Traditional Water Harvesting Infrastructure in India

 

Water Harvesting in India - Rotary Internationsl

On the rocky hills of India's west coast villagers struggle with a growing population and growing water shortages.

 

America's Water: The World's Water

We live in a bountiful land that extends from sea to shining sea. We are home to the world's largest freshwater reserve, the Great Lakes.

The waterfalls and serene lakes from Yellowstone to Niagara to Yosemite to Havasu inspire us as to the wonders of nature. Our inland waterways from the mighty Mississippi to the sinuous Colorado have been the backbone of a nation's exploration, freight and development. Our unseen groundwater reserves, much larger in volume than the fresh water in rivers and lakes, have nurtured our cities and our fields, providing the resource that makes us the most productive agricultural nation on the planet. We live an enviable lifestyle. For most of us, inexpensive, safe drinking water flows from the tap and we use it luxuriously for drinking, bathing, maintaining beautiful yards, golf courses, swimming pools and water theme parks. This access to nature's largess is in clear contrast to the global water crisis that many talk about -- the billion people in diverse countries who lack access to safe drinking water. But so is our wealth.

Today, America's water is at a crossroads. The last decade has been marked by a series of widespread droughts in the West, Southwest, and Southeast that stressed water systems and led to interstate conflict. The large aquifers in the Midwest, in Central California and in Florida are depleting. Recent floods have also stressed our infrastructure, response and recovery systems. These events bring into question our resilience to climate variability. Surely, it is better than in the 12th and the 13th century when the industrious and proud Anasazi vanished following major droughts. But, today we have a larger population with much higher consumption rates, and much of the world depends on our agricultural production that is fueled in part by vanishing aquifers. We have an ever-growing hunger for energy. The availability of water constrains where we can put thermal power plants and the amount of water that can be used for unearthing energy (e.g., hydrofracking), leaving renewable energy development at the forefront.

Regulatory efforts at controlling water pollution from industry and other "point" sources have been by and large successful and have contributed to a dramatic improvement in river and groundwater quality in many places. But, non-point source pollution from farms and cities is largely unabated. Nearly 2.5 million people in Central California are affected by high nitrate concentrations in the groundwater they drink. Nearly 2/3rd of the people who responded to a Value of Water Survey indicated that they had to boil their water at least once in the last year due to a disruption in supply.

Over the last decade, water rates have risen at a rate much faster than inflation, partly because they were too low given past government subsidies, and in part to cover capital expenses associated with renewal or expansion of water and wastewater infrastructure. In many places, the rate increases have stimulated lower consumption. This translated into revenues lower than those before the rate increase, leading to many utilities unable to cover operating costs. The ASCE estimates that nearly $1.5 trillion needs to be invested in the next 20 years to renew aging water and wastewater infrastructure, dams and levees. Federal investment in water declined significantly since the 1980s, and the infrastructure has aged since to the point that major renewal may be needed. The financial burden for providing water services has shifted increasingly to local communities. The ability of these communities to raise funds for capital improvements is under question.

The challenges related to climate-induced risks, to energy and agricultural productivity, to pollution and the quality of water supplied, and to the financing and governance of water systems that we face are universal. Every nation, every community in the world, is increasingly facing these challenges. The challenge is extreme in places like India where the highly variable climate, the pressures of the population and the stasis of the bureaucracy combine to create a living disaster. The same is true in places like Haiti where all aspects of development need attention. Solutions for the world are likely to be easier if places where there is technical and intellectual capacity, which if not constrained by an immediate challenge can innovate systems and principles that lead us to appropriate, sustainable solutions in all our environments so that the world is a healthy place for 9 billion people living in harmony with nature. It is a time for leadership in and from America.

Over time, much of the world adapted the U.S. paradigms for scientific and economic water management and development that were formalized and articulated through public and educational institutions over the last century. Principles of public benefit cost analysis for water systems were articulated. The application of these principles was stimulated by Federal government investment in water research, water storage, distribution and treatment infrastructure projects, and in the monitoring and regulation of water quantity and quality. The idea of the human right to water was made explicit by the U.S. government only recently, but was effectively practiced through its policies and investments. The legacy of these investments includes the vast civil engineering projects that brought us dams, canals, levees, sewers, drinking water and waste water treatment, the Clean Water Act that led to the assurance of water quality, and the Superfund program aimed at hazardous waste sites that severely contaminated water sources. Similar programs have emerged worldwide. More

 

The Coming Global Water Crisis

What happens when demand for this essential resource starts exceeding supply in many parts of the world?

