2 LITERATURE SURVEY

2.1 FLOODS AND ISSUES IN GIN GANGA PROJECT 2.1.1 General Gin Ganga is a river situated in the South Western Region of (Fig. 1). It drains an area of 960sqkm at the sea out fall, which is Ginthota. The river is 112.5km long, with its source reaching Abbey Rock (Elevation 1293m MSL). The river drains part of Southern Province and passes Udugama, Mapalagama, Agaliya, and Baddegama, Dodangoda and flows into the sea at Ginthota (Fig. 2). The last stretch of Mapalagama to Gintota of the river is through flat lands. During rainy season floodwater inundates the Gangaboda Pattuwa and Four Gravets (Bope-Poddala, Akmimana DS Divisions) in (Fig. 3). The disaster caused by floods menaced 6200ha of paddy lands and 33000 people living in 6000 houses and affected transportation and communication in the lower basin. Nearly 216 000 people lived in the basin and 60000 people lived in the vicinity of floods in lower basin (PDR, GRP, 1975).

The in 1972 invited the Government of People's Republic of China to recommend a plan to control the flooding in the river basin. Chinese Engineers designed the flood control project. The Gin Ganga Regulation Project (GRP) was completed in 1983 by the joint assistance of Chinese and Sri Lanka Governments. Irrigation Department of Sri Lanka commenced operation and maintenance work in 1983. In 1972, about 22000 people living in 4000 houses occupied the project area below Agaliya. Gin Ganga project declared an unprotected area of 2540ha with 830 houses with 4000 inhabitants. Backwater effect inundates 78ha in upstream of Agaliya. Project occupies about 225 ha of paddy lands between flood bunds on both sides of river (PDR, GRP). Project included 6200 ha of paddy lands, which is 45% of the total. Electric pumps were provided to dispose drainage water from 3188ha of paddy lands. Another lOOOha of rainfed paddy lands in the upstream sub basins were unaffected and were taken as free from high scale flooding. 1740ha of Holuwagoda basin was drained by gravity. 800ha of marshy lands were reclaimed and converted as paddy fields in Diviturai.

The cost of the project in 1983 was Rs. 430 million. It included the construction of 10 pump houses, 24.2km long flood bunds, 35km long drainage canals, 21 spill structures, 47 culverts and bridges, one ship lock, one switching station with a separate power 14 supply line from Nugaduwa and the office building at Indigasketiya.

2.1.2 HYDROLOGY

Gin Ganga basin mainly experiences southwest monsoon rains and floods are usually experienced during May - June. Floods also occur during the inter-monsoon period of October - November but to a lesser degree than the May-June monsoons. Average annual flow into the sea is about 1600 million cubic meters and the mean annual rainfall is 3048mm at Neluwa-Tawalama in mid catchment. Available records show that maximum stagnation of floods was for 30 days in May 1940 with a maximum discharge of 1400cumec at Agaliya (IDGauging, 1940). Rainfall and river stage records are available from year 1928 onwards (PDR, GRP, 1975). The Irrigation Department maintains Agaliya and Tawalama gauging stations. Department of Meteorology maintains Galle meteorology station.

Average monthly precipitation records for 1901-1965 period at Beausejour (lower) are given in Fig. 5 (ECIR, 1968) and Monthly precipitation records for 1973 -1994 at Galle are given in Annex F (Met D, 1994), Annex B gives the design flood details (PDR, GRP).

Table 1.1 gives the seasonal precipitation data at Galle and Table 1.2 gives the seasonal evaporation data at Ratnapura. Table 1.3 gives average annual values of data at respective locations in the vicinity.

15 Table 1.1 Seasonal Precipitation Data -GALLE

YEAR Description TOTAL

1990 NE monsoon total = 887mm 1990 NE monsoon 30 year average = 1090mm

1990 SW monsoon total = 1241mm 1990 SW 30 year average = 1290mm 1990 Annual total = 2118mm 1990 Annual 30 year average = 2380mm 1965 Annual 65 year average = 2500mm

Table 1.2: Seasonal Evaporation in Ratnapura (mm)

YEAR Description TOTAL

1995/6 Northeast monsoon total = 623mm 1995/6 Southwest monsoon total = 587mm 1995/6 Annual total = 1210mm 1965/6 Annual total = 1140 mm

Tawalama Station Catchment area = 26 500ha

Coordinates of Tawalama = 0/9 (0.65,2.75)

Coordinates of Agaliya = 0/13 (4.90, 0.90)

