Unit 3: freshwater systems and resources

Two arguments when commodifying water

1. Yes, privatization and economic gain
2. No, water is a human right and essential for survival

Drinking water is rare... how much of the earths freshwater is fresh, and how much is available?

Only 2.5% of earths water is fresh, but most is in glaciers and groundwater

Only 1% of freshwater is available as a resource

What percentage of freshwater is used for agriculture, household, and consumption

70% agriculture
65% of water consumption is used for toiletries in households
10% of water consumption is used for cooking and drinking

In situ

Value in its place

Climate change and hydraulic cycle changes

Higher ocean levels, higher salinization, thermohaline gradient

Earlier snowmelt, more runoff, drier summers, shift in rain belt

Warmer rivers, lower water in rivers, higher water in ocean

Freshwater systems

Rivers and streams through landscapes forming rivers creeks and brooks

Tributary system

Smaller river slowing into a larger one

Drainage basin / watershed

Area of land drained by a river and its tributaries

Oxbow

Extreme bend in river

Oxbow lake

A meander that has been cut off from the river

Floodplain

Area near rivers that floods regularly

Highly fertile

Riparian

Highly productive riverside areas because of the silt disposition from flooding

Mean Sea Level (MSL)

Average level water can no longer flow

Wetlands

Systems that combine freshwater and land

Freshwater marshes

Shallow water that supports vegetation

Swamps

Shallow water in forested areas, can be created by beavers

Bogs

Ponds with thick vegetation, early stage of succession

Importance of wetlands (3)

Slows runoff and erosion
Reduces flooding
Filters pollutants

Lake zones

Littoral zone
Benthic zone
Limnetic zone
Profoundal zone

Littoral zone

Water meets land, ringing shallow area of water

benthic zone (lake)

bottom of the lake

limnetic zone (lake)

Open water, light penetrates, primary productivity and photosynthesis

profoundal zone

deepest, coldest area of a large lake with little light and limited biodiversity

DO2 drops, Temperature drops

oligotrophic lake

Start formation, high DO2, low nutrients, algae starts to developed

eutrophic lake

Lake with a large or excessive supply of plant nutrients, mostly nitrates and phosphates.

Inland freshwater seas

large lakes that hold so much water, their biota is adapted to open water

Groundwater (two parts)

Precipitation that does not evaporate

1. Above water table (zone of aeration)
2. Below water table (zone of saturation)

Types of wells

Surface well, above water table
Bow wells, below water table, aquifers, probably cant see water

Water table recharged by...

Rain

Aquifers recharged by...

Aquifer recharge zones of groundwater depending on if its confined or unconfined

zone of aeration (unsaturated zone)

Spaces partially filled with water above water table

zone of saturation (phreatic zone)

Spaces fully saturated with water, below water table

Water table

boundary between saturated and unsaturated zones

Aquifer recharge zone

Area water infiltrates earths surface and reaches aquifers

confined (artesian) aquifer

water-bearing, porous rocks are trapped between less permeable substrate (clay) layers

confined aquifer

an aquifer surrounded by a layer of impermeable rock or clay that impedes water flow

Groundwater is ancient... average age is:

1,400 years

Diversion of water and its impacts

Alters rivers ecology, deprives environment of its water

Diversion for human use, hydro, consumption, and irrigation

Aral Sea

Diversion of water for cotton irrigation, lost 80% of water mass and 60,000 jobs

Economic and social sacrifices as well as environmental degradation

Dams

Prevents water from flowing, stores water in reservoir

Pros vs cons to dams

Pros:
Flood control, drinking water, recreational activity

Cons:
Water flow disrupted, fish migration altered, flooding, fisheries decrease, displacement

Dismantling dams

Costly, can restore riparian areas and reestablish fisheries

Only a few dams dismantled in Canada over 500 in US

Dikes + Leaves

Along banks of rivers for rising channels / flood control

Can increase floods with more sediment load

Environmental issues with dikes and leaves

Puts water in ecosystems not originally suited for, reestablishing the ecosystem community

Ramsay convention (1971)

Only half of the worlds wetlands remain since 1700

Ramsay convention is the global concern for wetland loss and degradation

How much has irrigation increased

Irrigation has increased by 70% since 1960 during the green revolution to produce more food crops

Flood and furrow irrigation

Only 45% of irrigated water actually absorbed into irrigated soils

Over irrigation leads to...

