GUJARAT TECHNOLOGICAL UNIVERSITY

Chandkheda, Ahmedabad

Affiliated

Government Engineering College,

Bhavnagar. A

Project Report

On

Salinity Prevention

Under subject of

DESIGN ENGINEERING - I

B.E. II, Semester – III

(Civil Engineering Branch)

Submitted by:Group: 11

Sr. Name of Student Enrollment No.

1. Nitin Charel 130210106011 2. Kartik Hingol 130210106030 3. Bhavik Shah 130210106049 4. Digvijay Solanki 130210106055

Prof. D.J. Langaliya

(Faculty Guide)

Prof. V.S. Dave

Head of the Department

Academic Year

(2014-2015)

GOVERNMENT ENGINEERING COLLEGE

BHAVNAGAR -

CERTIFICATE

This is to certify that Bhavik Shah, Kartik Hingol, Digvijay Solanki and Nitin Charel of B.E. 3 rd semester , Civil Engineering Department, has satisfactorily completed his Project, of subject Design Engineering-I during academic year 2014-15 and submitted on Nov 24, 2014.

STAFF IN CHARGE HEAD OF DEPARTMENT

ACKNOWLEDGMENT

This dissertation would not have been possible without the guidance and the help of

several individuals, who in one way or the other have contributed and extended their

valuable assistance in the preparation and completion of this project.

First and foremost, we would like to take this opportunity to thank our project guide

Prof. D.J. Langaliya and Prof. K.R. Maiyya, for their patience, guidance,

motivation, and utmost support towards completion of the project.

He has guided us towards obtaining the solution consistently so that we are able to

complete our project on time with the tight schedule. He is a tremendously good

guide, who exhibits his extensive cares, experiences, disciplines and guidance towards

his project students.

We would also like to thank other faculty members, classmates, friends who have

contributed in our project and also for their moral support and encouragement.

Last but not least, we would like to show our deepest thankfulness to our family and

loved ones, who have shown us their concern and full support.

Bhavik Shah .

Kartik Hingol .

Digvijay Solanki;

Nitin Charel .

ABSTRACT

Fresh water is the basic requirement of all living beings on this planet. We cannot think our life without fresh water and it is available only 1% of the total water on the earth. We all know how badly it is been utilized and how it is wasted. Also there is also the increasing amount of salinity in the fresh water because of sea water intrusion and other factors.

Due to sea water intrusion, the saline water is mixing with fresh water and the quality of the fresh available water is decreasing day by day.

So we need to study the causes, effects and prevention techniques of Salinity for the betterment of water and ours too. Also the government of India as well as Gujarat has taken up a lot projects for the prevention in the coastal regions for the same.

OBJECTIVES

To understand the process of Sea water intrusion.

Study the causes of Sea water intrusion.

Study the effect of salinity on coastal areas.

Study the effect of salinity on Human health.

To reduce the merging of sea water in to ground water.

To know about the ongoing government projects to do the same.

TABLE OF CONTENT

1. INTRODUCTION

2. SEA WATER INTRUSION

3. CAUSES Of SALINITY

4. EFFECTS OF SEA WATER INTRUSION

5. PREVENTIVE MEASURES

6. GOVERNMENT PROJECTS

7. CONCLUSION

Introduction

First of all we need to know what salinity is.

Salinity is the saltiness or dissolved salt content of a body of water or in soil. Salinity is discovered in two physical factors of our earth. They are:-

1. Soil 2. Water

Our interest of study is the salinity in water near the coastal areas in Gujarat and their effect on fresh water reservoirs and health of humans.

India has a dynamic coast line of about 7500 km length, including the main land coast line of about 5400 km. Nearly 25 percent of the total population of India resides in the coastal tracts of the country. A number of important towns and cities, viz., Mumbai, Goa, Cochin, Chennai, Visakhapatnam & Kolkata are located along the coast.

