Vietnam has a relatively dense network of rivers. This includes the system of Red river and Thai Binh river (in the North); system of Ca river and Ma river, system of Han river, Thach Han river and Thu Bon river (all in the Centre); and the system of Mekong and Dong Nai river in the South. Due to the influence of climate, rainfall in Vietnam is quite high, with an average annual rainfall of 1800-2000 mm, which is the main source of supply for the surface and ground water.

---

Specific characteristics of water resource and water supply in  Vietnam	Surface water Underground water Water usage and demand Scarcity of water
Inland water  environment   pollution	Pressure Status and trend Water of rivers in the South Pollution of underground water Responses to protecting the inland water environment

Specific characteristics of water resource and water supply in Vietnam

Surface water

Topography and climate are the two main factors that affect Vietnam's water resources. Rainfall in Vietnam is unequally distributed over the seasons and regions. In the wet season, there are frequent floods while drought is a regular feature in the dry season.
Two historic floods occurred in November and December 1999 in the Central provinces of Quang Tri, Thua Thien – Hue, Quang Nam, Quang Ngai, Binh Dinh and Binh Thuan. The rainfall during this time  reached 2000 mm.
The mountainous topography adds considerable potential for hydropower and water storage, but at the same time it also causes rapid flood concentrations and intensifies soil erosion.

Surface water resource Total  annual average water volume is 880 bill. m3, 75% of which  is  from the Red river and Mekong river basins. However, Vietnam is at the end of the lower sections of the Mekong, Ma, Ca and Red rivers; For example, over 90% of Mekong river basin is outside Vietnam territory (Table 4.1). Water volume formed in Vietnam territory is about 325 billion m3/year. Therefore, it is very difficult to have water, especially in the dry season when utilisation by upstream countries is not in the control of Vietnam. As a result, Vietnam has learnt to conserve water, according to the seasonal needs, especially when the demand is high.

The average water volume per capita is fairly high in comparison with other countries in the region

Comparison of water potentials of countries in the region

Vietnam has built many reservoirs like: Thac Ba lake, Hoa Binh lake, Tri An lake, Yaly lake, and Dau Tieng lake, etc. Development of water resources requires wide coordination among the various regions.

Catchment area and discharge of Major River Basins

Source :  NHS/HP (1992) and MWR/Nippon Koei (1992)[11,13].

(*) - Percentage of the flow in comparison with total flow in Vietnam

(**) - Percentage of the flow of river which is located in Vietnam

[Top]

Underground water

Underground water resource in Vietnam is concentrated in some main aquifers (with moderate and large scale exploitation).

In addition, there are some other specific underground water resources such as mineral water and hot springs. So far, 350 mineral water and hot spring sources have been discovered.

Underground water resource Calculations of the Institute for Water Resource Research and Planning in conjunction with international organisations (WB, ADB, UNDP, 1996) indicate that the potential water reserve of the above- mentioned reservoir  is about 48 bill. m3/year (131.5 million m3/day) and the estimated exploitation reserve is approximately 6- 7 billion m3/ year (17- 20 million m3/day). Every year about 1 billion m3 can be exploited (2-3 million m3/day).

As far as the quality is concerned, all regions in the country satisfy the demand of utilisation, especially water for household use. In the North and South deltas, changes in the quality of ground water are more complex due to the alternation of fresh and salt water aquifers. The phenomenon of water with high iron or alum content is also frequently encountered.

In general, quality of ground water is good except in areas having high content of iron and manganese, which requires treatment before utilisation. However, infiltration of the sea water exerts negative influences on the quality of water in some coastal areas. Evidence of some pollution is found in areas near Ha Noi, Mekong River delta and Ho Chi Minh City (due to over exploitation).

[Top]

Water usage and demand

Water is used in agriculture, industry, hydropower, transportation and for domestic purposes.

Trend of water consumption demand in Vietnam

In general, it is estimated that by 2030 the level of water exploitation will be less than 100 billion m³/year, which is much less than 880 billion m³/year of the surface water reserve. However, there is always a shortage of water in many rivers and streams during the dry season [13].

Water in the rivers and streams is also used for fishery purposes and for preventing salt water infiltration in the coastal areas.

a- Exploitation of surface water and ground water to meet living, urban and industrial needs:

Vietnam has over 623 towns.  Most of the cities or municipalities in provincial centres have centralised water supply systems. The underground water resources exploited take about 30% and Ha Noi uses 100% of underground water for domestic and industrial purposes. However, the percentage of population in each town that has access to water supply is still low (60-70%).