Table 1.3: AVERAGE ANNUAL VALUES OF RAINFALL, EVAPORATION, SPECIFIC YIELD OF FLOW, RUN OFF, PEAK FLOW

COMPONENT STATION ANNUAL VALUE REMARKS

Rainfall Neluwa-Tawalama 3048mm 1901/65 period average Galle 2380mm 1960/90 period average Pan evaporation Ratnapura 1210mm Pan evaporation 95/96 Ratnapura 1140mm Pan evaporation 65/66 Runoff Tawalama 911MCM Runoff 95/6 Tawalama 3580mm Rain fall 95/96 Specific yield Tawalama 0.68 1995/6 Volume estimated Gin thota 1600MCM 1901-1965 average Peak flow Agaliya 1400 cumec Peak flow May, 1940 River water quality Wakwella Salinity, Iron River water quality

16 2.1.3 LAND USE PATTERN OF THE PROJECT AREA

Gin Ganga basin is fairly well developed in agricultural pursuits excepting Singharaja forest in the mid-basin. The upper reaches are planted with tea, rubber, coconut and cinnamon. (Fig. 3, Fig. 4, Fig. 6, These data maps were prepared before 1972) Rubber predominates in the lower areas. Paddy lands are in lowland pockets, all along the river amounting to about 14,133ha (PDR, GRP, 1975). About half of paddy lands, situated in the low lands, suffer from periodical floods (ECIR, 1968). The tea plantations are said to contribute to the sediment in water currents. Paddy fields lose finer sediments. Mountains in mid basin also said to have low vegetation due to erosion. The new short rooted bud tea plantations with high foliage reduced the erosion after 1970 (Soil, 1994). Land use map for 1972 in Topographical map of Ambalangoda, sheet number 67, -scale 1:63360- is shown in figures 3, 4 and 6. Low- lands in the basin are about 15% and most are paddy lands, which were concentrated in the lower basin. The cash crop plantations in high lands are about 34 % cultivated with tea, cinnamon and rubber. Domestic areas are cultivated with coconuts and vegetables. About 25 % of the basin is under jungles. Project area had 40% paddy, 20 % rubber, 10 % tea and others in the lowest section. In the upper project area 31% paddy, 30% tea, 30% rubber, 5% gardens and 4% scrubland are available (ECER, 1968). The soil map of Sri Lanka shows red yellow podzolic soils from Udugama to Kimbi ela and red yellow podzolic soils with well-developed laterites and their drainage associates from Kimbi ela to Galle (Panabokke, 1967).

2.1.4 HISTORY OF GINGANGA BASIN

Flooding of Gin basin has a long history. The abundance of aquatic palm known as Gin at Ginthota had given its name to the river. Lower basin had experienced heavy flooding but the effect was well taken for seasonal needs. Though crocodiles were living in the river but the oru paru boats were used for traveling along the river.

Ginthota, Halpathota, Nugethota were reputed landing stations. Water dependent agriculture had been the main living of the population and after 13* century international trade activities had taken its place in lower basin. Galle became a busy harbour to exchange goods from Arabian and Indian vessels. Spices and goods were 17 brought along the river from main land. In 1505 Portuguese ships landed in Galle and fighting for trade rights were intensified. Many foreigners settled in the coastal area and they found the floods as a disaster. In 1648 Dutch took the control of Galle harbour and made a fortress. They traveled up to Mapalagama and created Thanayam rest houses. Cinnamon was newly introduced and bonded labour immigrants were introduced in colonies. Galle became the capital of the low country, when the Kandyan King lost the control over the Galle area. Dutch officers cut new waterways for easy transport. Tax collectors gathered high income using the waterways as checkpoints. Effort had been made during Dutch period to protect certain pockets of areas from floods by means of earth embankments along river and canals but without satisfaction. The Dutch government was protecting banks across Heen Ela in Majuwana and cut a canal to divert water to Hikkaduwa across Gonapinuwala. Dutch canal, which is known as Kepu Ela provided another bypass to take excess water of the river from Ukwatta to Mahamodara. This has provided a water transports service from Galle town to upstream villages using the "Angula" boats. The people to drive these "Angula", upstream from Mahamodera, Ukwatte to Mapalagama, harnessed high tidal drift. Sediments and materials carried by floods are deposited on the Gin Ganga flood plains. Gin Ganga flood plains possess clay deposits, which are used for pottery, brick and tile making while using the same land for paddy cultivation. Sugarcane was also cultivated in the low lands. Vegetables and green leaves are cultivated mostly near Labuduwa, Ukwatte villages.

