Groxie

This is the first of three articles dedicated to water (here are the second and third parts). I did a cursory post on water conservation a while ago. I’ve been studying the state of freshwater all summer, and now I am convinced that we need to do more than take short showers and avoid washing our cars. This issue is of critical importance—we are running out of clean water! To understand the problem, you need to have a good grasp of general water issues.

Water 101

Only 3% of the water on Earth is freshwater, and only .01% is available for use by humans. While it is a renewable resource, we are consuming it and contaminating it faster than it can recover. Water scarcity is a global problem, but each area is faced with different supply and different obstacles. Solutions must be developed at a local or regional level.

There are two types of freshwater that supply the world’s water demands:

Surface waters

• Surface waters are primarily made up of lakes, streams, polar ice caps and glaciers.
• 70% of freshwater is locked up in polar ice caps glaciers.
• Streams and lakes are fed by springs, smaller streams, run-off, and precipitation.
• Streams naturally experience periods of flood, which help control invasive species, transport sediment, and maintain the river channel.

Ground waters

• Ground water refers primarily to aquifers. Aquifers are underground rock formation saturated with water.
• Some aquifers can take hundreds of years to recharge, others take only a season. Recharge depends on many factors, one of which is how fast we are withdrawing water.
• 98% of usable freshwater is groundwater.

Surface water and ground water are connected through the water cycle, so events affecting one source of water are not always limited to that source.

Water Quality and Quantity

Droughts account for some of the water scarcity we are currently experiencing, but we certainly aren’t helping the situation. Here’s a quick rundown of some of our worst offenses.

Dams

Dams are often used to hold water in reservoirs or to help generate electricity. Unfortunately, these services come at a high cost to the species living in and along the river, and often the river itself is compromised. Dams alter the temperature and sediment content of a river, harming freshwater species and contaminating the water. Dams also change the flow pattern of a river, and alterations of instream flow can have devastating effects. The American Society of Civil Engineers recently determined that the number of unsafe dams in America is over 3500.

Point source pollution

Point source pollution can be tracked to a specific source. The Exxon Valdez spill is an extreme example of point source pollution, but in regards to freshwater it typically refers to an industrial or municipal treatment center discharge pipe. This type of pollution is easier to detect and regulate than non—point source, but most of these discharges flow straight into streams with no regulation.

Non—point source pollution

Non—point source pollution cannot be traced to one source, and is often delivered to streams through runoff. Runoff from farms, construction sites, and other chemical laden areas can contain fertilizers, pescticides, sediment, oil, bacteria, nutrients, other toxic chemicals that contaminate the water. Non—point sources are very difficult to monitor or regulate.

Impervious surfaces

Impervious surfaces are replacing natural landscape at an increasing rate. Roads, parking lots, roofs, and sidewalks are usually comprised of impermeable materials. This results in less precipitation seeping into the ground to recharge aquifer; because water cannot permeate the ground, it flows in greater amounts to the nearest stream, carrying with it chemicals from the surface of the parking lot or road. An increase in impervious surfaces has led to more frequent flooding, especially in urban areas.

Depletion

In many areas we are withdrawing water from streams and aquifers faster than it can recharge. This depletion reduces water pressure and can lead to saltwater intrusion—a problem that already exists in many areas of the world, including the U.S. Saltwater intrusion can lead to the contamination of aquifers, sometimes forcing users to abandon wells. Once saltwater intrusion has occured, it is extremely difficult (sometimes impossible) to recover the groundwater source.

Tune in next time

Next post I’ll delve into some region—specific problems, as well as some of the laws and regulations that govern water use and maintenance. After that I will finally tackle some of the solutions that are being developed here and elsewhere and what you can do to help.