Capacity of the existing 190 water factories was 2.6 million m³/day in 1998. According to the trend of water supply for the urban areas to the year 2020, water demand for the urban areas to the year 2010 will be 4.5 million m³/day and for industry will be 3.3 million m³/day so that the total will be of 8.8 million m³/day. By the year 2020 total of demanded water will be 15.94 million m³/day, of which 7.59 million m³/day will be for urban areas and  8.35 million m³/day for industry[6].

b-   Water supply in rural areas

Since 1982, the rural water supply program is being implemented with the assistance of UNICEF in 61 provinces. The programme had supplied clean water to 24 million people in the rural areas by 1997. The programme accounts for more than 170,000 water supply works, 70% of which are related to ground water and the rest mainly rain water. Surface water accounts for only 1% [4].

On an average over 30% of the rural population is supplied with clean water, the lowest is in the Northern mountains (about 15%) and the highest in the Central Coast and Southern Central Coast (about 45 % ) [4].

In many mountainous areas the lack of water for household activities is a serious problem, particularly during the dry season [4].

Underground water is also used widely for watering farm products and industrial plants like coffee, pepper, etc. and this has brought high economic effectiveness.

[Top]

Scarcity of water

a-  Surface water : Surface water is mainly concentrated in some areas, during certain months and with different  quality. During 6 months of the dry season, water in rivers decreases considerably, quality of the surface water becomes worse due to salt intrusion and reverse absorption from alum soil. This results in the water having a high content of ferrous and aluminium.     

The surface water resource is relative stable in the south in comparison with other areas in Vietnam, but shortage of surface water still occurs in the Tien Giang and Hau Giang rivers and the canals. For instance in 1998 and 1999, water levels in the rivers were lower than those of the previous years by 0.1 to 0.2m.

Desertification is observed in 4 areas in Central Vietnam [7]:

In Quang Binh- Quang Tri- Thua Thien Hue and in Quang Nam- Quang Ngai- Binh Dinh: Dry season extends from January to August. River flows are very low, infiltration of salt water is severe in the coastal areas and sand dunes occur in some coastal areas. Drought and soil erosion also occurs in the low mountainous areas. The most serious phenomenon is desertification after the flood in the lower section of rivers and drought and erosion in the mountainous areas.

Phu Yen- Khanh Hoa and Binh Thuan- Ninh Thuan: Severe drought is a frequent occurrence due to little rain and high temperature. Wet season is very short while dry season is prolonged over 7- 8 months. River flow is very low in months before the main rainy season. Infiltration of salt water takes place in the coastal areas, especially in Khanh Hoa. In the mountainous and hilly areas, there is erosion and laterization .

b-  Underground water

In Vietnam, the dry season extends for over 6 months resulting in serious shortage of water in many areas. Additionally, extensive deforestation has deprived the land of much of its capacity to recharge the underground aquifers.

Because of water scarcity there is a competition among households, especially for ground water and this is likely to intensify in the coming time. As the demand for water rises, some areas like provinces in Southern Central Coast, Highland Centre, Northern East South and some other regions will face a severe shortage of water.

[Top]

Inland water environment pollution

Pressure

a-  Surface water

Infiltration of salt results from unsuitable exploitation by various sections of water users. For example in Red river, salt infiltration extends to nearly 20 km, while the figure is 40 km for the Thai Binh river.

Municipal wastewater is the main cause of water pollution in the cities and this problem is increasingly becoming worse. Wastewater and rainy water, especially rainy water are not treated.

The problem of water pollution is serious in Hanoi, Ho Chi Minh city, Hai Phong, Da Nang, Hue, Nam Dinh, Hai Duong and other large cities and towns. In Ha Noi, wastewater from living activities and industries is not treated. Ponds and canals often give out bad smell in dry season; rivers and lakes carry a high load of various pollutants. Moreover, as the industrialisation process has increased, industrial waste has also contributed substantially to pollution. In Ho Chi Minh city, water in ponds and canals is more polluted due to rapid growth of population. Sai Gon harbour is one of the major centres for the transportation of oil products and in recent years there have been several incidents of oil spills.

b-  Underground water

Inappropriate exploitation changes the chemical components in ground water, leads to salt infiltration and pollution and underground water can not be exploited.

Salt water infiltration into ground water is very common in the coastal areas in Vietnam like Quang Ninh, Hai Phong, Thai Binh, Thanh Hoa, Vinh, Hue, Da Nang, Nha Trang, Phan Rang, Ho Chi Minh city, Tien Giang, Ben Tre, Ca Mau, Kien Giang, etc. In some other areas, though these are located far from the sea, but due to the existence of ancient aquifers of salt water, the salt water can become integrated with nearby fresh water during the extraction process. Such occurrence is noticed in Hai Duong, Hung Yen, Ha Tay, Bac Giang, Long An, etc.