Sand mining from the riverbed was a long time practice among the villagers. This was accelerated due to cement mortar brick production. Though bamboo plants are found along banks the erosion can be observed during high flows. 2.1.5 THE FLOODING ISSUE

Problem of Gin Ganga flooding was considered as the first and foremost environmental hazard of the district. Government budget allocations for flood relief activities included food and lodging services for the displaced persons. Irrigation Department physically controlled annual floods through the operation of lock gates provided at Dodangoda and Ukwatte across flood bunds (Brohier, 1954).

Daily river flow gauging at Agaliya was commenced in 1940 by the Hydrology

Division of Irrigation Department. River stage was recorded from 1928 onwards. Since then the highest flood had been the one recorded in May 1940, which amounted 18 MRfiV'ERSJTY ^QRATOWA. SRIUg& MORATUWA to 1400 cumecs. This storm was widespread in the wet zone of Sri Lanka. Heavy rainfall in the basin initially creates flooding in Mapalagama area. Then it moves down to Agaliya area in a significant stagnation due to narrowness of the section. Wakwella area is then affected by heavy flooding, which usually lasts for more than a week.

Trans basin flow takes place from Halpathota to Gonapinuwala tract and from

Baddegama to Kimbi ela.

Long lasting floods cut off the transport services. Inundated roadways need frequent repairs. People make use of boats for urgent travel and transport needs. Social and economic damages were very high as the people face enormous difficulties including loss of life and property. Schools remained closed during floods. A significant effect was the rejection of entire area for future development. Flood basins are used for paddy cultivation but fertilizer is not added due to high risk of flooding in many areas.

As a result the crop is not thriving to a maximum level. Average yield is 1-2 tons/ha for paddy.

The land closer to important places like roadways, markets, schools, temples are in demand for building construction but could not be utilized solely due to flood inundation. The area produced tea, rubber, and coconut products for export market in

British period but now demanding more space for village expansion due to high population. Two storied houses were constructed in flood plains to escape from wetting in ground floor. The temple built in Mabotuwana was on elevated piled logs and this made another cultural identity. The sanitary levels were poor due to water borne diseases. People made it a habit to clean wells after floods while unaffected wells were used for (Irinking during floods.

After various investigation studies, (ECIR, 1968 & PDR, GRP, 1975) the plan proposed by the Government of China was executed to control the Gin Ganga flooding which was completed in year 1983. The ECI report of 1968 covered the feasibility studies for flood control below Mapalagama. Agaliya to Mapalagama section of the basin was excluded for the final design.

2.1.6 FLOOD CONTROL ATTEMPTS

There had been several attempts prior to 1975 to control floods. Dutch occupation in

Galle District was important to the development of water transport.

19

76171 Mapalagama to Gintota along Gin Ganga was the main water route for boats. Galle Fort was connected to this major river by a built canal from Ukwatta to Mahamodera across Koppe Ela. This built canal was again joined to a net work of canals in the town area. "Kepu ela" was the Sinhala name given to the new canal meaning "cut canal", which was 10 meters wide, 3 meters deep and 5.75 km long.

Kepu Ela reduced the bulk of floodwater collected at Ukwatta by providing another passage in addition to the Gintota outfall, which gets blocked due to the formation of a sand bar. The lowlands are allowed to absorb the floods as detention areas and release the burden of inundating urban areas and plantation areas. Flood bunds were constructed up along the river bank with a gate at Dodangoda to prevent water entering to paddy tracts during floods and gates were open to drain the catchment water during non flood periods.

2.1.7 IRRIGATION IN GIN GANGA BASIN

Irrigation Department maintained the irrigation projects in the basin for rainfed paddy cultivation. In 1919, flood control became a duty of the Irrigation Department under flood control ordinance. One benefit of the project was to protect paddy lands from floods. Hence the flood bunds were constructed at locations suitable to prevent floods. Basins in the left bank are as follows.

(1) Holuwagoda ela, which is the major tributary of Gin Ganga in the left bank, drains an area of 7000ha and joins the river at Wakwella (Fig.10). This sub basin has 1740ha of paddy lands. Irrigation work carried out by state improved the cropping conditions by constructing a series of anicuts (Fig. 10).

The first anicut constructed was at Bogahaduwa in 1954. It served an area of 95ha. Total extent of paddy was 1471ha (Brohier, 1954).

