Out Flow To Sea: Environmental Effects

A lot of publicity is being made that a huge quantity of about 36MAF is flowing to the sea on the average which should be utilized by building new storages like Kalabagh Dam. In this context it may be stated that the water presently going in to the sea also includes, un-utilized part of existing allocations/ commitments under the Water Accord (12 MAF), flow from eastern rivers allocated to India for its exclusive use (8.7 MAF) and un-utilized portion of India's entitlement on western river (4.8 MAF). Besides 10 MAF have been provisionally earmarked in the Water Accord, 1991, for out flow to sea. After accounting for these commitments, there is no surplus water for construction of Kalabagh Dam.

The quantity of out flow to sea has been progressively reducing, particularly after the construction of more barrages, dams and link canals after the signing of Indus Water Treaty, 1960. The actual out flow to sea at the time of independence was about 80 MAF, which has now reduced to 36 MAF. The duration of the flow has also reduced to less than 2 months and that also only in high flood years. Even this quantity is dwindling further as the un-utilized allocations of water are being harnessed.

Under the provisions of the Water Accord, 1991 a quantity of 10MAF has been provisionally earmarked for outflow to sea pending further studies to be undertaken to establish the needs of minimum escapages down stream Kotri. Unfortunately the study has not been initiated even after 7 years of signing the Water Accord due to frivolous objections raised on the terms of study. However, the IUCN, an international organization based in Pakistan has worked out the annual requirements for out flow to sea for environmental sustenance to be 27 MAF. This corresponds to 0.3 million cusecs discharge flowing for a period of 45 days. Let aside the requirement of 27 MAF indicated by IUCN, the quantity of even 10MAF provisionally allocated under the Water Accord is available only for 24 out of 72 years as calculated under the title `Kharif availability'. It is therefore abundantly clear that the required quantity of water for the sustenance of the environment cannot become available under the present circumstances when water is already committed for existing uses and storages. It is not possible that this position can be improved by denying the allocations/ commitments of present operational projects or by leaving the existing storages unfilled. However, it is important that at least further deterioration in the ecological conditions must be prevented. The best that can be done to save the environment from complete devastation is to plan future projects so that the minimum required discharge of 300,000 cusecs is available for outflow to sea at least for as much time as it is available, after meeting the current Kharif demand. This figure of 0.3 million cusecs is also supported in the WAPDA's exercise of 1992. The balance flood water over and above this requirement could be impounded in future storages, which can only be possible in the form of carry over dams.

Colossal damage has already been caused to the environment in lower regions, as under:-

1. Progressive reduction in the volume of silt from 200 million tons/ year in 1947 to 36 million tons per year in 1991. This has resulted in the erosion and degradation of the Delta and consequent sea water intrusion besides the harmful effects on fisheries, specially shrimp and mangrove forests due to loss of nutrients.
2. The mangrove forest area has reduced from 263,000 hectares in 1977 to 158,500 hectares in 1990 showing reduction of 38%. Even this remaining area is being progressively degraded.
3. The famous Palla fish has become nearly extinct. The annual production has reduced from 5000 tons in 1951 to just 500 tons, besides marked reduction in its size. The rare species of fresh water Dolphin are also facing similar threat.
4. 600,000 acres of riverian forests and 550,000 acres of sailaba areas of Sindh have been very seriously affected and they are in the danger of complete elimination.

Pakistan is signatory of Rio Declaration signed by the Prime Minister Mian Muhammad Nawaz Sharif. The Principle No. 4 of this declaration proclaims that ``In order to achieve sustainable development, environmental protection shall constitute an integral part of the development process and cannot be considered in isolation from it.'' We should therefore, do all that is possible to abide by this commitment in letter and spirit.