Inadequate drainage system has caused the failure of irrigation projects throughout the world. Deficient planning and improper execution of a project results in substantial monetary loss. It is a fact that the upstream part of the catchment area changes the environment of downstream flood plain, its entire echo-system and the wildlife.

Rainfall precipitation, seepage, leakage, overtopping and seasonal inundation has put most of the agricultural land under water logging/salinity and alkalinity. The problem has not only affected the culturable commanded area (CCA), but has also polluted the environment, displacing settlements on mass scale, and vanishing the mangroves. Only 68 per cent land of Larkana surface drainage scheme, on an area of 50,560 acres — 41,830 acres of the CCA, 70 per cent or 29,280 acres located under perennial Dadu command canal and 30 per cent or 12,550 acres under seasonal rice command canal — could come under cultivation due to the salinity and flooding on the abandoned land. Table

S.No. Category Area (Acres) %age 1. Total Gross 50560 100 2. Actually Cultivated Area 34687 68.6 3. Abandoned land (due to salinity & flooding) 5881 11.63 4 Orchards 4449 8.8 5. Wet Lands 2906* 5.74 6. Built up 2627 5.20

The wetland area vary during season to season. In heavy rainfall depression spreads out but in droughts these shrink and smaller ones disappear.

Despite implementation of the drainage projects, over 30 per cent of the gross command area is moderately waterlogged, and more than 14 per cent highly. The purpose of drainage is to displace the excess water and salts from the agricultural land. Many projects were undertaken but high operation and maintenance cost, and failure in remodelling the water courses resulted in the pumpage of poor quality of ground water. This also raised the secondary salinity along with polluting the entire tail of the system.

There exist environmental concerns, besides the impact of saline drainage effluent on wetlands, over the disposal of saline effluent into the evaporation ponds, river or canal system. The evaporation ponds located in the Salinity Control and Reclamation Projects launched in 1950 are posing serious hazards to the adjacent area. The environmental degradation is increasing despite measures.

The second one, Left Bank Outfall Drain (LBOD) was commenced in 1986 in Nawabshah, Sanghar and Tharparkar to lower and control the ground water level, and improve the collection and disposal of saline drainage effluent on about 1.28 million acres, but the project could not achieve it’s intended task. Lastly, the Right Bank Outfall Drain (RBOD), in collaboration with the World Bank and under the monitoring of the NDP has been launched to drain out the sodic/highly saline water from the land lying on the right bank of the Indus basin, thereby aiming to reclaim maximum agriculture land and maintain the surrounding environment.

Besides the aforesaid, Drainage Research Centre (DRC), of the PCRWR, Islamabad (formerly known as DRIP), where researches are conducted, practised, and adopted to observe and assure proper crop wise water application rate and it’s maturation period. But the farmers have not availed the benefits of the technology. It is astonishing to note that despite the functioning of high cost-projects in the country, people still are not acquainted with these.

Over development and pumpage in fresh ground water has affected the environment and is the cause of intrusion of saline ground water, (SGW) into fresh ground water.

The pollution of ground water is enhanced due to population growth, putrid municipal facilities, use of fertilizers, pesticides and insecticides in agriculture on large scale, and the disposal of industrial waste in drains and ponds, as well. Moreover, the dust and waste disposal on the land from cattle feeds, tannery and poultry farms have polluted the environment causing asthmatic allergy, T.B., malaria, cholera, skin disease, tetanus and polio, etc.

Remedial measures: The sprinkler irrigation system has been spread out in more than 35 countries offering no extra labour charges and is remunerative and efficient, both in humid and arid regions by saving the water and controlling the pollutants. It is also a good remedy to control the polluted environment duly caused by dust and waste disposal from the cattle feedlots areas.

The use of chemical fertilizers should be banned as it has badly affected the environment, poisoned the vegetables, reduced the fertility of soil, and deteriorated the quality of all agriculture produces, thus straining the health of human beings.

This system has a merit to adopt the EM (Effective Micro-organism) technology, based on simple purely manual fertilizer absolutely free from side effects. The technology invented by (TERU HIGU) Canada-Japan is economical, controls the pollutants, and improves the crop intensity.

The farmers need to be motivated and trained about proper use of water for crops, for controlling and getting rid of the pollutants, of the ground water and waterlogging/salinity. Water laws should be enacted and enforced, and the unlined conventional irrigation system should promptly and immediately be lined up, to avoid over development and over pumpage of ground water and minimize the water losses.