Water flow is declining in the drilled wells, as is clearly evident in the wells of Hanoi. Some other signals observed from the wells indicate that with inconsiderable changes in exploitation rates, the low level of water increases relatively rapidly and some wells have the water level at 30m [9].

Exploitation of ground water is the cause of soil subsidence, which affects the works and buildings on the surface. In Ha Noi, the result of the initial observation shows soil subsidence in some places due to ground water exploitation. Phap Van recorded the deepest collapse, 17.5 cm from 1988 to 1991 while in some other places it varied from 4 to 70 mm.

[Top]

Status and trend

a-  Water of rivers in the North

The analysis of observation results from the years 1995- 1997- 1998- 1999 compared with that of observation results from 1991 to 1993 reveals that:

-  Red river section located between Lao Cai and Ha Noi: Biological oxygen demand (BOD), Chemical oxygen demand (COD) and some other parameters meet the demand of category A based on Vietnamese Standards TCVN 5942- 1995. Except for parameters like NH₄⁺ and NO₂^- whose values exceed the permitted standards by 1.5-2 times. However, in the riversides near the outlets from the enterprises, such as Bai Bang Pulp and Paper Factory, Lam Thao Super Phosphate Factory, and in Viet Tri industrial zone, the values of some of the above parameters exceed the permitted standards. For example Red river from Dien Hong to the confluence at Viet Tri is severely polluted, especially during the dry season. COD of this river section exceeds 2.37 times, BOD 3.83 times, NO₂^- 1.4 times and NH₄⁺ 2 times, compared with the permitted standards for surface water of category A. In the upstream section of Red river in Lao Cai, the existence of heavy metal and phenol is also observed. Nevertheless, the concentration of these substances is still below the standard of TCVN 5942-1995.

- The Cau River section located in Thai Nguyen city is considerably polluted due to industrial discharges. The section of the river running through  the town has high BOD and COD, low dissolved oxygen, the concentration of H₂S is up to 7.8 to 12mg/l, NO₂^- higher than the standard for water source of category A by 5-10 times, NH₄⁺ higher than the standard for water source of category A by 2 times.

- Thuong river located near Bac Giang bridge: BOD is higher than the standard for supplied water of category A by 2.68 times, COD 1.85 times and NO₂^- concentration is much higher than permitted standard.

- Cam River and Tam Bac River in Hai Phong City: Pollution is considerable. Values of BOD and COD parameters increase gradually from 1995- 1996- 1997 for the two rivers. Construction of embankment in the riversides helps to decrease pollution.

In investigated rivers, analysis of parameters shows that they satisfy the standard of surface water of category A (for potable water supply). If compared with standards for water of category B (for other purposes, not for potable water supply), they all meet the specified standards. NH₄⁺ in some rivers in the North increases from year to year.

b-  Water of rivers in the Central Region

Rivers in the centre are characterised by short length, steep slopes, and frequent flash floods that cause significant damage to lives and property.

- Average values of parameters measured in 1995 of Hieu River in Dong Ha Town are as follows: BOD and COD exceed 2-3 times the standard, NH4⁺, and PO₄^-3 1.5 to 1.8 times, respectively.

- In dry season, BOD, COD, NH₃ of water in the Huong River at Hue City are lower than the standard. However, in some places near the outlet of waste water, like Dong Ba Market, port, confluence of the river, etc BOD exceeds the standard by 2.5 times and COD 1.6 times, respectively.

- In rivers of Da Nang city, DO is nearly equal to category A but BOD is higher than the value for category B. NH₃ exceeds 1.4 to 2.6 times.

- BOD of water in the stream within a radius of 3-5 km exceeds the permissible standard by 1.01 to 1.75 times. Some places in the rivers have oil content of 0.1 mg/l, such as Tuy Loan River, Cau Do river, Phu Loc bridge, and sewer of market in Han River. Nevertheless, it is still lower than the permissible maximum standard (1 mg/l).

Quality of water in rivers In general, quality of water in rivers in the Central zone of Vietnam is relatively good. The upstream  and midstream sections have water quality of category A in comparison with Vietnam Standard TCVN 5942-1995 and are good sources of potable water supply for the people, cities and industries. They are Vinh Phuoc River in Dong Ha, Huong River in Thua Thien- Hue, Tuy Loan River in Da Nang, and Tra Khuc River in Quang Ngai. However, the lower sections of these rivers or rivers receiving wastewater from cities and industrial zones are polluted and they are sources of category B based on Vietnamese Standard TCVN 5942- 1995.

