Wetland technology could ease Pakistan's water woes

Saleem Shaikh and Sughra Tunio in AlertNet: For farmer Asadullah Kerio, water shortages are a thing of the past. Since 2010, he has been irrigating his land with treated wastewater from a nearby ‘constructed wetland’ in Majeed Keerio village in Shaheed Benazirabad district, some 271 km (168 miles) northeast of Karachi.

...Sugarcane, mango and banana are the major crops in this central district of southern Sindh province. The local climate is sultry and dry, with summer temperatures soaring up to 49 degrees Celsius. But the area under cultivation has shrunk significantly as many farmers have been deprived of irrigation water due to a drop in the Indus River flows that feed the district’s canals.

....Constructed Wetland (CW) is a low-cost, biological wastewater treatment technology designed to mimic processes found in natural wetland ecosystems, according to the United Nations Human Settlements Programme (UN-Habitat), which has provided technological support for the project.

The shallow basin of the wetland is filled with a filter material, usually sand or gravel, and planted with vegetation tolerant of saturated conditions. Domestic wastewater accumulates in a pond that feeds it into the basin through an inlet-outlet system. It then flows over the surface or through the substrate, and is discharged from the basin through the system controlling the amount of wastewater in the wetland. The treated water can be used for most purposes except drinking and cooking.

...According to a study by the Global Change Impact Studies Centre in Islamabad, Pakistan’s agriculture output could fall by nearly 30 percent by 2030 due to a 6 percent decline in rainfall over that period, caused by climate change.

In 2010 and 2011, Pakistan suffered heavy flooding due to intense monsoon rains. But this year, outhern parts of the country are experiencing drought conditions – suggesting that weather patterns are becoming more unpredictable....

Bagrote Valley wheat harvest, shot by Zensky, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license