Fresh water flows from the clouds to the oceans. It percolates through sands, gravels, and soils. It flows down creeks and rivers and out to seas and lakes. It grows our food and quenches our thirst. It sustains our lives. Only 2.5% of water on earth is fresh water and only 1.2% of that 3% of fresh water is surface water and 30.1% is groundwater. The remaining fresh water is locked away in polar ice caps. (a) The figure below from USGS depicts the location of Earth’s freshwater.
Unlocked freshwater will either be consumed, evaporate or flow down a river eventually reaching a lake or the ocean. The direction of flow depends on its area of origination. Water flows to rivers, lakes and oceans following a series of divides, watersheds and tributaries. For instance, North America’s continental divide is along the Rocky Mountains. This means that all water (and any foreign object with it, ie. plastics) originating east of the continental divide will flow east towards the Atlantic Ocean and everything west of the continental divide will flow west towards the Pacific Ocean.
On an even smaller scale than the continental divide are areas of ridges and hills that divide watersheds called drainage divides. Watersheds are “an area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel.” (b) In each watershed, water from rain runoff and snowmelt will flow into tributaries, or “small streams that feed into larger streams or rivers. The larger, or parent, river is called the mainstem. The point where a tributary meets the mainstem is called the confluence.” (c) The mainstem of the river will then feed into a lake, river basin or a river delta.
The flow of water not only pushes water in the direction of flow, but also pushes everything that the water carries like sands, sediments, rocks, plastic pollution, agricultural/farm animal & human sewage, micropollutants (hormones, pharmaceuticals), fertilizer pollution, metals, and oil pollution. These particulates cause reduced water quality and often turbidity. Turbidity refers to the relative clarity of water and is often related to cloudiness or haziness.
Pollution in the water creates problems to ecosystems. Fish and other aquatic wildlife might feed on the micro-plastics or absorb oil droplets found in waterways. When nutrients like fertilizers, poorly treated wastewater or sewage hit waterways they impact the chlorophyll content. Chlorophyll enables plants to perform photosynthesis and is essential for phytoplankton to exist. Chlorophyll tests are used to track algal growth, which is used to analyze the health of a body of water. Water with high chlorophyll content typically contains higher levels of nutrients, like nitrogen and phosphorus, which lead to a problem called Eutrophication, which leads to algal blooms or growth.
Eutrophication is caused by excess nutrients entering waterways. Eutrophication is spurred because like terrain, water can lack nutrients; however, while nitrogen is the lacking nutrient in soils, phosphorus is the lacking nutrient in water. Oftentimes water carries phosphorus pollution, more commonly from dish detergents and agriculture. When phosphorus hits waterways, it impacts the vegetative growth because the nutrient that previously lacked is now in excess. Excess nutrients can cause excess growth of aquatic organisms, usually in the form of algae.
The excess algal growth, or algal blooms, depletes the oxygen in the aquatic system, which can create areas known as dead zones (d). EOMap offers an interesting tool for monitoring chlorophyll and turbidity levels in certain areas of the world. Dead zones are areas of reduced oxygen that cannot support species. Dead zones commonly exist at the mouth of rivers, like the Mississippi River. The water flowing from the Mississippi River into the Gulf of Mexico contains fertilizers, which commonly cause dead zones.
Beyond analyzing water quality through tests like turbidity and chlorophyll content, it is also important to also consider other problems with fresh water like flow manipulation and human consumption patterns. U.S. cities have channelized waterways in order to control water flow, particularly in order to develop cities and neighborhoods. Channelized waterways are usually made of concrete, which destroy ecosystems and encourage faster water flow in order to control floods. However, floods within floodplains are beneficial for nutrient deposition into soils for farmland, are excellent habitats and control flooding.