The State of Gujarat has the longest coastline of 1600 km, which is about one third of the total coastline of India. Of this, Saurashtra and Kachchh districts have an 1125 km coastal belt from Bhavnagar to Lakhpat. Due to heavy withdrawal of groundwater and very meagre recharge sources (only rainfall), ingress of sea water has converted the available groundwater resources into a saline belt, rendering cultivable land useless and the water in the wells saline and unsuitable for irrigation and drinking purposes. The phenomenon of salinity ingress has affected 779 villages as of 1976, covering a population of 13.30 lakh and an area of 10.65 lakh hectares. The Government of Gujarat (Government) appointed (1976 and 1978) High Level Committees (HLC) to suggest measures for prevention of ingress of salinity and measures to remedy damages that had already occurred. The HLCs had recommended commissioning of a yearly study to monitor the areas that had been affected by salinity ingress. The last such yearly exercise was carried out in 2007-084 and as per the report following this exercise, there had been an overall increase of 15 per cent in salinity ingress area, involving an additional affected area of 88,947 hectares when compared with the base data for the period 1977 to 1984.

Thus from above, the main reason for Salinity is Sea water Intrusion. So let’s study the sea water intrusion.

Sea Water Intrusion

Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to contamination of drinking water sources and other consequences. Saltwater intrusion occurs naturally to some degree in most coastal aquifers, owing to the hydraulic connection between groundwater and seawater. Because saltwater has a higher mineral content than freshwater, it is denser and has a higher water pressure. As a result, saltwater can push inland beneath the freshwater. Certain human activities, especially groundwater pumping from coastal freshwater wells, have increased saltwater intrusion in many coastal areas. Water extraction drops the level of fresh groundwater, reducing its water pressure and allowing saltwater to flow further inland. Other contributors to saltwater intrusion include navigation channels or agricultural and drainage channels, which provide conduits for saltwater to move inland, and sea level rise. Saltwater intrusion can also be worsened by extreme events like hurricane storm surges.

Hydrology:-

At the coastal margin, fresh groundwater flowing from inland areas meets with saline groundwater from the ocean. The fresh groundwater flows from inland areas towards the coast where elevation and groundwater levels are lower. Because saltwater has a higher content of dissolved salts and minerals, it is denser than freshwater, causing it to have higher hydraulic head than freshwater. Hydraulic head refers to the liquid pressure exerted by a water column: a water column with higher hydraulic head will move into a water column with lower hydraulic head, if the columns are connected.

The higher pressure and density of saltwater causes it to move into coastal aquifers in a wedge shape under the freshwater. The saltwater and freshwater meet in a transition zone where mixing occurs through dispersion and diffusion. Ordinarily the inland extent of the saltwater wedge is limited because fresh groundwater levels, or the height of the freshwater column, increases as land elevation gets higher.

Causes of Sea water intrusion:-

The main causes of sea water intrusion are:-

Natural Occurance of Seawater Intrusion

1. Ground Water Extraction2. Canals and Drainage networks

Ground Water Extraction:-

Groundwater is the portion of the Earth's water cycle that flows underground. Groundwater originates from precipitation that percolates into the ground. Percolation is the flow of water through soil and porous/fractured rock. The water table separates the saturated, or aquifer zone, from the unsaturated, or vadose zone, where the water does not fill all the voids or spaces in the soil or rock (Fig. 1). The general trend is for water in the unsaturated zone to move downward until it reaches the water table. On the other hand, water in the saturated zone moves primarily along horizontal hydraulic gradients, from higher to lower elevations. The ocean is the natural sink for groundwater flows.

Groundwater extraction is the primary cause of saltwater intrusion. Groundwater is the main source of drinking water in many coastal areas of the United States, and extraction has increased over time. Under baseline conditions, the inland extent of saltwater is limited by higher pressure exerted by the freshwater column, owing to its higher elevation. Groundwater extraction can lower the level of the freshwater table, reducing the pressure exerted by the freshwater column and allowing the denser saltwater to move inland laterally. In Cape May, New Jersey, since the 1940s water withdrawals have lowered groundwater levels by up to 30 meters, reducing the water table to below sea level and causing widespread intrusion and contamination of water supply wells.

Groundwater extraction can also lead to well contamination by causing upwelling, or upcoming, of saltwater from the depths of the aquifer. Under baseline conditions, a

saltwater wedge extends inland, underneath the freshwater because of its higher density. Water supply wells located over or near the saltwater wedge can draw the saltwater upward, creating a saltwater cone that might reach and contaminate the well. Some aquifers are predisposed towards this type of intrusion, such as the Lower Floridan aquifer: though a relatively impermeable rock or clay layer separates fresh groundwater from saltwater, isolated cracks breach the confining layer, promoting upward movement of saltwater. Pumping of groundwater strengthens this effect by lowering the water table, reducing the downward push of freshwater.