The recent UN alert that drought in the Sahel threatens 15 million lives is a harbinger of things to come.

In the next twenty years, global demand for fresh water will vastly outstrip reliable supply in many parts of the world. Thanks to population growth and agricultural intensification, humanity is drawing more heavily than ever on shared river basins and underground aquifers. Meanwhile, global warming is projected to exacerbate shortages in already water-stressed regions, even as it accelerates the rapid melting of glaciers and snow cover upon which a billion people depend for their ultimate source of water.

This sobering message emerges from the first U.S. Intelligence Community Assessment of Global Water Security. The document predicts that by 2030 humanity's "annual global water requirements" will exceed "current sustainable water supplies" by forty percent. Absent major policy interventions, water insecurity will generate widespread social and political instability and could even contribute to state failure in regions important to U.S. national security. (Look here for a webcast from the Woodrow Wilson Center of experts and U.S. government officials discussing the findings.)

The simultaneous ubiquity and scarcity of water is one of Earth's little ironies. Globally, 97.5 percent of H2O is contained in world's oceans. Of the planet's "fresh" water (the residual 2.5%), more than two-thirds is encased in ice packs and glaciers, particularly in Antarctica and Greenland, another thirty percent in groundwater, and almost one percent in high latitude permafrost. That leaves us with about 0.4 percent of global fresh water to account for: about two-thirds of that is contained in freshwater lakes, with the rest distributed among soil moisture (12 percent), the atmosphere (9.5 percent), wetlands (8.5 percent), rivers (1.5 percent) and vegetation (1 percent).

The need for reliable sources of fresh water is as old as our species, of course. What is new today is the combustible combination of surging global demand for increasingly scarce fresh water in certain volatile regions of poor governance. Several factors are driving this trend.

• Demographic pressure: By 2025, the world's population will swell from seven to nearly eight billion. The vast majority of this increase will occur in the developing world, particularly Africa. In rapidly expanding urban centers, demand for fresh water will rise for personal consumption, sanitation, industry, and hydroelectric use.
• Declining Fresh H2O supplies: According to Global Water Security, "one third of the world's population will live near water basins where the water deficit will be larger than 50 percent by 2030." Many regions that are already experiencing water stress will become "extremely more stressed" or even "exceptionally more stressed." In some areas, rapid depletion of underground aquifers will be the culprit. In others it will be reductions in meltwater as glaciers recede. In the Andes, hundreds of glaciers will simply disappear in coming decades, eliminating dry season water supplies. Similar, though more gradual, dynamics will be at play in the Himalayas, sometimes referred to as the world's "third pole".
• Changing dietary preferences: Meanwhile, the global middle class will surge from 1.8 to 4.9 billion by 2030. Wealthier populations will consume more meat, requiring a shift to more energy and water-intensive agriculture focusing on the raising of livestock and feed grain. Already today, some 93 percent of fresh water consumed is devoted to agriculture (from a combination of riverine, lake, and groundwater sources). Without massive behavioral changes, changing land use and food consumption patterns will place even greater pressures on fresh water resources.
• Poor Water Management: Adapting to a new era of water scarcity will require enormous investments in integrated water management, particularly in the developing world. This would include improving agricultural efficiency through new irrigation systems and drought-resistant crops; renovating infrastructure to reduce urban "water leakage" (which averages 30-50 percent in many cities); clarifying rights to the use of subterranean, riverine, and lacustrine water resources; and introducing pricing mechanisms that reflect the true economic value of water--admittedly a politically volatile step in societies where free (or cheap) access to water is viewed as an inherent, longstanding right.

Significantly, the intelligence community does not predict that increased competition for water resources will, by itself, be a source of violent conflict--a finding borne out by a rich body of research. And yet the same document warns that water stress may well "contribute to the risk of instability and state failure," particularly "when combined with poverty, social tensions, environmental degradation, ineffectual leadership, and weak political institutions." The accompanying map makes clear that many of the countries likely to be hardest hit are fragile and/or authoritarian states located within the broad arc of instability encompassing North Africa, the Horn, the Arabian Peninsula, and southwest, central, and south Asia. In other words, states least able to cope.

