Dear Hussein,

the question you are asking is the same that is asked in many parts of the world - and unfortunately there is no simple answer.

In an ideal world both countries (or, in a more general term, both parties involved - the upstream and the downstream water users) would get together and discuss a sustainable water resource management plan (IWRM) that takes all water demands (as well as ecological requirements) into consideration. This is already difficult enough if both parties are neighoring regions within the same countries. Adding the transboundary character to this problem makes this theroretical solution highly unlikey. There are best case examples like the International Commision for the Protection of the Rhine (or the similar commission for the Danube), but those examples are not loated in arid regions, where the pressure on the limited water resources is so much higher. The commission for saving the Aral Sea tries for decades to solve this problem and sinks millions of dollars into this venture, without much results...

So, let's assume that the reduced water availablity will be a given, what are the remaining options?

1. Reduce the overall water demand - by increasing the water use efficiency (water saving technologies, drip irrigation evaporation control, less water demanding crop types, improving the water infrastructure to reduce water losses etc.).

2. Make the most of the available water resources by reusing/recycling the water several times (desalinization, improved waste water treatment, effective grey water management etc.).

A combination of both options will be most successful. Unfortunately, both options require large investments in terms of money (infrastructure, technological know-how and innovation, long-term education) and political agenda (proper implemenatuion of top-down and bottom-up management approaches, shareholder involvement etc.).

It is not an easy way, but it might be the only one - and it can lead to a more sustainable resource management overall (with positive side effects on the ecology, soil fertility and even economic development).

Dear Michael,

Thanks for your reply and for this good information .

Well,

I confirms Michael Groll answer , and based on the facts of climate change and the evaporation caused by it, so the decision is to must regulate the process of supplying the marshes water, which causes the increase of evaporation, which sometimes reaches 3000 mm per year, which means the loss is very high than what is pumped to the marshes because of shallow depth and wide area, on the other hand give up the process of water transfer through open channels and replaced by closed channels. And stressed on treatment needing for sewage and industrial wastewater. As for the sea salt tongue, the right decision is built dam on the section of the Shatt al-Arab before the mouth of the Karon including a floating navigation gate, which would raise the level of Shatt al-Arab to deter the intrusion of salt water from access to the north of the estuary.

Sincerely