Is water a renewable resource or a nonrenewable resource? Why?
Water has been considered an exploitable and renewable resource from the beginning of civilization, but we have been creating limits to the water supply and reducing the natural renewal processes for even longer. We are now facing growing shortages of water for drinking, crop irrigation and sanitation, such that hundreds of millions of people are constrained in non-essential water uses like bathing and landscaping.
The obvious mechanism of water recycling is rain. Places which are habitable for hunter-gatherers are where monthly rain falls throughout the seasons are enough to drink, wash, and grow plants for food. Humans have been interfering with rain for 40,000 years, and this trend is now rapidly accelerating, with areas of continuing drought spreading around the world.
The primary regulation of rainfall is forests. There is a massive flow of water up into the atmosphere from evaporation from rivers, lakes, moist soil and plant metabolism, which supplies the moisture, BUT forests make rain by a combination of transpiration, which raises the humidity; reducing the temperature by both evaporation and converting solar energy to chemical energy instead of heat; and emitting microscopic organic particles which nucleate droplets to start rain storms.
This is the first way that humans disrupted the renewal of water. Humans annihilated half of all forests, 3 trillion trees, for firewood, cropland, grazing land, buildings and roads.
This has caused permanent droughts in many places where civilization started - North and South Africa, Middle East, Central Asia, and the US Southwest. It even caused permanent drought in Australia when humans arriving with stone tipped weapons and fire slashed and burned the great central swamp and extincted the man-eating marsupial cats and bear.
Healthy forests are aboriginal "old growth", never harvested. Forests are not renewing nor sustainable if any part of the forest is exported. Selling forest products extracts bio-essential elemental nutrients from the soil, which eventually deplete and make the land barren. In addition, studies of recently penetrated wilderness showed that bio-diversity drops 50% for ten miles on either side of a new road in only ten years, and this also reduces the viability of forests and their water recycling functions.
Many remaining forest are going dormant from drought. They are still standing, but not living and making rain, in a vicious circle. This dearth of tree metabolism also kills many animal and microbial species that kept the forest healthy.
Of our land uses, the only one which nucleates rain are the particulates in air pollution emitted by combustion fueled cities - but these rains are not healthy for drinking and irrigation, and wash down storm drains to poison the groundwater downstream. "Smokestacks" are no longer permitted to emit smoke particles in the US and Europe by law, but these Nixonian laws have been under attack since the Reagan administration and are not being enforced in the US under the current administration.
Water polluting particulates are still emitted in large quantities by motorized ships, motorized vehicles (including brake and tire wear particles), residential oil burning furnaces, wood burning stoves and fireplaces, forest fires exacerbated by drought, etc. in addition to coal fired energy in countries with no regulation or enforcement like industrial giant China - and these reach the US.
A lot of daily supply of water (humans can only live three days without it!) comes from rivers and the order of magnitude larger flows of groundwater, i.e., underground rivers flowing through soil and permeable rock formations. These channels continuously renew the quality of water by hydro-geological and biological processes in Nature, restoring it to health after each biological use of the water as it flows to the ocean. Every living thing uses water to excrete. Metabolizing the excreta is an essential part of water renewal.
Irrigation, sanitation, mining, dams, chemical fertilizers and cleaning products all work against natural water renewal. Irrigation to expand cultivation and human population in the Fertile Crescent killed the land permanently, because too many mineral salts accumulated in the croplands. Irrigation also killed the Aral Sea and stopped the flow of the Colorado River from excess evaporation. All irrigation affects the biology of groundwater flows and in general reduces safety and renewal capacity.
Water borne sanitation is not sustainable because it washes elemental nutrients downstream faster than they wash down from the mountains or get carried upstream by migrations of anadromous fish (salmon, herrings and eels that live in the ocean but spawn in fresh water); and also because it causes local nutrient excesses in rivers, lakes, streams, estuaries and river mouths where toxic algal blooms are festering and causing fish kills. For good water renewal we need to compost and recycle 100% of agricultural products back into the forest and crop soil, including all human, livestock and pet excretions from eating foodstuffs - and this is also necessary for a sustainable food supply!
Mining, refining and manufacturing consume and pollute a tremendous amount of water directly. Much of this has been exported the third world and developing countries, especially China; but the US and Europe are not excluded. We are still mining fossil fuels, with the majority of new mined energy sources coming from hydraulic fracturing, or "fracking". Any time you dig, drill or blast into the Earth you open up water channels to buried poisons. These subterranean hazards eventually work their way up to poison wells and groundwater above the mines, sometimes dozens of miles away. These poisons can take decades to surface, and last for centuries after the profits have been spent.
Fracking is by far the worst because it consists of penetrating impermeable layers that have been keeping the ecosystem safe for millions of years, drilling sideways through formations and then pumping down vast quantities of high pressure water to break up the rocks.
Other deadly water polluting poisons come in large quantities from Copper, Gold, Rare Earth and other strategic metal mining and refining - all the minerals needed for "green" technologies like Electric Vehicles, wind powered generators and rechargeable batteries.
Dams kill bio-active water renewal because they trap sediment in anaerobic layers, slow flows and reduce turbulence and aeration, prevent flooding that renews cropland, increase evaporation with large surface area artificial lakes and stop anadromous fish from returning to their spawning grounds. Aquaculture to replace fish stocks lost to dams and over-fishing causes water pollution and spread of diseases, and erases the species knowledge of where to go to lay eggs. Salmon were responsible for the fertility of six continents!
Mineral fertilizers that cause massive water pollution now feed half of humanity because of soil depletion. The remaining soil, where it has not dried up and blown away due to human folly in water management, is about half as thick as when we started agriculture, and deficient in the health of balanced nutrients and the vitality of bio-diversity.
Cleaning products are polluting, like the phosphates and surfactants in laundry and dishwasher detergents. Most household and industrial chemicals hurt the environment. There are no industries that would be profitable if the environmental costs were paid.
In summary, water as a renewable resource means planting 400 trees for every person and eliminating mining, burning, motorized transportation and sewer systems.
I built and maintained household water recycling systems at Pure Cycle from 1976–83 so I know what it takes, and I'm ready - are you?