water management schemes

Water restoration

• A sustainable bottom up approach

• Water restoration involves rehabilitating damaged environments such as lakes, rivers and wetlands to their natural state

• This involves using strategies such as:

• Remeandering: where straightened river channels are restored to their natural paths, allowing habitats to form again and reducing flood risk

• Replanting of vegetation: trees and shrubs are planted along the rivers to increase processes such as infiltration as well as reducing soil erosion, improving the quality of the water

• Removing barriers to the floodplain: this allows the speed at which water flows in a river to slow, reducing cloudiness of the water and allowing nutrient cycles to take place which naturally filter the wate

Pros of water restoration

• increase biodiversity due to habitat restoration

• Increases water quality

• Attacks the problem of water quality at the source

Cons of water restoration

• sometimes there can be a lack of economic sustainability due to the environmental focus

• The scheme doesn’t address issues of pollution e.g agricultural fertilisers, or urbanisation

• May involve social invovlemt which not every immunity can offer

Examples of water restoration

• bottom up scheme - along Mithi river in Mumbai, Earth5R, Indias largest environmental organisation.

• India’s largest environmental organisation, trained over 3,000 citizens in clean-up techniques along the river as well as environmental auditing. This led to over 180,000 KG of waste being removed from the river and a 15% reduction in plastic waste of the river.

• Native plant species were reintroduced and allowed the return of wildlife species which had previously disappeared.

• A large-scale, top down example: the US Army Corps of Engineers successfully restored the Kissimmee River, Florida. More than 100 square km of river has been restored by backfilling 22 miles of canal, restoring 22,000 acres of wetlands and removing water control structures such as locks. This has led to an increase in biodiversity, an improvement of water quality flowing to nearby lakes as well as reducing toxic algae blooms caused by eutrophication

Pros of integrated drainage basin management

• improved water quality since it promotes responsible land and water use

- ecosystem protection balances human and environment needs

• social equity - ensures water is fairly allocated which also reduces conflict

• improved health due to access to clean water

• Provides jobs

• Make the water basin more efficient in supplying local communities wiht sufficient water

Cons of IDBM

• costly and time consuming - requires lots of people to make a successful plan and can take a very long time to action all sections within the plan

• political challenges and conflicts - trans-boundary river basins can result in different priorities which can’t all be met, resulting in some areas being angry

• it can sometimes focus solely on water and dismiss other important human issues such as energy and food

Example of IDBM

Rapid population growth, especially in north east China where 93% of the country’s population lives, have led to increased environmental threats to the river basin ecosystem It is home to many species, including the Siberian tiger which is threatened by the uses of the river It is currently being used primarily for hydroelectric power generation. By 2019, there were over 100 dams built Following the IWRM framework, a strategy is being put into place to balance the electricity needs of the river, as well as the river’s sustainability and purpose in the ecosysteM

Integrated drainage basin management scheme

a holistic approach to managing water, land, and related resources within a river basin to maximize economic and social benefits while protecting the environment

Colorado drainage basin management scheme

Being 637,000 km3 long, it faces struggles when being

managed

The population is also growing rapidly which brings about more challenges

Climate change is also creating drier conditions and changing river levels

An agreement was made in 1922 to agree to share out water based on demand in

1956

In recent years, due to population growth, there has been disputes between the

states due to not enough water supply so they have started to make alternative

plans, such as Arizona recharging its qualifier in higher discharge year

Mega dams

• hard engineering approach

• Usually 100m high and produce 40 megawatts of power, and can hold 1 km3 of water in their reservoir

Advantages of mega dams

• hold back huge amounts of water, which is helpful to store water during times of surplus to ensur there’s enough water during times of deficit

• Ensures a consistent flow of water in the river all year round and the water is trapped in wet periods and released in dry periods

• Can be multipurpose ( store water, provide irrigation and enable power regeneration) e.g hoover dam in Colorado irrigates more than 1 million acres of land