Canals and Drainage networks:-

The construction of canals and drainage networks can lead to saltwater intrusion. Canals provide conduits for saltwater to be carried inland, as does the deepening of existing channels for navigation purposes. In Sabine Lake Estuary in the Gulf of Mexico, large-scale waterways have allowed saltwater to move into the lake, and upstream into the rivers feeding the lake. Additionally, channel dredging in the surrounding wetlands to facilitate oil and gas drilling has caused land subsidence, further promoting inland saltwater movement.

Drainage networks constructed to drain flat coastal areas can lead to intrusion by lowering the freshwater table, reducing the water pressure exerted by the freshwater column. Saltwater intrusion in southeast Florida has occurred largely as a result of drainage canals built between 1903 into the 1980s to drain the Everglades for agricultural and urban development. The main cause of intrusion

was the lowering of the water table, though the canals also conveyed seawater inland until the construction of water control gates.

These are the basic reason for sea water intrusion which leads to salinity in ground water. There are also some other reasons like:-

Higher seawater density than freshwater.

Higher seawater density than freshwater:-

f = freshwater density = 1.0g/cm3

s = saltwater density = 1.025g/cm3

The law of nature is that object with higher density flows toward the object with lower density. Thus the sea water which has higher density (can reach up to 1050 Kg / m3) than the fresh water (1000 Kg / m3) will flow towards the fresh water area when the water from there is removed because of extraction.

And others are

Mismanagement of ground water due to over-irrigation and water loss through high run-off.

Inefficient use and wastage of water by farmers. Cultivation of high water intensive crops like sugarcane, banana etc.

resulting in lowered water table and ingress of saline water into groundwater.

Over-exploitation of ground water to meet needs of growing population. Breaking up of joint family system resulting in fragmentation of land,

leading to rampant increase in no. of wells and extensive use of diesel and electrical pumps.

High run off due to improper or inadequate water harvesting. Recurrent droughts.

Ghyben-Herzberg Relation:-

The first physical formulations of saltwater intrusion were made by W. Badon-Ghijben (1888, 1889) and A. Herzberg (1901), thus called the Ghyben-Herzberg relation. They derived analytical solutions to approximate the intrusion behavior, which are based on a number of assumptions that do not hold in all field cases.

The figure shows the Ghyben-Herzberg relation. In the equation,

The thickness of the freshwater zone above sea level is represented as   and that below sea level is represented as . The two thicknesses   and , are related by   and   where   is the density of freshwater and   is the density of saltwater. Freshwater has a density of about 1.000 grams per cubic centimetre (g/cm3) at 20 °C, whereas that of seawater is about 1.025 g/cm3. The equation can be simplified to

.

The Ghyben-Herzberg ratio states, for every foot of fresh water in an unconfined aquifer above sea level, there will be forty feet of fresh water in the aquifer below sea level.

In the 20th century the higher computing power allowed the use of numerical methods (usually finite differences or finite elements) that need fewer assumptions and can be applied more generally.

Effects of Salinity:-

Agricultural production

Water moves into plant roots by a process known as osmosis, which is controlled by the level of salts in the soil water and in the water contained in the plant. If the level of salts in the soil water is too high, water may flow from the plant roots back into the soil. This results in dehydration of the plant, causing yield decline or even death of the plant. Crop yield losses may occur even though the effects of salinity may not be obvious. The salt tolerance of a specific crop depends on its ability to extract water from salinized soils. Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction. Some ions (particularly chloride) are toxic to plants and as the concentration of these ions increases, the plant is poisoned and dies.

Water quality

The most significant off-site impact of dry land salinity is the salinization of previously fresh rivers. This affects the quality of water for drinking and irrigation—with serious economic, social and environmental consequences for both rural and urban communities. High levels of salts may affect the taste of drinking water. Chloride in particular has a low taste threshold. Sodium and magnesium sulphate levels in drinking water may produce a laxative effect and reduce the suitability of a water supply for grazing animals.

Ecological health of streams

Salt interacts with in-stream biota (animals and plants), changing the ecological health of streams and estuaries. The greatest threat to biodiversity is from the loss of habitat—both on land and in water. Riparian zones are particularly at risk as they occupy the lowest parts of the landscape where much of the saline groundwater is released to the surface. Salts also help fine materials (such as suspended clay particles) to flocculate, allowing more sunlight to penetrate rivers. This may lead to more harmful algal blooms if there are suitable environmental conditions.