 

[Top]

Water of rivers in the South

Process of water pollution in Dong Nai and Sai Gon rivers:

+ Sai Gon river: BOD and COD at Phu Cuong bridge exceed the permitted standards by 2 to 4 times. Coliform exceeds by up to 50- 100 times. Many rivers have oil and the presence of some heavy metals like Pb, Hg, Cr, and Cd has been detected.

Estimated DO level shows that organic pollution in Sai Gon river is higher than Dong Nai. In Sai Gon river, the most polluted area is from Binh Phuoc to Tan Thuan (DO is less than 1.0 mg/l). Content of nutrition substances like nitrogen, exceeds the standard many times, especially near the Nha Rong Wharf, where the water is always in a state of eutrofication.

+ In Dong Nai river, from Cat Lai to Thien Tan, DO increases from 5.5 to 6.5 mg/l. In some places DO reduces or increases suddenly but is always from 5.5 to 6.5 mg/l. Equivalent total N and P are over 0.2 mg/l and 0.03 mg/l, respectively.

It can be seen that pollution in dry season (April- 1998) is higher than wet season (September 1997).

BOD and COD in all areas of Dong Nai, Sai Gon, and Vam Co Rivers are higher than Vietnam standard for water source of category A.

- Thi Vai river: It can be said that Thi Vai River is a reservoir of industrial waste water of the economic development triangle Ho Chi Minh City- Bien Hoa- Vung Tau.  In Go Dau, BOD and COD exceed the standard by 10- 15 times for the water source of category A, and 2-5 times for the water source of category B. The concentration of nutrition substances like Nitrogenous and Phosphate also exceeds the standard. The content of H₂S of the mud in the bottom of the river is very high in places near the outlet. The content of Chromium changes from 0.02 to 0.035 mg/l. Content of Mercury is less than 0.0002 mg/l, lead is lower than 0.001 mg/l, Arsenic is lower than 0.005 mg/l, which is lower than the standard.

- A notable feature of the declining quality of surface water in rivers in the South is the low pH value. Sai Gon River and Vam Co Dong River are heavily acidified, accordingly the pH are equal to 4.4- 5.0 and 3.8- 4.0 respectively. Figures 4.3 and 4.4 illustrate the change of N-NH₄ and BOD₅ in some rivers within Vietnam based on monitoring results from 1995-1999. The low pH of river water is probably due to alum run-off in the rivers basins.

Changes in N-NH₄ concentration in rivers monitored between 1995-1999

Source : Report of results of Environmental monitoring of Inland stations in the North, Centre and South [1,2,3]

The change of BOD₅ concentration in monitored rivers during 1995-1999

Source : Report on results of Environmental monitoring of Inland stations in the North, Center, and South [1,2,3]

[Top]

Pollution of underground water

- In general, content of BOD₅ and COD of ground water are much lower than the standard. Initial studies of 23 samples (taken in dry season in Hai Phong) indicate that average content of BOD₅ is 2.16 mg/l; Max: 4.74 mg/l and min -0.76 mg/l (3 times lower than the allowed standard). COD often exceeds the standard by twice (max = 45.2 mg/l; in = 2.5 mg/l) and 11.43 mg/l is often found.

- Pollution by nitrogenous compounds: From 1978 up to now, the increase in exploitation of ground water is considerable in Ha Noi. This increase leads to quite low water level (from several meters to nearly 30m and from narrow area to the whole city). For the main watershed Qa in the North delta, degree of pollution of nitrogenous compounds is different.

In Ha Noi, pollution by NH₄⁺ and NO₂^- is clearly evident. One third of the samples have contents exceeding the permitted standard. In Hai Phong, there is pollution of NO₂^-(48% of the samples exceed the allowed standard). In Nam Dinh, 30- 47% of the samples of NH₄⁺ and NO₂^-  exceed the permitted standard.

- Phosphate pollution (PO₄^3-) : Content of PO₄^3- in underground water of Qq (North Delta) in some places has evidence of increasing over time. Average value of many years is from 2.9- 7.9 mg/l, which occupy over 40% of total reference years (1978- 1995). The impacts of water pollution on the environment

The pollution of surface water in urban areas, particularly in Hanoi, Hai Phong, Nam Dinh, Hai Duong, Thai Nguyen and Viet Tri directly affects the water supply for irrigation and aquaculture and results in reduced yields in agricultural and fishery sectors.

Water of Cau river is polluted by wastewater of Hoang Van Thu Pulp and Paper factory in Thai Nguyen city that caused the death of some cattle.

[Top]

Responses to protecting the inland water environment

 

The existing policies.

