INTRODUCTION

A cluster of ancient temples known as Katas Raj is located in the Choa Saiden Shah (Study Area), a town of the Salt Range, Punjab, Pakistan. The Katas Raj Temples antedate the birth of Jesus by hundreds of years (Ali, 2015). Scientist Alberuni attempted to measure the circumference of the earth at the place of Katas Raj (Shahab, 2019). The Katas Raj complex is a sanctified place in the Hindu religion especially the sacred pond that has different myths regarding its formation. Hindus believe that all the sins are washed out after taking a bath in the pond. According to the book of Rig Veda, a small stream having a depth of 300 yards exists just beneath the pond (Shahab, 2019). Apparently, the pond is filled naturally from the series of springs and artesian aquifer since its creation. The pond occupies an area of 14960 sq. ft., with a maximum depth of 20 feet. Until 2007, there was no shortage of water in the pond but after industry development and agriculture growth, its water level started declining, ultimately drying-up in 2017. The agriculture sector is the major user of groundwater in the study area beside the domestic water supply. The cement industry also prefers to use groundwater for the cooling process due to its local availability and acceptable quality.
The concern of the Hindu community is that the Government of Pakistan does not take care of the pond (Ali, 2015). No doubt the Government of Punjab took initiatives in the renovation of the temples but unfortunately no concrete steps were taken to preserve the pond due to lack of knowledge about its groundwater system. The groundwater levels are expected to face even worse conditions because the cement industry is going to further expand in the Salt Range to meet the increasing demand for cement due to China Pakistan Economic Corridor (CPEC) projects and future economic development of the country. Given the extent of groundwater resource depletion during the last 10 years, water management is necessary to ensure the sustainable use of water in the Salt Range which needs a comprehensive hydrogeological/hydrometric study. (National Engineering Services of Pakistan, “Delineating Negative and Positive Mining Areas for the Installation of Cement Plants in the Salt Range”,unpublished report, 2018). In past, no appreciable studies were carried out for groundwater analysis of the study area to suggest measures to mitigate the effect of climate change and industrial stress. However, recently, a study was carried out to assess the impact of water abstraction on the aquifer of the Kahoon Valley, Choa Saiden Shah based on limited geological and hydrological data without creating any groundwater flow model. This study concluded that the water table has declined by 4.8 m on average in the whole valley in 08 years between 2004 and 2012 proposing numerical computer modelling to opt optimal method for artificial recharge of the aquifer of the Kahoon Valley for sustainable water resource development (Dr. A.D Khan, Oriental Engineering Services, Lahore, Pakistan, “Impact Assessment of Groundwater Pumping on Kahoon Valley Aquifer” , unpublished report, 2012).
Already Pakistan uses groundwater resources to the maximum limits of withdrawal causing significant drawdown of the water table in different parts of the country (Young et al., 2019). For instance, the Rachna Doab, command area of Lower Chenab Canal (LCC) in west Punjab Province is currently threatened due to the significant drawdown of the water table which would reach a maximum of 14 m till 2030 based on current abstraction against the existing recharge rate, recommending sustainable water management (Shakoor et al., 2018). Similarly, the water table in Mithawan spate irrigated area of D.G. Khan, Pakistan is expected to deplete up to 2.85 m / 10 years in the period from 2014 to 2024 based on current abstraction which may be stopped by maximum use of spate water/ hill torrent for irrigation and reduce the reliance on groundwater (Ahmad, Arshad, Iqbal, Waqas, & Awais, 2017).
Groundwater abstraction is 33% of total water withdrawals worldwide, consequently, most of the aquifers in arid and semi-arid zones that rely on groundwater are experiencing rapid drawdown of groundwater (Famiglietti, 2014). The global groundwater depletion has increased from 126 to 283 km3 within 40 years from 1960 to 2000 in sub-humid to arid zone(Wada et al., 2010). This depletion rate has increased significantly since 1950, with a maximum average rate of 145 Km3/year which is equivalent to a 0.40 mm/year rise in see-level during the period 2001-2008 (Konikow, 2011).
A few other archaeological/sacred places are also facing a similar issue as that of Katas Raj sacred pond. The water tanks/ponds of Mylapore and Thirupporur temples located in the city of Madras, India had dried out in the past decade due to rapid urbanization and continuous groundwater abstraction. Due to urbanization 90% area around the temple tanks has become paved causing no recharge to the aquifer, therefore, these tanks can only be fed artificially by rainwater harvesting through storm drains covering all the catchment areas which originally contributed to recharging the tanks (Ganesan, 2008). The artificial recharge of an aquifer is termed as Managed Aquifer Recharge (MAR). A variety of methods are used for MAR such as streambed channel modifications, infiltration galleries, recharge wells, and runoff harvesting (Dillon et al., 2019). The runoff harvesting is an efficient method for aquifer recharge in arid areas and cost-effective as compared to other methods of MAR (Hashemi, Berndtsson, & Persson, 2015). MAR describes the global recharge of the aquifer for environmental protection and the quality of groundwater (Sheng & Zhao, 2015). MAR is an important water management strategy to balance the water-stressed groundwater system. The other purpose of MAR is to overcome the seawater intrusion and land subsidence (Bouwer, 2002). MAR requires permeable soils for surface infiltration and in the case of impermeable soils, the aquifer is recharged through vertical injection by digging trenches or wells in the vadose zone (Bouwer, 2002). The researchers emphasize MAR methods for sustainable water management keeping in view the future demand for water, global warming, and climate change.
Sustainable groundwater development needs to be exercised for the recovery of the environment and groundwater quality. Therefore, the current study is an effort to analyse the groundwater regime of the study area under different development scenarios besides the application of the MAR approach using state of the art groundwater modelling techniques to select a suitable strategy for sustainable groundwater management to protect the sacred pond.

Description of the Study Area

Salt Range, the mining hub in Punjab, Pakistan, is a series of hills having length of 250 km and is 10 km wide. The range contains deposits of salt & coal. Cement factories are the main industrial sector in this area having large production of Portland cement. The study area is a small valley that lies between 32°40’0”N latitude and 72°42’0”E longitude spread in 175 km2 in the Salt Range. The ancient Katas Raj Temples are located in the northern part of the Salt Range in the Potohar Plateau region of Province Punjab, at latitude 32°43’26.47”N and longitude 72°57’5.96”E as shown in Figure.1 .
The topography of the area plays an important role in the groundwater flow pattern. Generally, the groundwater follows surface topography flowing from a higher elevation recharge zone to a lower elevation discharge zone. The Digital Elevation Model (DEM 30 m SRTM) of the study area was downloaded from U.S Geological Survey (USGS) Earth Explorer Portal as shown in Figure.2 . The surface elevation varies between 598 m to 979 m above Mean Sea Level (MSL).