Infrastructure and fixtures

Impacts include large decreases in the lifespan of road pavements when groundwater levels rise to within 2 metres of the pavement surface. As in other situations, capillary action will assist to draw the salt-laden water to the surface. Salt also corrodes and destroys the properties of bitumen, concrete and brick structures. Damage to infrastructure including houses, roads and playing fields, has been particularly high in a number of cities and towns. Salinity damage has also occurred to country roads and farm tracks and buildings.

Irrigation

All irrigation water contains some salts, which may remain on the soil surface or on leaves of plants after evaporation. Therefore, any irrigation system has the potential to deliver an increased amount of salt to the soil.

Impact of salinity on health Inhabitants of coastal areas often have poor health, mainly due to lack of potable drinking water in the coastal district of Amreli, Jamnagar and Kachchh. Non-availability of potable water forced people to drink saline water which can cause water-borne and other diseases like kidney stones, gastric problems etc. A baseline study carried out (2007-08) in 1165 villages by CSPC indicated that 890, 753 and 337 villages reported high number of cases of kidney stones, gastric problems and fluorosis respectively as shown in Table.

Table: Villages affected by various diseases at various distances from sea coast

Diseases type Total No. of villages facing health problems

Distance of affected villages from sea coast facing health

Kidney Stones

890 347 236 307

Fluorosis 337 151 87 99Gastric Problems

753 269 207 277

< 5 km 5 to 10 km > 10 km

Preventive Measures:-Salinity Control Techniques:-

(1) Tidal Regulators and Bandharas at river (2) Fresh Water barriers (3) Extraction barriers(4) Static barriers

Tidal Regulators and Bandharas at river:-

Tidal Regulators are used to stop the ingress of sea water. The top portion of the gates were to be kept above the maximum tide level to prevent entry of tide water into the land and the gates were to be opened during floods to allow the discharge of excessive flood water to prevent submergence of the land areas in the upstream.

Bandharas are also used to stop the ingress of sea water. In this method a bandh / blockage is made across a river to stop its flow to merge in the sea. Therefore the water remains pure without the salts. A canal or pipe is used to utilize the pure water for agriculture, drinking, industries and other human activities.

Physical Barriers. Subsurface physical barriers such as sheet pile, cut-off walls, clay slurry trenches under earth dams, and impermeable clay walls are routinely used by engineers in the field to control the movement of water and other liquids including the containment of hazardous waste materials. It is also possible to inject materials that form a zone of low permeability. Figure 6-10 illustrates a cross-section of a typical physical barrier.Barriers require complete depth of cut-off to be effective.

Extraction Barriers. Extraction barriers have been used in various locations in order to prevent or reduce saltwater intrusion. Extraction barriers may withdraw some freshwater that would otherwise be useful and thus may not be a valuable option where water supplies are scarce. In addition, problems with saltwater corrosion must be overcome. However, a major problem with the extraction barriers are that withdrawal of saltwater and the inadvertent withdrawal of some freshwater cause the water levels to fall substantially throughout the basin. The increased lift and the cost of wells going dry often become costly in time. Furthermore, although a complete cut-off extraction barrier does not have to be completed all along the coast, saltwater intrusion can around the barrier. The lower levels also encourage saline water from above or below to move vertically into the aquifer. However, vertical leakage may occur from above or below.

Freshwater Injection Barriers. Figure 6-12 illustrates a typical injection barrier in operation to control the saltwater intrusion for cases where the sea level is in excess of freshwater levels. In contrast to the extraction barrier, with an injection barrier, freshwater is injected into, the aquifer through a line of wells along the coastline. The higher groundwater levels along the injection barrier prevent saltwater intrusion from occurring. A proper design of well spacing and location must be performed to ensure that saltwater does not intrude around the injection barrier, in between individual wells, or move vertically from above or below. The problems with injection wells include the fact that a relatively large number of wells is required, a high maintenance cost will be necessary to prevent plugging of wells, and most important, a source of freshwater will be needed.

