I t is an age-old problem that has plagued efforts to manage the Mekong River since

the late 1950s: while all members of society need access to water, some countries

by virtue of their location on the river system - or by using political and economic

power - are in a position to control water flow and get a disproportionate amount

for themselves.

The latest attempt to solve this - though critics say will worsen it - is a proposal

for the construction of 11 "run-of-river" designed dams on the mainstream,

between Pak Beng in north-west Laos and Phnom Penh, among some seventy Mekong River

Commission projects involving the diversion of water from the Mekong.

The plan has unleashed a storm of criticism from environmentalists and concerns in

Cambodia that the dams may adversely impact the country's Tonle Sap lake and fisheries,

agriculture and people which rely on it.

The run-of-river dams supercede the former Mekong Committee's "cascade plan"

created by the US Bureau of Reclamation in the 1950s: a succession of large-scale

reservoir dams along the mainstream of the river.

The new proposal is being sold as a way of bringing about the long-held goal of harnessing

the river's mainstream for energy generation, while minimising harmful social and

ecological affects, especially relocation.

The projects under consideration are smaller in size and power, a total of 15,000

megawatts, compared to the old plan which would have generated 19,000 megawatts.

The idea was among many discussed in early April, when the governments of Thailand,

Vietnam, Laos and Cambodia met in Chiang Rai for the inauguration of the Mekong Committee's

latest incarnation, the Mekong Commission.

They also signed the agreement on the Cooperation for Sustainable Development of

the Mekong River Basin.

Support for the plan among the governments of Indochina is based upon the possibility

of massive revenue earnings from the river and a desire to get a slice of donor money

presently being made available for Mekong-related research and development.

It has also received important backing from a number of important groups.

Foremost among these is the Thai government, which is forecasting a tripling in its

demand for electricity by the year 2005, but is running out of dam sites and coming

under increasing public opposition to further dam construction. It needs to woo neighbouring

countries to cooperate in the harnessing of the river and its tributaries for power

generation.

Thailand needs - according to one of the Committee's own reports - 88 percent of

the energy generated from the Lower Basin developments, but 84 percent of the power

potential lies in Laos and Cambodia.

The Director of Thailand's Department of Energy Promotion, a long time proponent

of the scheme, was one of the main negotiators of the new Mekong accord.

For major donors like the Asian Development Bank (ADB), electricity generation from

the Mekong is a vital part of plans to link the economies of Indochina, Burma, Thailand

and southern China into a regional market of 220 million people.

Numerous donors from countries such as Australia and Japan and especially the United

Nations Development Programme (UNDP) are providing money.

Despite repeated denials to the contrary, UNDP in particular, has played a vital

behind the scenes role in laying the legal, financial and administrative foundation

for mainstream dam building, and a key facilitator in the process leading to the

establishment of the Mekong Commission.

Its role has become even more important of late: for example, a UNDP expert sits

on the Commission's key Joint Committee planning group.

Opposition to the run-of-river scheme has focused on two areas: water flow and fisheries.

A tropical monsoon river system, every year the river spills its banks and spreads

over tens of thousands of square kilometres in Laos, Cambodia and Vietnam, replenishing

essential nutrients in soil and providing spawning grounds for fish.

Environmentalists claim this seasonal flooding is the single most important factor

linked to the productivity and diversity of agriculture and fisheries in the Mekong

basin.

A donor official in Vientiane dismissed talk of downstream impacts as a "beat

up".

"You are not taking water away from the river, [the projects] just change the

flow.

"Indeed, you have a chance to store water for the dry season to lesson the impact

of floods such as those often experienced in the delta," he said.

However, said a local environmentalist: "The current plan proposed by the Mekong

Secretariat for eleven run-of-river dams on the Mekong mainstream are not designed

to control flooding.

"Any dams built on the mainstream will disrupt the Mekong's natural flow, which

local communities' food security - fisheries and farming - depend upon, both in the

delta and elsewhere."

Such environmental groups have argued the plan could also have dire consequences

for fisheries.

In terms of fish bio-diversity, the Mekong is the second most important river in

the world after the Amazon.

Research commissioned by the Lao government suggests that there are between 400 to

1,000 varieties of fish in the Mekong, the most important species of which are migratory.

A 1987 survey by the Fishery Department of the Ministry of Agriculture, Forestry

and Fisheries in Phnom Penh, found over 200 species of freshwater fish in the Cambodian

section of the river alone.

According to a 1992 Mekong Committee estimate, fish is the main source of protein

for 80 percent of the 50 million people in the lower Mekong basin.

A further 12 million of these people earn a living as full-time fishers, and many

more by processing fish and aquatic products and in related areas.

A number of studies in Cambodia and Laos have revealed that over the last decade

the numbers of fish has gone down due to the increased volume of fishing, technological

improvements and deforestation.

Environmentalists maintain that dam construction has the potential to further reduce

this by disrupting fish migration, and damaging the riverine habitat and food chain

of many fish species, possibly driving some into extinction.

These concerns have been recognised in the past by the Mekong Committee itself.

A 1992 report by the Committee said that given the possible impacts "and the

undoubted importance of the Great Lake-Tonle Sap and flood plain fisheries to the

livelihood of the rural Cambodian people, projects impacting on flood plain hydrology

should receive careful attention with respect to potential fisheries impacts."

The dangers were also recognised by the Cambodian government in its first State of

the Environment Report in 1994, which stated that the proposed hydro-power and water

control projects on the mainstream and tributaries of the Mekong will "change

the hydrological regime of the Mekong River resulting in diminished flows at certain

critical times"

"The change doesn't have to be huge," said one local critic.

"If the water level during the flood season were to drop by one meter, this

would lead to a reduction of nearly 2,000 square kilometers of flooded area around

the lake, which would be a disaster."

Connected to this are fears that there is little difference between the Mekong Committee's

much-criticised old cascade plan for mainstream hydro-energy development and the

run-of-river approach.

The old plan was based in the engineering concept of building storage reservoirs

in the same river basin in a cascade form.

Although the new scheme involves a number of smaller dams along the lower Mekong

Basin to utilise the river's flow, environmentalists are worried it could still have

an impact on fish ecology, and consequently entire subsistence communities.

While the new plan does not require the construction of reservoirs, the dams will

still necessitate the flooding of an estimated 1,900 square kilometers of land, much

of it pristine forest, and displace around 60,000 people.

These concerns were raised by Thai NGOs present at the signing ceremony for the new

Mekong agreement, who urged greater emphasis be given to environmental impact studies

and the cancellation of the run-of-river scheme until it can be proven they are not

harmful to the environment and fish bio-diversity.

Informed sources within the Cambodian government have criticised what they said were

negligible attempts so far to provide information on the plan.