(2) Puhulduwa basin is the second tributary in the left bank next to Holuwagoda ela. This drains an area of 5500ha with the confluence near Walpita. Galagoda ela and Kimbi ela join together at Puhulduwa and named as Puhulduwa ela (Fig 6, Fig 7). Extent of paddy lands was 1398ha. in the year 1954.

(3) Ganegama Basin with 131 ha of paddy lands is in the left bank has 300ha drainage area and is adjacent to Puhulduwa. (Fig.2). Presently Ganegama pump house is located for this tract. 20 (4) Gothatuwa basin is with 53 ha of paddy lands. This basin drains lOOha and is

presently linked to Ganegama and the stream was closed in 1981.

Basins in the Right Bank are as follows.

(1) Majuwana basin with 128 ha paddy lands drains through Heen ela near Ganegama. (2) Dodangoda basin with 136ha of paddy lands meets the river near Dodangoda. It has a gate to control river floods.

(3) Kudawa Ganga basin with 1096ha paddy lands drains to Wakwella. Hegoda tract is a part of Kudawe tract but it is in the down stream. This part was partly drained to Kudawe Ganga.

These basins and tracts in the right bank are shown in Fig. 3. In Fig. 11 all three units are shown as Lower Gin basin. At present all three basins are joined to drain through Hegoda pump house.

The agricultural system protected by the Irrigation Department had protection bunds to avoid damages from a flow up to 500 cumec in Gin Ganga. It has been recorded that at Agaliya Station the flow depth is approximately 18.2ft (5.5m). The anicut schemes were improved one after the other to divert water from Holuwagoda ela to the paddy lots. In 1968 Holuwagoda Ela had 6 anicuts and Puhulduwa ela had 5 anicuts (Fig. 11). Upstream area has 4 anicuts. Hiyare reservoir was storing water from upper ela basin for Galle Town from 0.76ha catchment in Holuwagoda ela (Fig. 10). Any stagnation of water over five days killed the crop leaving patches of mud plains. However the aim of the anicut is to provide water during dry weather using base flow of the stream.

21 2.1.8 FLOOD CONTROL PLANS The Irrigation Department maintained the project under Irrigation Engineer -Galle Division up to 1971. Subsequently the Territorial Civil Engineering Organization (TCEO) was formed in 1971 and divisional offices were separated as Karapitiya, Baddegama, Hiniduma, Ambalangoda and Gintota regional offices. Anicut schemes were maintained under respective Divisional Offices. Gin Ganga flood control project was remained under authority of Irrigation Department. In 1948, a report was prepared by Kothari after investigations proposing a reservoir at Madugeta (Hensman, 1972). The idea of controlling the entire flood situation was studied and a feasibility report was submitted in September 1968 (ECIR, 1968). This report covered Kalu, Gin and Nilwala basins in the wet zone of Sri Lanka for multi-purpose development. The proposal included a diversion of water to Hambantota District from a Jasmine Maguru Reservoir through a transbasin canal diversion. Maguru Ganga was a tributary of Kaluganga, which has to be dammed along with Ginganga at Jasmine valley at river level of 16.6m to a height of 69.7m as the bund top level. The water thus collected was to be taken from a high-level trans-basin canal (Fig.2). The reduction in flooding can be compared with the river profiles shown in Fig. 12. These profiles were designed for the flood experienced in 1967. The flood bunds were proposed for closer width of the flood passage to reduce the loss of paddy lands and the profiles are calculated accordingly. The high flood levels are lowered by the storage capacity of the reservoir. Another option in this proposal was to have hydropower generation at Jasmine valley to release the tail water to Ginganga having the same bed level of river with an operating head of 54m. This was to avoid the flooding in the down stream valley. This will act as a multi purpose tank. The proposal put forth the possibility to control the floods during rainy season without an upstream reservoir. The 10 year without Jasmine dam river flood profile shown in Fig. 12 shows that the flood profile extends upstream of Mamina dola to Malamure ela basin with the flood bunds but without upstream reservoirs. As the local drainage occur in the tributary "ela" basins in the lower reaches of river, each sub basin needs to be isolated and provided with a pump with a lock gate facility to evacuate water on to the river. This arrangement necessitated pumps for following sub catchments as the flood bunds are higher than the paddy lands.