Human consumption patterns also create problems with freshwater resources. In the United States the average toilet flush is approximately 3 gallons of water. Americans use an average of 17 gallons for a shower, 8 gallons to run a dishwasher, 1 gallon to brush teeth, 1 gallon to wash hands or face, and 25 gallons to wash a washing machine (e). If an American uses the bathroom 4 times in one day washing his/hands each time, takes 1 shower, washes the dishes, runs a load of laundry, and brushes his/her teeth twice with the water running, that American has used 68 gallons of water in one day. Normally, all the water is clean enough to drink without fear of disease and is fed directly to our faucet without the need to fetch the water.
Conversely, some villages in Africa survive on no more than 5 gallons per day to serve the needs of their family. The women often have to walk miles to fetch a bucket of water that is used for cooking, drinking, and washing. The water often contains water-borne diseases like parasites.
In addition to human consumption in the house, we also consume freshwater resources within our yards and gardens, and industries like agriculture, construction, drilling, and manufacturing. Oftentimes, homeowners or farmers will operate irrigation at peak evaporation times like 3PM, which is extremely inefficient for plants absorbing water. We also choose to grow agriculture in drought prone areas or water stressed areas like California. In addition, construction and manufacturing facilities use water to mix ingredients or to cool facility production equipment. If the water is utilized in a closed-loop system it reuses the same water; however, the water can be lost during production or expelled from the system with additional residues.
Freshwater is also used when fracking for natural gas. During this process thousands of gallons of water are mixed with hundreds of chemicals and pumped several feet underground. This pressure pushes the natural gas out of the ground and leaves the water and chemicals within the earth. This water is now tainted with harmful chemicals, which could cause serious concern for human health if consumed.
Alongside using water for natural gas, mankind also creates energy from water called hydroelectricity. While hydroelectric is a clean energy in terms of fossil fuel depletion, the dams constructed to create energy cause problems with watershed ecosystems, particularly with spawning fish like salmon who swim upstream to lay eggs. If a dam blocks a salmon’s breeding ground, the salmon will reproduce unsuccessfully, reducing the overall species population. A dam can decimate certain aquatic species.
While there are many problems with fresh water, solutions are not difficult to incorporate. Try to switch to phosphate-free detergents and cut back on fertilizer usage in yards or gardens. Always remember to rid your boat of any exotic species before launching it into a new waterway. Remember to water plants in the early morning or evening to reduce evaporation rates. Try to reduce at-home water consumption by turning off faucets, shortening showers, ensuring the dishwasher is full before running it and setting washing machine to the appropriate water level.
Installing a greywater reuse system is also useful for saving water. Greywater reuse systems capture all water used in the household, except water containing fecal material (toilet water = brown water). For example, greywater reuse systems capture the water used in sinks so that you can reuse the water in the garden (not on food). The particles in the water serve as useful fertilizers to gardens and reduce the demand on city water systems (f).
Having a rainwater catchment system can is also useful for home gardens and can reduce stormwater runoff. Rain gardens are particularly important in areas that lack a stormwater management system. Rain gardens are a mix of permeable gravels and native species with long roots. The rainwater runoff will hit the rain garden and permeate into the ground instead of running down a hill into a creek, river, lake, or bay. The long roots of the plant help absorb some of the pollutants as the rain moves into the groundwater (g).
Industries like agriculture can reduce water consumption by using greywater as well. You can tell if a farm uses greywater by looking for purple pipes! Using drip irrigation instead of broadcast irrigation also helps reduce water consumption. Some companies and even cities, particularly in drought prone areas like Dubai, Tel Aviv and San Diego, use desalination as a means for converting saltwater to freshwater.
Desalination removes minerals and salts from saltwater, making the water fresh for human consumption. While desalination is a great alternative to meet freshwater needs, it is also energy intensive and therefore costly. If possible, the better alternatives are to reduce water consumption or reuse greywater systems.
How Can Hemp Help?
Hemp is a hardy plant. It still requires water to grow, but it also can survive in most locations with little irrigation. This helps reduce water stress on rivers, streams and aquifers and mitigates excess runoff of nutrients into waterways.
Hemp’s fibers are also a beneficial filter. Synthetic fibers are currently used in filtering processes like desalination, but hemp could replace those synthetic fibers AND with a smaller cradle-to-grave environmental footprint!