Because the East-African country of Kenya straddles the equator, it goes through a short and long rainy season broken by a short and long dry season. The seasonal riverbeds created by these seasons provide water for a few months out of the year, but the water is full of sand and mud from upstream and quickly empties or dries.
Sand dams make use of the rainy seasons and the sandy water by creating artificial aquifers in the seasonal riverbeds. The sand washed down the river accumulates over two or three rainy seasons behind the concrete dam and actually retains up to forty percent of its’ volume in water (Brahic). This shallow aquifer can provide water to a community for many months after the rainy season has ended.
Excellent Development is a London based charity founded by Simon Maddrell and Joshua Mukusia which focuses on the development of Kenyan water sources. Practical Action is also a UK based charity which focuses on Kenyan water sources with a foundation built on studies done by Sahelian Solutions Foundation (SASOL) and Maji na Ufanisi. Both organizations use the construction of sand dams to improve the reliability of water to communities in the ASAL areas of Kenya, and consider the project’s life-line the community that the sand dam will benefit.
SASOL states, “The local community has to take the initiative, indicate the stretch of river where water storage would be most useful, and agree to provide the labor needed” (SASOL 36). Excellent Development corroborates claiming that the success of a sand dam depends, not only on correct design, but also on community ownership (Excellent
Seasonal riverbeds provide the best location for the dam, whose foundation must be based on an impermeable sub-layer of bedrock found by digging a trench across the riverbed (SASOL 37). The dam itself is then constructed of materials mostly found in the local community; timber, sand and stones, and water with the exception of Portland cement and binding wire (Practical).
Portland cement can be a very costly material for the communities, costing around Ksh 1000 per 50 kg bag in Nairobi and constituting around 85-90 percent of the total construction of the sand dam. This has led to research into alternative materials for the construction of sand dams in the lands of East Africa.
Posted by Willems Leveille at 4:28 PM 2 comments:
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Water is the earth's source of life. Without it, we basically cannot survive. There is a looming crisis in the world today regarding water. It may not seem so, but many things are tied to water. From the production of electricity, to making clothes, for producing food, to producing steel, to keeping us cool and quenching our thirst. It takes 62,000 gallons of water to produce one ton of steel and 1360 gallons for one ton of cement. (Amount water needed to produce Steel and Cement.) About 26 gallons is needed to produce 1 kilowatt hour of electricty. It takes about 39,090 gallons to produce a new car including it's tires. It takes four gallons to produce one gallon of milk, 1800 gallons to grow enough cotton to produce one pair of jeans and 5.4 gallons to grow enough wood for one lumber board. (Water Facts)
This was very shocking to me to find out a few years ago that water was used for all these things because It doesn't seem that water is used for more than the daily chores we do at home.
So as the earth keeps warming up and the population keeps increasing, the demand for water will only skyrocket. The effects don't really seem so large here in the United States, but in various areas across the world there are water fueled riots because of shortages. The Arab Spring that started in 2011, many say, was partly the result of rising food prices. (Rising Food Prices - Arab Spring) Sana'a, Yemen is risking the possibility of becoming the world's first capital to run out of viable water supply as Yemen's streams and natural aquifers run dry. (Yemen Water Crisis)
For us in the United States, signs were given that when it comes to water shortages, we are not safe from any danger as well. The drought that occurred in the Midwest United States showed use just that. The drought has caused food prices to soar up.
Can you see the picture?... Rising temperatures... Rising Populations... Decreasing water supply... BIG PROBLEM... Water wars could actually become the new norm.
I remember watching a documentary called "Blue Gold: World Water Wars" describing how corporations are jumping on this opportunity of water shortages to... MAKE... A... PROFIT... They are trying to privatize the water supplies. Basically putting a fence around any major lakes or freshwater habitats and calling their own. The documentary says that many water companies have sprung up the past few years as a result. (Video Below)
The need to for sustainable practices in the use of water is not really an option at this point. With unemployment still high and some countries still in a recession around the world, the threat of higher food prices and low water supplies can trigger upheaval in the most stabilized of countries. This poses a huge challenge to us as people to further overcome these obstacles with corporate greed adding to this dilemma. In fact there are many across the Middle East and Northern Africa already experiencing this hellish condition. It is stated that between 50,000-100,000 people have died in the 2011 Horn of Africa crisis affecting countries like Ethiopia, Somalia and Kenya where more than half were children under the age of five. (Horn of Africa Crisis)
Thats the reality of many people living in the world today.
Imagine your world... Without Water.
Posted by Willems Leveille at 6:30 PM 4 comments:
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“The ultimate test of a moral society is the kind of world that it leaves to its children.”
Green building, Green energy or just Green ANYTHING... Is more than an economical choice or path that should be taken. It should be thoroughly invested in and put in real focus for the world today, but ultimately the world tomorrow. The effects of our ENORMOUS dependence on fossil fuels can clearly be seen in today's world with the increasing global temperatures and depleting ozone layer. Fossil fuels will not last forever, as we all know, so it is imperative for us as a people to make investments in renewable energy now for well being of younger generations, my generation and the earth as a whole.
As a young child, I've always loved building things and decided since third grade that I wanted to do just that when I go to study in college. So, I got my undergraduate degree in Civil and Environmental Engineering at the University of Massachusetts at Dartmouth. During my undergraduate career, I did many research projects with various professors, but the research project that I participated in in Kenya with Dr. Esther Obonyo was the most rewarding.
That project consisted of researching alternative materials to concrete for the use of sand dams in the Arid and Semi-Arid Lands of East Africa. A sand dam is basically a concrete wall built across a river bed, during the dry season of East Africa. So during the rainy season, the water will accumulate behind the wall and eventually sand as well. So it creates a reservoir, where the sand acts as a filter and protects it from parasites. As a result, the local villagers have water year round and the water table gets replenished causing the growth of plants within the area. I will have a separate blog on the project in the coming weeks. It was this project that first introduced me to Sustainable Construction and Development. It ended up being a very eye opening experience as to what can be done through engineering to help the lives of anyone.
After this, I wanted to further my studies and obtain a Master's degree in Construction Management focusing on Sustainability. So, this is why I am here now interested in and focusing on sustainability. Being Pro-Green should, in my opinion, be everyone's mindset because it just is the right thing to do, but for those who don't really care about that then it does produce a economical benefit as well. Being Pro-Green, I believe, has the potential for ingenious innovation in the science fields. The evidence can be seen in the challenges that can be posed when a group of people want achieve a certain LEED rating because it's a new way of looking at the built environment. Or the difficulty of finding a viable replacement to fossil fuels because they have been the standard for so many years that anything that does not produce the same or more power than them is almost not feasible. These challenges only cause us to break new ground and find a solution.
So for me, being Pro-Green is just a duty we all have for our generation and the generations to come. So we leave them a world that is not on the verge or the brink of being... UN-INHABITABLE...