Evaluating Sustainability Of The Three Gorges Dam Environmental Sciences Essay

The purpose of the project is to establish a holistic sustainability appraisal for the Three Gorges Dam, TGD, and provide reasoned recommendations to improve the sustainability of the project as a whole fully considering the interdependency of the current processes within the system. To enable the sustainability assessment to be carried out, boundaries have been established to limit the temporal and spatial scope of the assessment. This report will assess the sustainability performance of the TGD, with focus on the projects effect on the surroundings and the Chinese people during the construction and the operational phase of the project. In doing so the report focuses on the political, economic, social, technical and environmental processes within the system, creating a framework of interdependent processes from which sustainability issues can be identified and opportunities for synergy improvement established. The recommendations of this report will attempt to offer holistic improvements to the sustainability of the TGD and also future hydroelectric dam projects within a wider system boundary.

Case History

China’s hydroelectricity program is one of the most ambitious in the world, with over 20,000 large dams currently in operation, close to that of the rest of the world combined [1] . This ambition has led to the completion of the TGD, currently the largest dam in the world. The China Three Gorges Corporation, CTGPC, a state owned company charged with managing the construction, operation and maintenance of the dam, began operations with a clear purpose “To build a first-class hydropower plant to stimulate the growth of the local economy, improve the local environment, and benefit resettled residents”. This modern purpose however is predated by an original vision by Yat-sen Sun, the fore-most pioneer of nationalist China in 1919, who planned to “improve the upstream from here” suggesting “a dam should be set here to let ships go downstream and use the water resource as power” [2] . The Three Gorges Dam had become a national goal for almost 80 years and was realised upon the dam’s completion in 2009.

Now complete, the concrete gravity dam stretches 2,309m across the Yangtze River near the town of Sandouping, located in the Yiling District of Yichang, Hubei province, at a height of 185m. The construction of the dam took 16 years at an official cost of $25 billion, although the exact figure is widely regarded to be significantly higher than this sum [3] . The construction of the dam was carried out in three phases;

Phase 1 (1993-1997) – Preliminary design review, formation of CTGPC and river closure

Phase 2 (1998-2003) – Construction of dam body, reservoir started impoundment and first generator officially integrated into the power grid

Phase 3 (2004-2009) – Last generating unit installed, dam body completed, roller compacted cofferdam removed so TGD began blocking the Yangtze River creating the reservoir, dual-line five stage ship lock completed. All construction tasks set in the projects initial design were completed

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Completed in 2009, the TGD provides; significant benefits for flood control to areas surrounding the Yangtze River, Clean hydroelectric energy production, increased navigability of the Yangtze River for trade and ecological water replenishment for the middle and lower reaches of the River [4] . Significant values for these benefits include; a flood frequency improvement from once in every 10 years to every 100 years significantly improving the safety of inhabitants downstream, production of 84.7 TWh of ‘clean’ electricity (equivalent to burning 50 million tons of coal), increase from 10 million to 60 million tons in annual passage capacity and reducing freight costs by 1/33. However, China’s significant experience in the field of large hydraulic dams does not necessarily equal success as there are widespread criticisms of the TGD for the social and environmental implications caused by its installation, such as the large scale relocation and resettlement of 1.24 million valley inhabitants [5] and significant disruption to the natural environment.

The importance in identification of such sustainability issues of the TGD are further compounded as the dam is proposed to become a part of a cascade network of six large hydroelectric dams along the Yangtze River, many of which are currently under construction. As a result it is not only important to appraise the sustainability of the TGD to provide benefit in this case, but for knowledge gained from the TGD to be utilised in the proposed dams schemes residing within similar economic, social, environmental etc conditions. Hence, where possible, this report will attempt to recommend solutions that could be used to benefit similar systems beyond the boundary of this report.

Stakeholder Analysis

Due to the complexity of the system being analysed, a clear understanding of the key stakeholders’ desires and motives for the project must be established. Understanding the interest and respective power of each stakeholder will allow for dynamic solutions to recognise the needs of the ‘interested’ yet less influential stakeholders and target the stakeholders with the most influence to instigate change. An indicator system is also applied to each stakeholder to illustrate the domain in which their objectives for the TGD apply.

Power/influence

High

Low

HighCTGPC

Shipping companies

Electricity companies

Local farmers

Employees

Insurance companies

Forced re-settlers

Local Council

National Government

Investors

Human rights organisations

Environmentalists

Contractors

City dwellers

Archaeologists

Interest

Low

Figure 2. Stakeholder Interest and Influence

Factor

Symbol

Economic

£

Social

…

Political

‡

Technical

ƒ‚

Environmental

ƒ¼

Stakeholder

Objective

CTGPC

Fulfil dams purpose

Investors

Make money

National Government

Flood protection/clean energy production

Local Council

Increased trade, successful relocation strategy

Forced re-settlers

Fair compensation/ right to speak

Insurance companies

Reliable and safe operation

Employees

Salary/job satisfaction

Electricity companies

Reliable supply of energy

Environmentalists

Minimise damage to environment

Human rights organisations

Fair and consistent treatment of those effected

Shipping companies

Reliable access to shipping routes

Contractors

Future developments/maintenance

Downstream farmers

Reliable water supply

Archaeologists

Preservation of historical sites

City dwellers

Supply of cheap clean energy

Table 1. Stakeholder Objectives

System Architecture

To effectively assess the current sustainability of the TGD, a comprehensive understanding of the processes present in the system throughout construction and the operational phase must first be established, paying close attention to the interdependency of these actions.