Recharge Techniques:-

(1) Check dam (2) Recharge Wells

(3) Spreading Channel

Check dam:-

Check dam is a structures across the gully / waterway with packed stones or stone masonry structure. This is constructed in the middle reaches of the gully or stream. The upstream stored water is useful for recharge as well as supplemental / life-saving irrigation.A check dam placed in the ditch, swale, or channel interrupts the flow of water and flattens the gradient of the channel, thereby reducing the velocity. In turn, this obstruction induces infiltration rather than eroding the channel. They can be used not only to slow flow velocity but also to distribute flows across a swale to avoid preferential paths and guide flows toward vegetation. Although some sedimentation may result behind the dam, check dams do not primarily function as sediment trapping devices.

The water stored in the check dam is injected into the ground water so that the fresh water increases and the sea water is pushed back.

Recharge Well:-

Recharge wells can be of two types - (a) Injection well, where water is “pumped in” for recharge and (b) Recharge well, where water flows under gravity.

The Injection wells are similar to a tube well. This technique is suitable for augmenting the ground water storage of deeper aquifers by “pumping in” treated surface water. These wells can be used as pumping wells during summers. The method is suitable to recharge single aquifer or multiple aquifers. The recharge through this technique is comparatively costlier and required specialized technique of tube well construction and maintenance to protect well from clogging. It is better if an abandoned tube well is used as a recharge well which will be a cost-effective structure.

The recharge well for shallow water table aquifers up to 50 m are cost effective because recharge can take place under gravity flow only. These wells could be of two types, one is dry and another is wet. The dry types of wells have bottom of screen above the water table. In such wells excessive clogging is reported due to release of dissolved gasses as water leaves the well and on other hand redevelopment methods have not been found effective in dry type of wells. The wet type of wells are the wells in which screen is kept below water table. These wet type wells have been found more successful.

INDUCED RECHARGE

It is an indirect method of artificial recharge involving pumping from aquifer hydraulically connected with surface water such as perennial streams, unlined canal or lakes. The heavy pumping lowers the ground water level and cone of depression is created. Lowering of water levels induces the surface water to replenish the ground water. This method is effective where steam bed is connected to aquifer by sandy formation.

GOVERNMENT PROJECTS

Spreading Channels:-

Scrutiny of works pertaining to Spreading Channels revealed the following:

(a) Out of 526 km of SCs recommended by HLCs, only 100 km had been completed (March 2010). Due to the absence of links between reservoirs through the construction of SCs, sea water continued to intrude into surrounding areas of completed structures i.e. Bandharas and Tidal Regulators. Therefore, the aim of reducing salinity ingression could not be fully achieved in these areas. Out of the four reaches, in the Bhavnagar-Una Reach and the Malia-Lakhpat Reach, as against recommendations for construction of 60 km and 166 km of SCs respectively, there was no construction as of March 2010. In the Una-Madhavpur Reach, the entire recommended length of 60 km of SC had been constructed. The Secretary stated (May 2010) that due to shortage of funds and non-availability of sufficient technical manpower, the work of the SCs could not be taken up simultaneously. The reply is not acceptable as there were savings of ` 112.34 crore during 2005-10. On this being pointed out during the exit conference (July 2010), the Secretary stated that SC works would be taken up and completed expeditiously.

Measures taken by Government for salinity ingress:-

Looking to the gravity of salinity and its devastating effects, Government had formed a High level Committee- 1 in 1976 under the then chairmanship of the Chief Secretary Shri H.K.L.Kapoor for Una-Madhavpur area and a High Level Committee-2 in 1978 under the Chairmanship of the then Chief Secretary Shri K.Shivraj for Una-Bhavnagar and

Madhavpur-Maliya area for study of issue of salinity and for its solution.After visit of the affected areas, these Committees had suggested the following measures of various salinity Ingress under four scientific systems:-

Sr.No. Various Works of Salinity Ingress Under Scientific System

1 Management SystemRegulation of lifting underground water and change in crop – System

    Change in crop System

2 Recharge System Check-Dam

    Recharge-Dam

    Recharge-Well

    Recharge Reservoir Spreading Channel

3Salinity Ingress System

Tidal Regulators, Weirs

    Fresh Water Barrier

    Extraction Water Barrier

    Static Barrier

4Coastal Land Reclamation

Rejuvenation of salinity land of oceanic areas

 

Works undertaken as per the recommendations made by High Level Committee 1 and 2 and Details of Progress thereof.