Water logging, salinization, and loss of farming income

Water mining

withdrawing water faster than it can be replenished

When aquifers become depleted...

Water table decreases
Salt water intrudes coastal areas
Sink holes can occur
Wetlands dry up

Dealing with depletion of freshwater, supply vs demand

Supply up: transported, forcibly taken from weak communities
Demand down: politically difficult, better economic return, less eco + social damage

Desalinization

the removal of salt (especially from sea water)

Distilling

evaporates and condenses water Vapor

Reverse osmosis

Forces water through membranes to filler out salts

Xeriscaping

Landscaping with plants adapted to dry environments

Covert crisis

Invisible pollution of groundwater

Point source pollution

Discrete location from which pollution is directly produced

Non point source pollution

From multiple cumulative inputs over a large area

Pollution takes many forms:

Pollution is the release of energy or matter into the environment that causes undesirable effects on health or well-being for humans or other organisms

Five types of water pollution (NPTST)

1. Nutrient pollution
2. Pathogens + water born diseases
3. Toxic chemicals
4. Suspended matter
5. Thermal pollution

Nutrient pollution + solutions

From fertilizers, farms (runoff), sewage, lawns

Leads to eutrophication

Solutions:
Phosphate free detergents, treat waste water, plant vegetation (limit erosion), reduced fertilizers

Pathogens + water born diseases + solutions

Enters water from improperly treated animal waste / fecal matter

Causes more human health problems than any other pollution

Fecal coliform bacteria, or other pathogens like hepatitis A

Solutions
Treat sewage, disinfect drinking water, public education, government regulations

Toxic chemicals + solutions

From natural and synthetic processes

Poisons animals and plants, poor human health, alters aquatic ecosystem

Solutions
Enforcing regulations, modifying industry processes, modifying purchasing decisions

Suspended matter + solutions

Sediments that impair aquatic ecosystems from clear cutting, mining, or poor cultivation practices

Dramatically changes habitat, fish may not survive

Solutions
Better manage farms and forests, avoid large scale vegetation disturbances

Thermal pollution + solutions

Warmer water holds less DO2 as temperature increases

Industrial cooling heats water, also removing stream side mass heats water

Water that's too cold can also kill fishes

Dramatic fluctuation since temperature can kill fishes and aquatic organisms

Three indicators for water quality

1. Biological
2. Chemical
3. Physical

Biological indicator

Presence of fecal coliforms bacteria or other diseased organisms

Chemical indicator

PH, nutrient concentration, taste, odour, hardness, DO2 levels

Physical indicators

Turbidity, colour, temperature

Groundwater pollution difficult to detect because...

Out of sight out of mind mentality

Retains contaminants for prolonged periods of time, DDT still found in North America although banned 40+ years prior

Some toxic chemicals naturally occur some are human made

Natural:
Aluminum, fluoride, sulphates

Human:
Pathogens, hazardous waste, septic tanks

Canadian Environmental Protection Act (CEPA)

A broad Act passed in 1999 to set standards aimed at preventing pollution and protecting the environment and human health

Fisheries act

The federal law that regulates fishing and the harvesting of marine plant life, and protects marine habitats.

Waste water

Water that's been used by people in some way

Septic system

Separate solids and pils from water, need occasional pumping

primary treatment of sewage

Physical removal of contaminants in settling tanks (clarifiers)

secondary treatment of sewage

Water stirred and aerated for aerobic bacteria to degrade organics

Then treated with chlorine and piped into rivers or ocean

Effluent

liquid waste or sewage discharged into a river or the sea.

Sludge

Solid waste material from wastewater

Remediation

Removing pollutants from water

Pump and treat

Pump out water, treat it, and return it

Air Sparging

Injecting oxygen where contaminants adhere to air bubbles

Natural and artificial wetlands can cleanse wastewater

After primary treatment, water in pumped into a wetland where microbes decompose remaining pollutants