sake of erosion control.

    Over time a WAT will likely fill — either with silt or fallen leaves of the vegetation planted alongside the trench. In this case, they either will need to be dug back out or such digging will be unnecessary because the water absorption capacity of this fill material is high enough (e.g. with high organic matter content from degraded vegetation fill) that it still functions to slow and capture rainfall runoff in the shape of a terrace rather than in the shape of a trench.

    As for the discontinuities in the WATs, I’m not sure why those are there. My first guess is simply as walkways for people crossing the trenches. The trenches are wide enough that some people would have trouble stepping entirely across.

    Reply
  3. Dan French

    Great article Craig, one thing I often notice lacking with discussion about modification of stream flow, such as installing check dams, is the impacts this has upon migrational pathways for fish. Being an essential part of aquatic ecosystems and nutrient recycling, not to mention protein as a food source, this issue also needs attention by permaculturists looking to restore natural ecosystem function. These issues can sometimes be mitigated by the installation of a fish ladder. This engineering addition however also requires some careful consideration as requirements differ according to species, life stage and life strategy. I have included 2 references which provide an explanation of function and some of the considerations of design.
    http://www.dpi.nsw.gov.au/fisheries/habitat/rehabilitating/fishways
    http://www.fao.org/docrep/010/y4454e/y4454e00.htm

    Reply
  4. david spicer

    nice one craig

    what ever works when hydrating landscape from source to sink or ridge to valley, start at the top and work down,think water think gentle all applyied in this doco

    some better spillways would be good, but well done I say

    Reply
  5. Ben

    Great to see. These people are self empowered and self motivated to make the necessary changes for a beautiful and healthy landscape.

    Reply

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