The High Level Committee 1 suggested various works of Salinity Ingress Prevention works of Rs.64 crore (Revised Cost of Rs. 100.24 Crore) in Una-Madhavpur area whereas the High Level Committee 2 suggested works of salinity Ingress Prevention works of Rs. 168.70 Crore (Revised Cost of Rs. 802.54 Crore)

And of Rs. 370.42 crore (Revised Cost of Rs. 1427.30 Crore) respectively in the areas of Una-Bhavnagar and Madhavpur-Maliya out of the aforesaid works suggested by both the Committees. Works of construction of 13 Tidal Regulators, 29 Bandhara, 15 Recharge Reservoirs, 661 Check Dams, and 28 Recharge Tanks, 4487 nala Plugs and afforestation in 5867 hectors of land have been completed.

Spreading Channels:- Total Length 360 kms. Undertaken 331 kms.

Completed 141 kms. Under Progress 105 kms. Under sanction/Research 85 kms.

Upon completion of this ambitious extension canal project. The empty reservoir/ponds of one basin having less rainfall can be filled with the river water. Moreover benefit of recharge is also made available. In addition, upon completion of this extension canal works, 33700 hector area will be benefited directly and indirectly. As the works have been completed in 141 km. length area, a total of 19569 hector area has been directly and indirectly benefited.

Out of the aforesaid Salinity Ingress prevention projects, at present works of 33 projects out of the projects worth Rs. 107.70 crore are under progress in the 6 districts of coastal regions of Saurastra.Planning of remaining projects of salinity ingress and financial assistance from outer resources 

As mentioned above, most of the works as suggested by the High Level Committee-1 have been completed in the areas suggested by the Committee and benefits have been accrued. It is essential to complete the remaining works of Salinity Ingress Prevention in limit as suggested by the committee to eradicate this issue completely. As the works suggested in the areas of Committee-2 are going on as per the current financial availability, financial assistance has been provided by the 12th finance commission, 13th Finance commission and NABARD to avail the benefits estimated for these works.

Looking to the gravity of Salinity Ingress, the Central Government has allocated assistance of Rs. 75.10 Crore in the 13th Finance commission under the State Special Need for the works of Salinity Ingress Prevention Works in same. In this connection at present as per revised proposals 33 Salinity Ingress Prevention projects of advance stage such as 1 Tidal Regulators, 6 Bandhara, 2 Recharge Reservoirs, 11 Recharge Tank, 5- Spreading Channel, 5- Redial canal etc. have been included in the programme at the cost of Rs. 80.57 Crore, out of which 12 projects have been completed whereas 15 are going on Upon completion of these 33 projects, quota of 11.77 million cubic meters of fresh waters will be stored, by which, 17811 hector land will get direct and indirect benefit. It is planned to complete the aforesaid scheme by March, 2015.

Proposal forwarded for financial assistance under NABARD NABARD has sanctioned a loan of Rs. 204.03 crore under RIDF-12 by accepting the

proposal of 36 Salinity Ingress Projects to the tune of Rs. 227 crore to be taken up on priority basis, out of the various Salinity Ingress Projects. This proposal includes 5 Tidal Regulators, 8 Weirs, 9 Recharge Reservoirs and 14 extension / radial canal works. Out of these, 27 projects have been dropped and 2 projects have been proposed to be included

under the 12th Finance Commission. At present 7 projects have been included under the NABARD at a cost of Rs. 37.25 Crore. Upon completion of all these projects, water quota to the tune of 22.41 million cubic meters will be stored and 7637 hector land will be directly and indirectly benefited. The aforesaid projects are completed by March 2014.

Benefits accrued by the salinity ingress projects

The works of Salinity Ingress have been undertaken under the recharge and Salinity Ingress System which aim at recharging the fresh water, increase the quality of underground water and prevent salinity of surface water and underground water due to spreading of tidal water. The advancement of saline tidal water has been prevented due to the tidal regulators and weirs which have been completed. Moreover the damage occurring to the fertile agricultural land has also been stopped and the underground water being affected by Salinity earlier has also been prevented due to this. Moreover, the following benefits have accrued upon completion of aforesaid works of Salinity Ingress :- 74512 hector lands have directly to indirectly have been benefited for irrigation upon storage of 318.04 million cubic meters of fresh water. Quality of underground water has increased and an average rise of 2.50 metres has been observed in the underground water surface. Looking to the advancement rate of Salinity line of 0.50 to 1.00 k.m. per annum, further 2.26 lakh hectors of land have been prevented from the onslaught of salinity on the basis of completion of these works. 2000 line of T.D.S. has been shifted towards the coastal region from non-coastal regions as per the situation observed in 1988. Due to increase in crop yields, the cost of the agriculture land has also increased. Due to increase in the socio – economical condition (of people of this area), overall prosperity of this region has also been increased.

