Ali Jabir
The unique patch of daunting mountains in the Salt Range of Pothohar region of Pakistan, the Soon Valley has become a center of attraction for researchers and news seekers to unearth different most modern scientific and nature based solutions adopted to preserve rainwater and treat wastewater that are helpful to address water security issues faced by the country.
The cup-shaped valley is famous for mining of silica sand, crush and coal for the past many decades. Soon Valley homes a wetland complex based on different lakes of Khabheki, Jhalar and Uchali that are part of Ramsar Convention and collectively known as Uchali Complex.
Interestingly, the area temperature of the Valley is 3-4°C less than that of the federal capital and makes it ideal for off season crops cultivation like cauliflower, potatoes and green chillies.
The Institute of Urbanism organised an exposure visit for journalists to unearth the various modern strategies adopted by the Worldwide Fund for Nature (WWF-Pakistan) to cope with growing water demand and shortage spiking up side by side.
Khabheki Lake, a saltwater reservoir on average receives 2,200 millimeters (mm) rainfall a year. It is a bowl like structure surrounded by mighty mountains sprawling across the lake.
The WWF-Pakistan had established it’s office at the lake to monitor and guide actions to ensure protection and preservation of natural reserve and explore more areas to improve groundwater storage and availability.
The rooftop of the WWF-Pakistan office at Khabheki Lake has been especially prepared for birdwatching.
Umar Bin Khalid, environmental expert at WWF-Pakistan Khabheki Lake office said the purpose of focussing Soon Valley in practicing wastewater or graywater treatment intiatives was it’s cultivatable land potential. Due to the off-season cultivation, the local farmers are eagerly pursuing vegetables cultivation that had increased the agriculture-based water demands.
However, as a result the groundwater had plummeted below 400-feet due to excessive water drilling in the area.
The WWF is working on freshwater replenishment and preservation efforts in the Soon Valley. It has started installing rainwater harvesting system at the household level particularly in the areas lacking any water supply as it is a low-cost solution and its cost varies due to the size of a house.
It comprises of water tanks storing the filtered water of recharge structures collected from catchment point through conveyance system, filter and recharge structures.
“A rainwater harvesting infrastructure on average conserves 60/m3 through the system installed at the rooftop of a five Marla house.”
At the initial stage, Khalid said some 16 units have been installed whereas the target has been to take the number to 40.
Among few interesting facts about Khabekhi Lake, DrEjaz Ahmed shared that the white headed duck that used to arrive at the Lake in large flocks from Siberia during winters declined drastically as the Punjab Fisheries Department introduced Tilapia fish in the Lake to turn it into a multi-purpose ecotourism site. But the Tilapia’s omnivorous nature put a dent on it as it used to bite the pads of the white headed ducks which caused a decline in its arrival.
The WWF-Pakistan officials also led the journalists to visit Ablution Water Reuse System.
The system has been designed keeping in view the fact that ablution water quality is better than the wastewater and could be easily reused after treatment.
Ablution Water Reuse System is designed primarily for mosques so that the treated water can be utilised for irrigation, horticulture, lawn washing and for making up with non-portable water needs that will help put off huge pressure on groundwater reserves.
The treatment plant consists of three chambers comprising of a settler, filter tank and a storage take. It has a total capacity of 12/m3 of water treatment a day. As per the estimates, on an average some 2.5/m3 treated ablution water is reused in a mosque having around 500 worshippers per day.
Since the ablution water contains less biological and other chemical pollutants, the settler collects ablution water to allow heavy solids to settle to its bottom, the sand and gravel in filter tank remove smaller particles and decontaminates the water and then the treated water is stored in the storage tank to be used for irrigation and cleaning purposes.
This system has been beneficial in many ways as it helps preserve water resources by mitigating wastage, prevents untreated water discharge and reduce environmental pollution, promote hygiene and sanitation.
The third initiative has been of a unique and very scientific nature called Floating Treatment Wetland (FTW) that was installed in Mardwal Village a few kilometers away from the Khabekhi Lake.
A 1.8 acre pond polluted with household wastewater was releasing a strange stink of the algae grown on the accumulated water.
The FTW is a floating platform loaded with plantation that floats on the surface a polluted and degraded water body to purify it from pollutants with the help of plants roots that feed on the wastewater.
It is composed of a mat or raft of buoyant materials like foam to plant seeds whereas the plants’ roots grow deep and extend beyond 5 feet in water.
There were two FTW mats placed at the Mardwal Village pond and were 5-6 inches think and 5’×6’ in size.
Khalid told the media that the plant roots help reduce algae and clean water as it takes on nutrients, pollutants and other contaminants.
According to the WWF-Pakistan, on average 19000/m3 per year of wastewater is estimated to be treated through a FTW installed in a wastewater pond with the size of an acre and depth of one meter with an average daily wastewater flows of approximately 50-70 gallons per person per day.
The pond interestingly had 2-3 feet long fish and turtles that were obscure due to overwhelming algae in the pond water that was mainly sewage, rainwater and household wastewater.
The last site was of ground recharge wells installed in Noushera that lies in the vicinity of the Uchali Complex.
Senior WWF-Pakistan official, Malik Waseem and Usman Bin Khalid jointly briefed the journalists on site.
The officials informed that the groundwater table had declined below 140 feet whereas the sites for recharging the groundwater were selected after hydrological GIS mapping.
There have been four recharge wells planned to be established at the selected sites out of which two have been constructed and as many are underway.
The project has been initiated in July 2022 in Noushera.
The recharge wells consists of 7-8 feet deep pits filled with gravel, sand and stones that act as a filter to purify water. The recharge wells alone at a single site helped collect 8.5 square kilometers rainwater.
The four recharge wells had the capacity to replenish 19000/m3 annually whereas a three-year target of 308 million liter of water per year has been set to be achieved by establishing the groundwater recharging wells.
