Getting surface water from remote scheme should not be a problem as long as the evaporation and transmission losses are reasonable.

The article below will also give more ideas on this question

Article Reclamation of Land and Improve Water Productivity of Jaffna...

It is essential to provide treated water for drinking purposes in Jaffna Pennisula as the groundwater quality is deteoriating. There is a PhD research work done under my supervion by Dr Thushaniy will tell more about it. Further in my Climate change predictions using HadCM3 general circulation model shows that the recharge will be reduced by nearly 50% in 2050s in Jaffna Pennisula which will cause severe problems in groundwater use as well as quality. I may suggest to increase up to 30% or 40% of the surface irrigation schemes for domestic purposes.

Thanks for very constructive comments. I want more comments from other researchers also.

I have attached a book of mine that will also give more taught s on this issue

Book WATER RESOURCES & AGRICULTURE DEVELOPMENT STRATEGY FOR NORTH...

This is also one of the comment from a senior engineer in the field of water supply

It will be very useful in this discussion

Historical evidence suggest that extracting ground water from the peninsula for supply of drinking water and agricultural water needs is not sustainable in the long term. Number of risks were identified namely,

1. Lime stone aquifer with piping ( two different areas within a short distances does not yield the same quality of water )

You could do a survey of all the wells and establish these facts.

2. The quantity and quality of the source water to Jaffna town has deteriorated over the years and not sustainable for long term needs. (Remember we don’t have a sewerage system for Jaffna )

3. Mid 1900’s saw the sea water intrusion issues for the peninsula and number of barrages were built to flush out the catchments with the birth of Rivers for Jaffna Project initiatives ( now spoken by D.L.O Mendies ). Good idea but not became reality over the past 70 years.

4. Question is how long the community has to wait to receive adequate safe drinking water and sanitation? This is 21st Century with knowledgeable people, who can bring in new technologies to meet the basic human needs, at affordable costs and sustainable into the future.

5. There are number of factors that have changes since my days at NWS&DB, when ideas were conceived for the supply of water to Jaffna peninsula namely.

· Impacts of climate change in the region.

· Availability of new affordable technology for water and sewerage schemes.

· Identification of disease causing organisms in drinking water (Blue Green Algal Toxins ,Protozoa and Virus)

· Reuse of wastewater effluent and bio solids for agricultural use. ( Nutrient Recovery )

· Affordable Brackish/Sea Water desalination Reverse Osmosis Membranes.

6. Your question: Is it ok to get surface water from far away irrigation schemes?

In my view the question should be framed differently. How much of irrigation water is available, how much is needed for irrigation and what is available for other uses?

All over the world famers have a soft spot in the community and they don’t like any water taken away from them even its wasted through

leakage, poor farming practices, or through evaporation by just keeping in storage.

The idea behind taking water from Irranamadu tank was based on the fact that only a small portion of the expanded volume of water is

transferred to Jaffna peninsula. (I have the full business case if you haven’t seen it already)

· Allows more fresh water into the peninsula allowing the ground water table to recover.

· Provides community immediate relief ( when competed in couple of years ).

· Allows economic growth, tourism and other related activities

· Protect public health by safe drinking water and sanitation

7. While all of the above short/medium term projects are underway, further work ( possibly though the new Engineering Faculty ) should be undertaken in the following areas.

· Climate change impacts – water resources, quantify and quality.

· Integrated water cycle management planning for the peninsula. (Similar to Singapore)

· Use of alternative sources of raw water and treat it for “fit for purpose” products. (must be used as many times as practicable, before letting it flow into aquifer/sea)

· Nothing is free. Development of an affordable pricing structure. User pays system to sustain the assets and operate them into the future.

· Decentralised water systems even with RO technologies. ( use of wind and solar power )

· Delivery – Public Private Partnerships ( 30 year contracts ) . No capital needed upfront, but ability to pay a toll over the 30 years. (There are many international companies ready to provide such services )

· Training of local people to meet the new challenges.

All very sensible, knowledge based and balanced comments. Important thing to remember is that there is more than one choice. All choices have pluses and minuses. We have to choose the one which (a) gives more pluses and manageable minuses (b) is economically and environmentally sustainable (c) meets the needs of all communities and (e) democratically acceptable.

I find the integrated approach to provide piped water supply and sewerage system with sewage treatment and recycling arrangements very attractive in that it gives a complete solution, if implemented properly, to the drinking water and sanitary needs of the most populated city in the NP. Linking additional sources of water to Iranaimadu water is fundamental to make this project viable. I hope engineers pay attention to this crucial aspect while taking this project forward.

It cannot be food or water. It has to be food and water. Both needs to be accommodated in addition to livelihood issues of farmers. I think now engineers have got the balance right.

One of a costly but probable solution is desalination plant for the area. At present technology is advanced in desalination industry and many countries are building those plants to overcome drinking water issues. I am not sure how far it is practicable in a country like Sri Lanka due to the cost of construction and maintenance.

For the irrigation... as proposed my many professional integrated approach is sustainable. Pumping ground water excessively will be a short term solution and it can have adverse negative effects in future.

Due to lack of a sewerage system groundwater pollution by septic tanks should be serious. Since agriculture in the area is booming non-point source pollution will be significant in the area although it mainly depend on rainfall and wind.

In Sri Lanka, another issue is water wastage in agriculture.

Thanks Duminda for your very constructive comments

The document added end will be usefull for this discussion

Data Water Utility and Management Policy for Effective Sharing of...

This is also useful for this discussion

Book WATER RESOURCES & AGRICULTURE DEVELOPMENT STRATEGY FOR NORTH...

This article will also add some thing for a fruitful discussion

Article Reclamation of Land and Improve Water Productivity of Jaffna...

According to our research findings in Jaffna, shallow groundwater is heavily polluted due to agricultural activities. I think surface water too has polluted similarly. Better to locate deep groundwater well after testing for water quality parameters and if within limits better to use for drinking purpose. Surface water from irrigation schemes need to be treated before using for domestic purpose.