 KACHCHH

The Coastal strip between Malia & Lakhpat covers a linear distance of about 360 kms. All along the coast, there is a grave situation of Salinity in ground water.

Total geographical area investigated from Malia to Lakhpat is 3712 sq.km. Comprising of 245 villages of 7 talukas in Kachchh District. Out of these 245 villages, almost all are affected by salinity.

The High Level Committee visited the Malia-Lakhpat reach. The following measures are suggested for providing an effective solution to the problem.

1 Management Techniques :

(i) Change in Cropping pattern,(ii) Regulation of ground water extraction

2 : Recharge Techniques :(i) Checkdams,(ii) Recharge Tanks,(iii) Recharge Wells,(iv) Spreading Channels,(v) Afforestation,(vi) Gully / Nalla Plugs

3 : Salinity Control Techniques :(i) Tidal Regulator, (ii) Bandharas, (iii) Protection from Salt pans, (iv) Coastal Bunds.

4 : Coastal Land Reclamation :(i) Reclamation of Coastal Saline by leaching.

The High Level Committee-II suggested 15 No. of Tidal Regulator, 40 No. of Bandhara, 740 No. of Checkdams, 25 Recharge Tank, 150 No. of Recharge Well, 166 km. Spreading & Connecting Channels, 2000 No. of Nalla Plug, 10000 hect. Of Reclamation of Coastal Land of an estimated amount of Rs. 186 Crores.

No. of Tidal Regulator, 3 No. of Bandhara and 110 No. of Checkdams completed prior to 2005 while 47 No. of Bandhara, 130 No. of Checkdams completed after 2005. 500 No. of Checkdams, 25 Recharge Tanks, 150 Recharge Wells and 130 km. Spreading & Connecting Channels are under progress and planning.

The Govt. of Gujarat, Narmada, Water Resources, Water Supply & Kalpsar Deptt., Sachivalaya, and Gandhinagar vide his letter No. TFC/ 2010/ 670(4)/ K-7, M I Cell, Dt. 28/12/2011 had approved action plan for 13th Finance Commission in which Salinity Ingress Prevention works taken.

The details of works are as under :-

Sr. No.

  Estimated cost (Rs. in Lacs.)

(i) 500 No. of Checkdams 4000

(ii) 25 No. of Recharge Tank 1000

(iii) 150 No. of Recharge Well 1500

(iv) 20 No. of Coastal Bund 1000

  Total : 7500

The probable cost of the revised action plan will be limited to Rs. 7500 lacs same as per the original planning of Rs. 7500 lacs.

Conclusion:-

Thus from the above study we can understand the effect of the salinity and how worse it can be for all. It should be taken seriously and the government has taken it seriously in many extend and done many projects for the betterment. The completion of the projects in the slower side and there are failures in some of the projects too. Still the government is doing a lot and some of its projects are successful in reducing the Salinity ingress.

Reference:-

1. www.cspc.org.in/ 2. en.wikipedia.org/wiki/Saltwater_intrusion 3. Images from https://www.google.co.in/search?

q=seawater+intrusion&es_sm=93&biw=1242&bih=606&tbm=isch&tbo=u&source=univ&sa=X&ei=7d52VNrDNIme8QW5m4KACQ&sqi=2&ved=0CCcQsAQ

4. www.wrd.org/engineering/seawater-intrusion-los-angeles.php 5. http://water.epa.gov/type/groundwater/uic/class5/upload/

2007_12_12_uic_class5_study_uic-class5_classvstudy_volume20-salineintrusionbarrier.pdf

6. http://guj-nwrws.gujarat.gov.in/showpage.aspx? contentid=1470&lang=english

7. http://iced.cag.gov.in/wp-content/uploads/2014/02/3.-PA-of-Salinity- Ingress-Prev.-Prog.-Gujarat.pdf