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Water Conservation Solutions
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Nigeria: Climate Change and Water Management |
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Written by Administrator
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Thursday, 19 August 2010 15:31 |
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Farmers in West Africa need to develop strategies for harvesting and conserving rainfall. West Africa is a semi-arid landscape with unreliable rainfall that limits agricultural yield and population stability. Many proven methods for optimizing use of rainfall have not been adopted here where they are potentially beneficial to those in need, even with incentives such as food-for-work applied. Ultimately, an un-incentivised return to a traditional and largely abandoned conservation practice has yielded positive results.
A practice known as Tassa and as zai has become increasingly popular in Nigeria and its popularity has spawned a new enterprise for day laborers who have mastered the technique. Tassa is a method of conserving water in small hand-dug pits, some 20-30 cm in diameter, 15-20 cm deep and 0.4-1.0 m apart. When a Tassa pit is created, the removed earth is placed on the downstream side of the pit to form a small ridge and to retain more water before it escapes as runoff. The pit bottoms are then covered with manure to provide nutrients and improve water infiltration and retention. When it rains, the holes fill with water and farmers plant millet or sorghum in them. Tassa pits take 50-60 working days per hectare to construct and about ten working days per hectare to maintain, depending on the soil and rainfall. They need redigging every one-to-three years.
The use of Tassa in Nigeria was instrumental in bringing a total of 4,000 ha back into production over the course of a few years. In surveys, farmers cited several reasons for this rapid uptake: doubling of yields, rehabilitation of barren land, easy maintenance and easy weeding and thinning.
Tassa is a simple, inexpensive and easily implemented method for conserving rainwater and regenerating soild for agriculture in areas experiencing unreliable rainfall and climate change.
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Organic Soil Regeneration: Yield, Value, Profit |
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Organic Soil Regeneration Adds Value, Increases Profit, Improves Yield Where Market Prices are Falling.
CADISPA - Italy, the University of Strathclyde, and Nuovo Cilento are using Organic Soil Regeneration techniques to minimize agricultural inputs while producing higher value, higher quality Olive Oil. Organic Soil Regeneration practices retain moisture and improve agricultural water efficiency. Organic products offer a greater variety of marketing opportunities to growers, often relieving pressures from lower cost or higher volume producers in a market.
What agricultural products are best suited to develop a higher profit market for organic processes? |
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Lessons Learned: Flash Floods Kill 42. Water Systems Planning Needed. |
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Written by Administrator
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Tuesday, 10 August 2010 13:55 |
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In February, 2010 42 lives were lost when flash floods hit the tourist island of Madiera. Many parts of the island were left without power, communications and water.
The flooding followed an unprecedented downpour in which it rained 114 litres per square meter in just five hours in Funchal, which receives an average annual precipitation of 750 liters per square meter. While this volume of water was the cause of this disaster, much could have been done and can still be done to minimize the impact of significant weather events in places like Madiera.
In recent years, approximately 20 percent of the population has moved from the interior of the country to coastal areas, where 90 percent of economic activity is concentrated. As demand for coastal development increased, construction proceeded with insufficient planning for management of the natural runoff.
In this particular storm Madeira's three main rivers - the São João, Santa Luzia and João Gomes – overflowed their banks on their way to the sea. Along their path are numerous new developments leading down to the lowest-lying areas along the coast. The new development created a natural channel for the great force of this water to flow through when the river banks could not contain it.
Ricardo Ribeiro, president of the Portuguese association of civil protection experts (ASPROCIVIL), pointed to urban sprawl and uncontrolled construction in hilly areas at risk of flash floods and mudslides, the excessive paving over of land, which impedes drainage, and the poor inter-connection of waterways and flood channels.
With investment and infrastructure in place, what solutions exist that will help Madiera manage future flash floods cost-effectively?
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Last Updated on Tuesday, 10 August 2010 15:03 |
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Water Supply Management: Public or Private |
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The effectiveness of urban water management systems in delivering safe, reliable drinking water efficiently can greatly influence the economic viability of a region. Regardless of the role and responsibility of public and private stake-holders, the bottom line is that all urban water systems must be actively engaged in the following activities to provide sustainable and growth-capable services:
- financing for repair, replacement, growth and disaster preparedness.
- cultivating expertise in emerging technologies.
- Increasing efficiency in loss detection and systems repair.
- Improving detection and removal of hazardous materials.
Urban water systems require financing. Technologies to effectively filter, monitor, and deliver water through municipal water systems are largely developed in the private sector. Innovating technologies and techniques are being developed to continue to improve the quality and efficiency of the water we use.
Ultimately, the cost to consume water is driven by the relative availability of water supply and the effectiveness of the water supply management. Investment capable of meeting the demands of a changing demographic, incentivised to improve efficiency and quality is essential regardless of ownership of the profits.
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Shock Absorbers Eliminate Water Main Breaks |
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Written by Administrator
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Tuesday, 10 August 2010 14:51 |
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The deterioration of urban water supply infrastructure is a significant economic issue. As the integrity of an aging infrastructure decreases, the loss of finished water in the distribution system increases. The loss of integrity in the distribution system is evident by the increasing amounts of reported breaches in distribution systems. Improved water is a commodity, therefore loss of improved water in the distribution system results in direct loss of revenue.
The economic losses attributable to breaches in a water distribution system are compounded by the increased supply of treated water required to meet demand and the cost associated with repair and replacement during a breach. The American Water Works Association (AWWA) estimated in the Distribution System Inventory, Integrity and Water Quality publication that there are close to 237,600 water main breaks per year in the United States leading to approximately $2.8 billion lost in yearly revenue.
Ideally, no water would be lost, however this not achievable in the field. There is a point at which it costs more to locate and fix leaks than is economically justifiable. A balance must be maintained between water loss reduction and costs associated with water loss reducing measures. A leak for 10 days at 1,000 liters a day represents a loss of 10,000 liters. A smaller 10 liter/day leak for 1,000 days (around 2 years and 9 months) has a comparable loss. Prioritizing investment for the greatest return requires careful consideration of available options. A water provider can directly affect real water losses by controlling:
- Pressure management
- Speed and quality of repairs
- Active leakage control
- Selection of pipeline and related assets
Pressure Management:
Pressure management affects water loss rates. Also, the lack of pressure management has been shown to increase pipe failure rates. These are relatively intuitive ideas since more pressure means greater flow whether it is through the pipe or through a crack or hole in the side of the pipe. Higher pressures mean higher stresses on the pipe. Higher pressure also means higher pressure spikes during pressure surges. These higher values translate into increased failure rates. The management goal is to meet customer pressure expectations, fire flow requirements and adequate pressures to operate the system at as low a pressure as is reasonable.
Technologies that absorb pressure spikes, such as SAVCO’s AquaSphere, have effectively reduced the frequency of water main breaks. Pressure surge protectors may be added to a system during a water main break at minimal incremental cost. As breaks are repaired and additional surge suppressors are added to the system, the shock protection increases exponentially. Within a very short period of time, often within one year, the cost of adding pressure surge protectors to a water supply system can pay for itself in reduced water main break repairs alone.
Water systems with one or more of the following traits should strongly consider water surge protectors:
- Higher than average annual break frequency (more than 25 breaks/year/100 miles of pipe).
- Larger percentage of older, cast iron pipes throughout the system.
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Last Updated on Tuesday, 10 August 2010 16:11 |
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