The following laws, decrees and regulations have so far been issued:

Decree 200/TTg dated April 29, 1994 of Prime Minister on guaranteeing clean water and rural environmental sanitation.

Instruction 487/TTg dated July 30, 1996 of Prime Minister on strengthening the State Management for water resources.

Law of Water Resource approved by the National Assembly in May, 1998 and it came into force from June 1, 1999.

Decree on guiding the implementation of the Law of Water Resource and regulating the punishment of administrative violation in the water resource field.

National Council of Water Resource established by the decision N^o 67/2000/QD-TTg, June 15, 2000.

Vietnam Mekong River Commission was established in April, 1995

The strategic orientations for protecting water environment are as follows:

Strategic Orientation of Urban Water Supply up to 2020, Ministry of Construction (MOC), 1998

Strategic Orientation of Urban Development up to 2020, MOC, 1999

Decision No 237/1998-QD-TTg dated December 12, 1998 on approving the National Target Programme of Clean Water and Rural Environmental Sanitation

Decision No 104/2000-QD-TTg dated August 25, 2000 on approving the National Strategy for Clean Water Supply and Rural Environmental Sanitation up to 2020.

Policy successes and failures of water environment management

Although the law and decree system was set up and approved as mentioned above, the environmental management and protection instruments in general, and water environment in particular are still weak and there are several shortcomings. This led to the inefficiency of water environment management and the inoperativeness of environmental protection instruments. One of the main reasons is that the state management system and apparatus for environmental protection from the central to local levels have not been able to meet the requirements and have the following limitations:

Water environment management activities and system to collect environmental taxes, drainage fee, water pollution fee, etc. are not looked upon as national economic activities, rather as measures to reduce violations of environmental laws and regulations. Budget for investing water environment protection and management work is still far from the demand.

The lack of  strategies on managing and protecting water environment that are suitable to the process of national and regional economic development.

The regulations of water environmental protection and management are not systematically developed and insufficient.

At all levels, local and central state organisations for water environment management and protection are overloaded with work and unable to implement the heavy day-to-day tasks due to lack of manpower and finance.

Other tools for water environment management and protection such as standards of water quality are not clear, not comparable to international standards or suitable to local conditions of all regions.

The regulations of financial contribution for water environment protection and management have not been issued yet, which causes financial insufficiency and the revenues do not cover expenditure.

Insufficient financial contribution and income sources lead to lack of technical capability at the units and environmental protection organisations. Wastewater treatment technologies are weak and backward, contributing significantly to water environment pollution.

Public awareness and community education programs on environmental protection in general and water environment in particular are insufficient  or given inadequate attention. Thus this led to violations of the Law and water environment pollution.

Appropriate policies and strategies for sustainable water management

To improve the water resources management and planning capacity. To set up strategy, plan of exploitation, utilisation and water resources protection in accordance with the river basin and territories. To strengthen the state management for water environment protection from central to local levels. To develop comprehensive policies for socio-economic development linked to water resource and environmental protection. To set up policies of rational exploitation, utilisation and economisation of water resources.

In order for the environmental standards to be realised in practice, the responsibility of water environmental polluters should be determined in relation to such other related factors as technological development level, pollution load carrying capacity of water bodies etc. Based on these issues the standards for effluent discharge should be developed for controlling water environmental pollution.

To promulgate regulations of product quality corresponding to environmental standards during life cycle of products.

To develop policies for encouraging the application of cleaner production technologies, wastewater treatment advanced technologies and preventing polluting technologies. To set up preferential policies to tax reduction and exemption for enterprises that import and apply cleaner production technologies, improve or renew technologies for the control of pollution of water environment, etc.

To strengthen water service organisations in the provinces (irrigation management) and public service agencies in the cities or urban areas (water supply, sewerage and environmental sanitation).

To promulgate economic instruments according to the “polluter pays principle”, “users of water should pay for water”. Water should be considered as an economic good. To develop policies for collecting fees and levies, penalties and to enhance the inspection and control for the polluting enterprises.

Improving quality of collection and preserving data on quality and quantity of water sources. Developing database for assessing potential of ground water by basins, establishing relationship between surface water and ground water.

Continuing to strengthen public awareness, education, training in the field of water environment protection and management, including water pollution control.

For implementing strategies and policies effectively, it is necessary to co-ordinate the tasks among the State institutions from Central to local levels: Ministry of Science, Technology and Environment (MOSTE), Ministry of Agricultural and Rural Development (MARD), Ministry of Industry (MOI), Ministry of Planning and Investment (MPI), Ministry of Education and Training (MOET), etc together with DOSTE at provincial levels. It is also necessary to co-operate with the enterprises, companies and community in this effort.