A PESTE framework (political, environmental, social, technical and economic) has been chosen to categorise the processes in the system highlighting the significant positive and negative emergent properties brought about by the combined actions of the processes identified. The framework attempts to guide the user through the layers of the system illustrating key sustainability issues and allowing the user to trace the origin of processes through the use of positive and negative pathways. The architecture can be seen in figure 2.

By 1/3

1 in 100 years

Key sustainability issues

Positive path

Positive Emergent Properties

Negative Path

Negative Emergent Properties

Key

4-6 million

3%

Figure 2. PESTE Architectural Framework

4.1 Architecture Appraisal

The architecture has illustrated several positive and negative emergent properties of the current system. In many cases the negative emergent properties have been driven by sustainability issues deemed to possess significant potential for holistically improving the sustainability of the system.

Through the use of the negative path indicators it is possible to trace the source of these sustainability issues throughout the system. Interestingly, this trace reveals that many of the subsequent negative emergent properties of the system originate from two key core processes: Relocation and Resettlement and Reservoir creation. However, these two are interrelated and so consideration should be shown to the consequences of actions on each of these processes.

In some instances the architecture identifies a process that leads to both positive and negative outcomes highlighting that the processes in themselves are complex issues that must be considered in unity as well as part of the ‘bigger picture’.

Measurement Regime

A measurement regime has been introduced to, where possible, quantify the scale of the issues presented in the architecture in order to firstly gauge the severity of the issue, and secondly, illustrate areas where possible improvements could be made. The regime covers both blue and green sustainability issues to aid in gauging the overall sustainability of the TGD as a business entity and its environmental sustainability. To provide a comparison, the TGD has been measured alongside the Itaipu Dam which is situated across Brazil and Paraguay. This dam project was selected as it is currently the second largest hydroelectricity capacity dam in the world and is situated outside of China to facilitate opportunity for outside influence on the TGD. The measurement regime is shown in table 2.

Three Gorges Dam

Itaipu Dam

Purpose

“To build a first-class hydropower plant to stimulate the growth of the local economy, improve the local environment, and benefit resettled residents”

“To generate quality electricity via socially and environmentally responsible practices, and to foster sustainable economic, tourist, and technological development in Brazil and Paraguay.”

Type:

Location:

Generating capacity:

Area flooded:

Completion date:

Number of people relocated:

Concrete Gravity

Yangtze river, China

22,500MW

632 km2

2009

1,240,000

Hollow core Concrete Gravity

Parana River, Brazil & Paraguay

14,000MW

1,350 km2

1991

50,000

Official Cost of Scheme

$25bn

$18bn

Payback Period

19.2 years

~ 15 years

Operation and Maintenance

$0.92bn

$1.72bn

Profits 2009

$1.97bn

~ $2bn

Power produced 2009

79.4 TWh

91.6 TWh

Percentage of countries electricity supply

3% China

25% Brazil, 78% Paraguay

Number of people relocated /km2 flooded

1,962

37

Power produced/ km2 flooded in 2009

0.12 TWh/km2

0.06 TWh/km2

kg CO2 saved /annum

1.26 x 1011

1.54 x 1011

Actions to reduce ecological impact

‘Dalaoling plant protection zone’

‘Chinese Sturgeon Nature Reserve Project’

‘Ancient Woods Protection Project’

‘Mymba Kuera’ – minimise affects of flooding on fauna

‘Gralha Azul’ – minimise deforestation

Table 2. Measurement RegimeActions to reduce silting of dam

Plan to construct four additional dams upstream to act as hydroelectric siltation dams

Conservation monitoring program designed to identify areas with greatest sediment production and mitigate cause of excess sedimentation

Green Sustainability

Blue Sustainability

Appraisal

The systems architecture has identified a significant array of sustainability benefits of the TGD, such as the positive emergent property of an improved local economy, which has undergone a considerable transformation as the GDP for 20 surrounding counties has increased 259% from 1996 levels. [6] However a significant number of environmental and social issues have detracted from the TGD success as a sustainable system.

The current state of the Three Gorges Dam has seen many of the sustainability issues arise as a consequence of years of development. As such, many of the fundamental causes of these issues identified in the architecture cannot be mitigated directly as they are an integral process in achieving the ‘purpose’ of the system. Hence this report categorises the sustainability impacts as: Impacts that can be mitigated through action, and impacts that cannot be mitigated. The opportunities for sustainability and synergy improvement for the TGD will be sought from recommendations that will focus on impacts that can be mitigated without compromising the purpose of the project. Further recommendations will be provided for impacts that cannot be mitigated, for use in similar large scale dam construction.

