Throughout history, new technologies have extended humanity’s abilities beyond the physical reach of our five senses and have led to dramatic changes in our worldview. For example, the telescope permitted scientists to observe outer space and enabled Galileo to change forever the image that the established scientific community had of Earth’s place in the solar system. The microscope led explorers like Pasteur and Koch to eradicate traditional beliefs about the origin of diseases. This century’s “electronics revolution” and the advent of the “space age” have opened another historic window of opportunity.

For the past thirty years, Earth observation from satellites has enabled scientists to examine broad views of large regions of the planet’s surface, providing insights into the dynamics of complex regional natural systems from plate tectonics and oceanic currents to the hydrologic cycle. At the same time, advances in geological theory, geophysical instruments, and interpretive methods have contributed unprecedented information about the genesis and structural attributes of the Earth’s crust.

Additionally, the perfecting of computer-based data management and geographic information systems has allowed hydrogeologists working in the field to combine and analyze many different types of data quickly and accurately. The integration and synchronized application by economic geology of these new intellectual and physical tools has led to breakthrough discoveries of oil, gas, and minerals that far exceed the dire predictions of most economists in the 1970s.

Paradoxically, while modern science and technology have assured the world of plentiful future energy, the most life-sustaining economic mineral of them all – fresh groundwater resources – has been almost entirely overlooked by mainstream government and business entities and has remained the purview of a few determined researchers.

Despite the low public profile of such efforts, a 30-year period of focused groundwater research, development and testing has raised the bar significantly, as evidenced by groundwater discoveries in Africa, North America, and the Caribbean Basin that increases estimates of local, sustainable groundwater ten-fold or more. 

These discoveries have redefined basic hydrological concepts and introduced relatively new jargon into the lexicon of hydrology, one being the “Megawatershed.” In a megawatershed, a much larger area is considered to be contributing additional water to groundwater extraction wells in any given area, generally as a result of fractures beginning far away but leading to a particular well bore.

The megawatershed paradigm will soon replace the traditional, synthetic watershed model of topographically constrained surface catchments with an accurate depiction of regional, tectonically controlled fractured bedrock basins, and discoveries of megawatersheds in freshwater-short regions. Discoveries from Somalia to Trinidad and Tobago have led to the development of tens of millions of gallons per day of sustainable, potable water where no other groundwater existed, according to prior studies using conventional methods.

The traditional “watershed” model is a synthetic drainage basin reflecting convenience rather than reality. Conventional hydrological theory assumes drainage and water balance are controlled entirely by local topography, which is depicted on watershed maps derived from analysis of available, often dated topographic maps and aerial photographs.

Traditional watershed maps largely ignore the hydrologic implications of underlying geologic structures such as rainfall capture and drainage areas that may far surpass the impact of local topography. Indeed, most deep groundwater resources are traditionally considered “fossil” and are excluded as active parts of the water balance because they are deemed to be hydraulically isolated and non-interactive with surface watershed catchments.

Many government officials, water scientists, and engineers are now aware of the need to employ modern concepts and unconventional technologies in pursuit of their undiscovered, subterranean water resources.

Most critical are the artificial constraints placed on the areal extent of watersheds and the exclusion of underlying, hydraulically conductive fracture systems that often persist across and beneath topographic bounds.

The megawatershed paradigm contains within it the water balance equation of traditional watersheds but greatly extends the catchment, transmission, and storage boundaries by recognizing the overriding influence of tectonically induced, large-scale fracture permeability in defining the hydraulics and hydrology of a basin. Additionally, a groundwater exploration program specifically designed to investigate megawatersheds provides a much more comprehensive data acquisition program with a rigorous validation process that largely eliminates the errors inherent in traditional hydrological studies of groundwater environments.

Improved understanding of groundwater environments gained from the megawatershed model recognizes substantial interaction of rainfall, surface water, shallow aquifers, and fractured bedrock aquifers representing a hydraulic continuum, with surface and subsurface water drainage strongly controlled by fault and fracture zones in the bedrock.

This is all great news for a thirsty world rapidly approaching 8 billion people!

Robert Bisson, the developer of the Megawatershed concept, will be our guest on The Other Side of the Story this weekend at America Out Loud Talk Radio at both 11 am and 8 pm on Saturday, September 17, and Sunday, September 18.