KARACHI (PPI) - The Indus River system is under the influence of massive water divergence, climate changes and increasing seawater intrusion on the Indus Delta, which is currently facing acute water shortage, says a research report conducted by an environmental expert Dr Altaf A Abro. Rivers and aquifer systems need water to maintain themselves and their functions and the services they provide to the society. Minimum flow requirements are needed to maintain the Indus delta ecosystem functioning and the associated livelihoods. Environmental flows provide critical contribution to river health, economic development and poverty alleviation but in Pakistan, the environmental flows concept is still in its infancy. Like in many other developing countries, water planners and managers in Pakistan consider water flowing to the sea as 'wasted. Since the creation of Pakistan , government followed approach based on the supply side of economics to harness river waters through dams and other structures to cater to the growing demand of irrigated agriculture for water. The emphasis was more on making water available through developing new resources rather than efficiency and conservation. Even the National Water Policy of 2003, which is yet to be approved by the cabinet, does not deal with the institutional mechanism to make water allocations for the environment. Considering the fact that downstream of Kotri barrage, millions of people (in districts; Karachi , Hyderabad , Thatta and Badin) depend on the river for drinking & other domestic uses, agriculture, forests, and aquaculture. The Thatta district alone has a population of over 1.1 million, as well as 250, 000 cattle heads, and a forest spread over 425,000 hectares. The river water flowing downstream of Kotri Barrage to the sea has the vitality to sustain the life of Indus delta which is a vast region with more than a million human population alone in the deltaic region, many millions of livestock, the seventh biggest mangrove forest of the world flourishing in it, about 150 islands with great potential of tourism, and fish product worth billions of rupees per annum. The popular sentiment among the people of downstream Kotri is that the Indus Water Treaty (1960) that occurred during the Post-Kotri period has significantly affected environmental flows downstream. Although, irrigation developments occurred throughout the Indus River basin during Pre-Kotri period, but their effect on the riverine areas was not that significant. The commencement of Tarbela Dam with a large storage capacity on the Indus River coupled with further irrigation abstractions in the basin resulted in a significant reduction in the freshwater releases below Kotri. Under the natural flow conditions (without upstream abstraction of water for storage and irrigation) during the Pre-Kotri period, the maximum extent of the seawater intrusion reached 100 km upstream from the river mouth about two percent of the time. When the natural flow was reduced due to upstream uses, the degree, extent and frequency of seawater intrusion was drastically increased resulting in adverse impacts on the areas downstream of Kotri Barrage. The 1991 Water Accord identified the problem caused by reduced freshwater flows and recognized the need for studies to estimate the minimum outfall below Kotri Barrage to check seawater intrusion. Nonetheless, no effort was made to estimate the minimum flows required for downstream Kotri. For past two decades WWF-Pakistan and other civil society institutions, NGOs, and the individuals kept hammering on the issue, eventually momentum built up, and the Federal Flood Commission (FFC) that works under the Ministry of Environment (MoE) paid attention to the matter. Nevertheless, FFC wasted almost ten years in squabbling over the Terms of Reference of three studies to estimate the environmental flows required for the Indus delta. Studies identified three distinct periods in which irrigation developments occurred in the Indus River basin . These three periods are - Pre-Kotri (1937 to 1954), Post-Kotri (1955 to 1975 and Post-Tarbela (1976 to 2004). The study I (Water Escapages Below Kotri Barrage) analyzed the data of 10-day releases below Kotri for the period from water year 1955 to 1975. However, based on the previous works on the quantum of water required to save the delta, its environment and peoples livelihood, now experts are of the opinion that a minimum flow in rivers is better than no flow.