As a large hydroelectric dam, the TGD lends itself to be directly compared to other dams of its type. As can be seen from the measurement regime, the TGD excels in some instances such as the power produced per km2 flooded, which in turn reduces the environmental impact caused by flooding a larger area for the same power production. However in some cases the Itaipu Dam provides more significant benefits such as the proportion of the country’s energy supply the dam provides. However, this higher proportion results in increased dependence which can lead to severe crises in the event of a drought.

The Relocation and resettlement project for the TGD was officially completed in 2008 [7] , with the relocation of 1.24 million people from the Three Gorges area5. However government officials also announced in 2007 “at least 4 million people from the Three Gorges Reservoir area are to be relocated to cities in the next 10 to 15 years” [8] contradictory to the official statement. As a result, relocation and resettlement remains a significant sustainability issue for the Three Gorges Project.

The Three Gorges relocation strategy is controlled and implemented by the national government [9] , creating a top down process which resulted in the exclusion of major stakeholders when making key decisions. Many of these stakeholders are illustrated in figure 2, such as the re-settlers themselves. Identifying and including the key stakeholders in decisions would ensure the needs of those affected by the decisions are fully considered resulting in many of the significant sustainability issues illustrated in the architecture being improved upon.

Perhaps the most significant parent process for many of the sustainability issues identified in this report is the creation of the Three Gorges Reservoir, TGR. The system architecture demonstrates that many of the identified sustainability issues could be resolved by direct manipulation of the reservoir characteristics such as the size, level and volume of water retained. However, as this would cause significant detriment to the operations of the dam, opportunities for sustainability improvement will be sought from subsequent processes that have been identified.

Increasing silt deposits in the reservoir has significant potential to cause major environmental damage and put human lives at risk. This has prompted the Chinese Government to initiate the construction of an additional four dams upstream of the TGD in an effort to control river sediment flow. However this offers only a short term solution as the life of a siltation dam is usually short [10] ; hence a long term solution should be sought.

Since its creation, there have been 91 cases of landslides in the region of the TGR during which 36km of shoreline has collapsed into the reservoir resulting in a large number of deaths and significant property damage5. Although a government led early warning system is in place, there is opportunity for community involvement in the identification of hazardous regions.

Conclusions and Recommendations

There has been considerable investment, RMB 349 million ($53.6 million), by the Chinese Government for the environmental protection effort of the Three Gorges area [11] . This ongoing effort has been successful in many instances by providing symptomatic solutions to the immediate problems at hand. Examples of this include the further relocation of residents believed to be in high risk areas for landslides. However, more comprehensive and fundamental solutions should be sought to target the true cause of the problem and not the subsequent symptoms, to limit the need for symptomatic solutions.

Providing such solutions to a system as complex as the TGD presents a significant challenge as many of the issues would have been more easily controlled if identified prior to construction. This in itself however, creates opportunity. The TGD should act as a valuable instrument in investigating the effects of large hydroelectric dams and will also be used in this report to suggest actions applicable to the prospective dams upstream of the TGD. It must be noted also that the solutions provided in many instances will require time for the benefits to become apparent as actions and consequences are separated by a delay. [12] Recommendations and mechanisms for implementation are shown in table 3.

#

Recommendation

Mechanism for implementation

1

Selective Coarse Sediment (CS) dredging of the reservoir to relieve sediment build-up

Removal of coarse sediment by dredging can significantly reduce the sediment build up in a reservoir [13] 

Dredged sediment should be released downstream to enhance fertility downstream

Alternatively dredging could prove profitable as sand is a desirable building material.

2

Further investment in the involvement of communities for early warning landslide system

Develop a region wide community based scheme educating locals how to identify potential landslip regions

establish an efficient communication network to distribute knowledge quickly and effectively

3

Identification and involvement of all key stakeholders from project conception to completion.

The National Government must promote effective channels of communication to promote stakeholder engagement

Stakeholders with high interest/low power (re-settlers, etc) must be heard to establish needs to be provided by stakeholders with high influence

4

Development of a holistic and dynamically flexible relocation program

Needs of affected stakeholders fully considered

Contingency allowance for unexpected costs

Strict monitoring of cash flow and implementation

Define purpose of program to meet the needs of those effected

5

Comprehensive assessment of the potential impacts of reservoir creation prior to construction

Stakeholder involvement key for this process

Develop worst case scenarios and mitigation strategies for fast and effective response

Create a dynamic model for assessment to adapt to variable conditions

Strive for identification of ‘unknown unknowns’

6

Use nature and scale of issues as an opportunity for research and development

Large scale research carried out into the social and environmental effects to deepen scientific knowledge of large hydroelectric dams.

Particular fields should include: land stability, effect of reduced sediment flow downstream, welfare of re-settlers

Integrate findings into national strategy for large hydroelectric dams

Table 3. Recommendations