It's time to rethink water and energy links in Middle East

Lebanon, a water-rich country by MENA standards.

Much of Lebanon's water comes from snow that falls on its mountains and then melts gradually, yet that snowfall could decline sharply: by 40% with 2°C of warming, and 70% with 4°C, according to the country's Second National Communication to the United Nations Framework Convention on Climate Change.

Because Lebanon is narrow, water also quickly runs off from the mountains into the sea. And coastal aquifers are threatened by seawater intrusion from over-pumping and sea level rise.

Lebanon wants to tap its extensive hydropower potential, but building dams - the most common approach - could divert water from irrigation and urban uses, losing significant amounts of water through evaporation from the reservoirs.

Multi-functional reservoirs (e.g. hydropower, plus irrigation, plus recreation) might help to increase water productivity.

Hydropower is also important for Egypt, supplying 13% of the country's power, mostly from the Assuan High Dam.

Climate change could seriously compromise storage and hydropower production; Egypt also wants to increase its energy efficiency by 20% by 2022, which will help - but it's unlikely to suffice given that Egypt's population is growing by 20% every 13 years.

One promising option for Egypt and other MENA countries is solar-powered water pumps, which are both climate- and energy-smart and take advantage of the fact that highest demands for water pumping (for irrigation) coincide with highest solar insolation in summer.

Treating and reusing wastewater and recovering energy from the sludge would also yield significant benefits; Egypt is ahead of the pack in this regard - the Al Gabal Asfar water treatment plant is nearly energy self-sufficient.