Basin Rights of International Rivers

International River Law Network - Dr. Wang Zhijian

Past Postdoc and Visiting Scholar Associate Professor of International Law at Hohai University, Dr. Wang Zhijian, researches international rivers, environmental protections, and basin development. He has developed a model for estimating the basin rights of international rivers to aid in determining appropriate allocations between basin states.

Basin Rights of International Rivers

The principle of equitable and reasonable utilization is widely accepted as a rule of international water law; however, it still has ambiguity.  Equitable, in the context of international river law, is expressed through the reciprocity of rights and obligations of basin countries. Countries share in the right to utilize a river. At the same time, there is an implication of a corresponding obligation to protect the river. Through this lens, the term reasonable may be defined as a sustainable use of a river - implying the river, and all its inhabitants, have the right to live. From the environmentalist perspective, we term this as the ‘rights of nature’. In addition to the rights of nature, the equitable and reasonable use principle applies, also applies to two additional ‘rights’ – human rights for individual water needs and water rights for basin countries.  These three should combine to yield the total ‘basin rights’ available in a river system.

We developed a model to estimate the quota of water resources for each of the three factors, so that they could be used as a tool to aid in negotiations on water allocation. We propose our basin rights model to have three parts: nature rights for the river’s ecosystem; human rights for the basin population, and water rights for each basin country. The three factors are explained in more detail below. This model provides a starting point or basic platform for facilitating different needs for stakeholders.

The model uses this formula:

B=N+H+W; where

B= Basin rights;

N=Nature rights of river for the basin

H=Human rights of individual water needs for the basin

W=Water rights for all the basin states.

Then, in order to calculate N, H and W, we assume that:

B=Whole discharge of the basin;

∆x = Country x's flow contribution rate;

Hx = individual country X’s human right to water

P=the amount of the basin population; then:

N=B∗10% (arid basin);  Or, N=B*20% (semi-arid basin);  Or, N=B*30(humid basin)

Accordingly, human rights to water can be calculated by the following formula:

H=P∗1000 m3/cap/yr (arid basin);

Or, H=P*1300 m3/cap/yr (semi-arid basin);

Or, H=P*1700 m3/cap/yr (humid basin);

The whole basin rights can be seen as the discharge of all of the basin water, so the whole water rights for all the basin states can be calculated as:

W=B-N-H(whole basin)

To calculate the Water Quota for each Basin Country,

Since the beginning of an international river negotiation could be to calculate the water rights quota for each basin state, not the whole basin So, for each basin, state X’s water quota can be calculated by:


Without taking into account the seasonal variability of water for each individual river, the water quota calculated using this formula could be used as an initial platform for international water negotiation. This is a highly flexible structure, as the frequency (monthly, seasonally, annually) and location of discharge measurements can be determined by the negotiating parties.

Nature Rights (N)

To consider a river’s natural character, one must consider geographic, hydrographic, hydrological, climatic, ecological, and other factors together. In order to quantify it, we propose that the ecological water requirement is calculated based on requirements of the natural system, and that the calculation should consider the individual climatic region.
We adopted the Tennant method to quantify nature rights. The method shows that 30% of average flow or higher is considered to be in the good to optimum range for aquatic organisms, 10% of the average flow is a minimum instantaneous flow recommended to sustain short-term survival habitat for most aquatic life forms, and 20% of the average flow is recommended as a base flow to sustain fair survival conditions for the ecosystem. Which yields the models’ nature right as:

N=B∗10% (arid basin); Or, N=B*20% (semi-arid basin); Or, N=B*30(humid basin)

Human Rights (H)

The human right to water consists of the requirements of vital human needs, including water for drinking, sanitation, and food production. To meet the sustainable threshold, in 1994, the FAO recommended that roughly 1,000 m3 to 1,300 m3 should be reserved for meeting the individual annual food based water requirement (FAO, 1994). Furthermore, using the concept of “water scarcity” based on per capita usage, the water conditions in an area can be categorized as: no stress (>1,700 m3), stress (1,000-1,700 m3), scarcity (500-1,000 m3), and absolute scarcity (<500 m3) (UNDP, 2006). For the majority of international river basins, we can use 1,000m3; 1,300m3; and 1,700m3 as the key threshold values for arid, semi-arid, and humid basins, respectively. Accordingly, the models’ human rights to water can be calculated by the following formula:

Where P=the total basin population;

Then: H=P∗1000 m3/cap/yr (arid basin); Or, H=P*1300 m3/cap/yr (semi-arid basin); Or, H=P*1700 m3/cap/yr (humid basin);

Water Rights (W)

The whole basin rights are estimated to be the discharge of the river system; therefore, the whole water rights for all the basin countries can be calculated as:



The basin rights approach might provide an alternative idea and methodology for establishing a starting point for international river negotiations. The approach takes into account both history and hydrology by reserving human water rights in advance. Additionally, the inclusion of an ecological water requirement as a prerequisite for sustainable use divides the responsibility among all the basin states. This consideration can help to balance the rights and obligations between nature and humankind as well as between upstream and downstream users. If the negotiating parties share several types of basic data such as discharge, runoff contribution, and population, it would be very easy for them to figure out each country’s water quota and make decisions on whether building massive infrastructure in one basin state would exceed its water quota. The water rights, nature rights, and human rights for 276 international river basins, using an older TFDD delineation of basin boundaries, has been calculated an is available on the International River Law Network Website.