• Store 15% of annual runoff globally

• Construction and maintained of mega dams employs people

• Providing renewable energy to help combat climate change

Cons of mega dams

• Are very expensive only HICs or countries with sport from HICs can afford them

• Hinge evaporation losses

• Disrupt don’t stream movements of silt ( an important fertiliser for farmland further downstream)

• Often displacement of large numbers of people e.g often involve the displacement of large numbers of, often poor, people -> for example, the construction of the Three Gorges Dam on the Yangtze River in China flooded over 1500 villages and towns to form the reservoir, as well as displacing 1.3 million Chinese resident

What approach is a Mega dam

Top down

Examples of mega dams

Hoover dam

Three gorges china

What is desalination

• Desalination is the removal of salt from sea water so it can be used as a water source

• is a hard engineering scheme top down

• Sea water is heated until the water evaporates then the water vapour is condensed → freshwate

• Can also be achieved through reverse osmosis = seawater is passed through membranes to remove the salt

Pros of desalination

supply isn’t dependent in the climate - reliable and consistent

Eliminates need for importation

Reduces pressure on natural water sources

Cons of desalination

• high costs

• Require high levels of technology

• Produces waste water that requires safe disposal called brine water

● High energy consumption

● Water quality concerns as some plants use chemicals

● Intake of water often harms fish and other aquatic

What is water transfer scheme

A water transfer scheme is a system that moves water from an area of water surplus to a an area with water deficit. 

This is achieved by creating infrastructure like canals, pipelines, reservoirs and aqueducts to transport the water, often over long distances.

 These schemes are used to balance water supplies for populations, agriculture, and industry in different regions.

Involves the diversion of water from one drainage basin to another, either by diverting a river or building a canal between one drainage basin and another.

Pros of water transfer schemes

• More water is available in the receiving area so water security is increased

• Increases the amount of irrigation and agricultural productivity 

• May deal with issues arising from climate change 

• the volumes of water being transported may be controlled to suit seasonal needs 

• highly effective and designed for small scale use 

• greater levels of political cooperation between countries and regions 

• greater security against minor imbalances between supply and demand

Cons of water transfer scheme

• The source area loses a large proportion of its water ( increased water stress in source loacation) 

• The source river has a lower flow and therefore the pollution within it increases e.g nitrate eutrophication increases 

• can create water scarcity in the source region

• acts as a pathway for introducing alien species into new river environments 

• Damages fish stocks  

• receding area may be more inclined to use unnecessary amounts of water ( like a golf course) 

• can increase salt water intrusion 

• rivers can become heavy with sediment and so decrease rate of flow 

• infrastructure is expensive to build, maintain and dates environment

Examples of water transfer uk

 from Welsh reservoirs to Liverpool and Birmingham; form the Lake District to Manchester and from kieldrr water to the river tees.

Example of water transfer India

An example of a top down scheme in China: South - North transfer project 

The south of china is rich in water resources but north experiences water deficiency, this project plans to transport water from the south to the North, starting in 2003 its planned to take 50 years, US 100billion dollars. Incoelces building 1300km canals across eastern, middle and western china; which link the 4 main rivers: Yangtze, Huai,Hai and Yellow. It will transfer 44.8 billion cubic meters of water each year. This is a top down scheme because it is being run by the government which are funding 60% of the scheme, and the ret will come from coal authorities which will charge the domestic ad industrial users. 

Concerns for this scheme are high due to potential ecological, Environmetantal issues, resettlements and worsening water quality ( the Yangtze River is already polluted and the yellow river is undrinkable) . part of the Central Route construction, the height of the existing Danjiangkou Dam on the Hanshui River (a tributary of the Yangtze River) was increased by about 15 metres to allow more water to be stored in the reservoir behind it. This flooded more land, which destroyed habitats and reduced biodiversity.

Pros of water transfer china

• over 100 million people have benefitted from this scheme 

• provides clean water to over 20 cities 

• Means industrial development can increase in the north and the countries wealth can continue to grow 

• scheme provides water to irrigate farmand so more crops can be produced 

• should help to stop over abstraction in the north and stop land subsidence