Water Water Water! The creator of constant change on earth. Water is almost always the most important aspect of any land or region. People live in all kinds of conditions on earth, but often the toughest places for survival are deserts. Water is vital for everything on earth living and non-living. So what do we know about water?
I think this is not news but it still amazes me that we can take water for granted and not think enough of recharging and taking care of this limited fresh water available to us. So approaching water from a permaculture point of view, we need to understand concepts that help in designing. The first and most important is watershed. Watershed Knowing the watershed for your land, area, region is relevant to both designing as well as conservation and maintenance of precious fresh water sources. So what is a watershed? According to the EPA " a watershed is the area of land where all the water that is under it or drains off of it goes into the same place" It is easier to understand it through a diagram. . In What this diagram brings out is the concept of watershed as well as the pattern of a watershed is referred to as dendritic; a branching pattern. It happens to be a very useful pattern for designing several systems such as transportation and even communities. Most water harvesting, recharging, and maintenance is feasible at the origin of the water sources such as springs, small streams, where rain falls etc. Keeping pollution out of these areas is possible and creates an healthy water eco-system. Big damns often ruin entire river eco-systems by disrupting the natural patterns of water flow. Another point that watersheds also bring out is that that water that you see on the surface may only be 15-20% of how much water there is underground. Building concrete canals and boundaries to rivers reduces infiltration tremendously and hampers groundwater recharge. All the concrete in the cities are the main reasons for falling ground water tables in those areas as very little infiltration takes place and most of the water runs off the land and into the sewage system. What poor use of something so vital. Rainfall In many regions rainfall may be the only or the major source of water. Being able to harvest this water, recharge ground water as much as possible during rains is the key to survival for many communities. Rainfall distribution through the year also determines what kind of an eco-system you have. Tropical landscapes that receive rainfall only for 3 -4 months in a year all in one season are brittle ecologies whereas temperate climates are blessed with evenly distributed rainfall throughout the year and have resilient ecologies. Resilient ecologies are able to bounce back very quickly from any kind of disturbance even due to the regular rainfall and therefore the ability for plants to survive. In tropical ecologies even though they receive a lot more rainfall in the 3 months than a temperate region does in an entire year, it is still a brittle ecology as the recovery from disturbance is very slow. Often the loss of top soil in a deforested area in the tropics occurs when it rains heavily. Rebuilding top soil is an extremely slow process taking hundreds of years if not more. While designing for a bio-region or a site, knowledge of the rainfall helps in deciding sustainable land use patterns as well as best water use, harvesting and conservation strategies. Principles of Water Harvesting The following are some steps to follow while planning water management for your site; 1. Begin with long and thoughtful observation and knowledge As mentioned earlier understanding the watershed, rainfall, geology, soil etc. of your area is key to creating a good design. It is good to be present to observe the land during rains as well as dry seasons to understand how it changes and how water flows on the land. 2. Start at the top of your watershed and work your way down It is easier and wise to make small changes at the top of your water system before investing in big steps. 3. Keep it small and simple Low cost, low maintenance, and long-term solutions are the best way forward for a permaculture design. It also increases accessibility for people with few resources. Here is an example of a low-cost system of a spring box used in India. 4. Slow it, sink it, spread it When water falls or flows, slowing it down, creating ways for it to collect and spread over more surface area leads to higher ground water recharge. A favourite example that permaculture often talks about is swales. Swales are trenches that can be human-made or natural that collect water temporarily and sink it into the ground. Creating series of connected swales can create a gently flowing and sinking water recharge system. Planting around swales is extremely effective and productive as can be seen from the diagram below. 5. Maximize vegetation and ground cover
As seen with planting around swales above, just having vegetation on the land with or without swales is more effective way of water harvesting than just barren soil. Vegetation naturally increases the water table by creating paths for water to infiltrate by making the soil porous. Plants always perform better than human effort can. 6. Continually reassess your system. Hopefully if you did a good job you just have to give it minimal attention. But the learning that comes with any project is immense and so assessing and observing beyond installation helps one grow as a designer and a student of nature. There are endless connections of soil, vegetation, and geology to water. But this is all that can be explored in this blog post. Feel free to continue exploring!
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