Regional tensions over shared river basins will also rise. States will use diplomatic and other leverage to preserve their water interests, and "upstream" states will be tempted to use water as a diplomatic weapon, including by threatening to impede flow. Nonstate actors, notably terrorists and other extremists, may also seek to sabotage dams and other infrastructure.

Regional stability and peace, therefore, increasingly depend on effective management of the world's 263 shared international water basins. "Today, water basin agreements often do not exist or are inadequate." Analyzing the current capacity to manage seven major water basins, Global Water Security assesses mechanisms to govern the Brahmaputra and Amu Darya to be "inadequate," and those governing the Tigris-Euphrates, the Nile, and the Mekong as "limited." (The Indus and the Jordan rivers earn a higher, "moderate" score.) More

'Sand dams' bank water for dry season in semi-arid Kenya

MAKUENI, Kenya (AlertNet) – Barely a month after heavy rains pounded Kenya, many seasonal rivers in the country’s semi-arid east are already drying up, and residents are preparing for the months-long dry season.

But some, like Paul Masila and other members of the Woni Wa Mbee self-help group, are not worried about the looming dry spell. Instead, they are preparing to plant crops or are harvesting fields they planted before the rains.

The group – the name means “progressive vision” in Kamba, the local langage – have revolutionised the region’s fortunes by finding a way to store millions of litres of water under the bed of the Kaiti River, providing the once-parched community with water for domestic use and irrigation throughout the year.

“Drought will never again be a problem, particularly for future generations,” said Titus Mwendo, a 31-year-old farmer in Miambwani, in the Eastern region’s Makueni County.

The Kaiti, like other seasonal rivers in the region, fills with water only during the rainy season, which usually arrives in December.

“The rest of the year is characterised by scorching sun, dry rivers, dusty roads – only those who are fit can survive,” said Masila, a member of Woni Wa Mbee.

But Woni Wa Mbee and other self-help groups in the area, aided by local non-governmental organisations, have found a way to trap and store the Kaiti’s water in its own sandy riverbed, keeping water available for months after the river has disappeared.

“The water reservoirs are called sand dams,” said Kevin Muneene, chief executive officer of the Utooni Development Organisation, one of the supporting NGOs. Over the past two years, the organisation has helped 80 self-help groups construct 1,528 sand dams in arid and semi-arid areas of Kenya’s Rift Valley and Eastern region.

CONSTRUCTION DETAILS

To make a dam, he said, a high concrete barrier is constructed across a seasonal river. When it rains, the water carries sand downstream, depositing it up to the level of the barrier. When the rains finish, water remains trapped in the piled-up sand for up to a kilometre upstream of the dam, depending on the dam’s height.

“A well-constructed sand dam has 60 percent of its volume as sand, while the remaining 40 percent is always water,” said Muneene, an expert in sand dam construction.

In terms of volume, it is estimated that an average sand dam in a relatively wide stream such as the Kaiti River can hold up to 5,000 cubic metres of water, equivalent to 5 million litres. To boost the volume of water stored, several sand dams can be built along one river.

Those numbers suggest that the 1,528 sand dams already built as part of the project will be able to store up to 7.7 billion litres of water, which can be used to irrigate thousands of hectares of land and supply thousands of households for months after the rains stop.

To use the water, community members scoop out sand from the river bed to expose it. It can then be pumped out for irrigation or other uses.

Over 3,000 households are now using water from the dams to grow vegetables, tomatoes, drought-resistant legumes, fruit trees such as grafted mangoes and oranges, and other crops.

“For the first time, we have had water throughout two years. This is not a common phenomenon in this area,” said Florence Munyoki, the treasurer of Woni Wa Mbee and a smallholder farmer in Utaati village. More

The top of the dam is I believe, supposed to be level or just below the the normal river bed. Pictures and drawings that I have seen in other areas in Africa are built in the way I describe. Built in this manner they will not act in a way that may obstruct the run of the river. Editor