22 The streams chaining to Gin Ganga can be listed as below. Left bank streams

1. Holuwagoda Ela.

2. Keembi Ela - Puhulduwa ela.

3. Galagoda Puhulduwa Ela 4. Unanviti ela

5. Mamina Dola Right Bank streams 1. Kudawa Ganga

2. Halpatota Ela and Kudubiri Ela

3. Divithura Ela 4. Maben ela 5 Terun ela

6. Gonala ela 7. Malamure ela

When lock gates are used with elevated embankments then any river flow would not enter the tributary catchment. However trapped water has to be pumped onto the river to save the paddy crop. Possibility to pump Holuwagoda basin water within five days in the most efficient case is checked and shown for the flood of year 1967 (Fig. 10).

2.1.9 GINGANGA FLOOD REGULATION PLAN OF 1976

A Chinese Government Study Team made a plan in 1975 using many options given in ECI report (PDR, GRP, 1975). This new proposal selected the area downstream of Agaliya for flood protection (Fig. 13). The hydrological parameters of the proposal were based on the flood occurred in May 1969 for the drainage area to provide pumping. The worst flood affected area in 1969 was the stretch from Ginthota to Agaliya. In the proposal the flood was designed to pass between two embankment lines (Fig. 14). Existing high grounds were proposed to connect with earth embankments, raised up to 1.2m above the design water profile. The top width of the embankment was designed as 4m. In this project the flood passing Agaliya is to be directed to the sea by providing lowered bed levels. The lower Gin basin bounded by this set of embankments is divided into 11 drainage districts (Fig. 14). Holuwagoda

23 ela in the left bank was designed as a gravity drainage basin. Other 10 areas were equipped with electrical pumps to drain the water collected by its catchment. Lock gates are provided to facilitate gravity flow during non-flood periods. Rerouting Galagoda and Holuwagoda streams were the design options. When compared with the ECI plan, the Chinese Government plan introduced new changes in geography and stream morphology. Left bank drainage basins are marked as DL1 to DL5 while DR1 to DR6 basins are in the Right Bank (Fig. 14).

2.1.10 THE UNPROTECTED AREA OF LOWER GIN BASIN

Down stream boundary of any drainage district mentioned above is an embankment. Series of embankment lines (Fig. 14), which separated the drainage districts from the river on both sides, demarcate a space separated as unprotected for the passage of the flood. Despite the fact that Holuwagodaela drainage flow was taken off, flood level in this corridor has increased by 1.2m from normal level due to reduction in area of cross section of flow.

In the Chinese Government plan Galagoda ela water quickly reaches Telekada and receives no mixing from any source other than the river drainage. Ganegama area is not to be inundated due to closure of streams and rainwater is drained by a new canal and pumped to river at a lower location at Ganegama. Backwater effect is arrested from Agaliya to Gintota by lock gates. Parts of Divitura ela and Kimbi ela banks were raised, up to the designed level as those belong to unprotected area (Fig. 14). Upper reaches of both streams are experiencing added high level of floods. An embankment to protect Puhulduwa area (DL3) cuts off the river spillage at Baddegama.

Ten electric pump units protect the basins. Pump operators have to work day and night to control the flood in respective areas. Unprotected upstream basins are Maben Ela, Divithurai Ela, Gonala Ela and Malamure Ela in the RB. Unanviti ela, Mamina Dola and Nagoda Ela are in the left bank. These basins need relief protection work in the future either by an up stream reservoir or through a pump. The villages in the up stream areas were Unanvitiya, Nagoda, Keppetiyagoda, Mapalagama, Niyagama, Gonalagoda, Kahaduwa, Rekadahena, Agaliya, Gurusinghegoda, Ethkandura, Inimankada, Eramulla, Tanabaddegama, Pinikahana, Polgahawila, Horangalla,

24 Gammeddegoda (Fig.3, Fig. 4 & Fig. 6). The reason to omit these areas was the high cost per benefit ratio in providing pump houses.

A new bridge across river at Baddegama is to connect to join Hikkaduwa-Elpitiya road (Fig. 14). A ship lock is provided to pass any boat from Holuwagoda Basin to Main River when two water levels are maintained on either side of ship lock during floods at Wakwella (Fig. 14). New drainage canals were cut to join pump houses. Access roads are to be provided on bund tops. Seven bridges are to be constructed to link roads with main roads (Fig. 14). A drainage sluice is provided to drain water at Dodangoda. A pilot sluice is provided at Galagoda ela diversion point at Indurupatwila (Fig. 14). Separated sub basins prevent trans basin flow. The river flow at Agaliya is not interfering with sub basins if the gates are closed.

25 2.1.11 ENVIRONMENTAL ASSESSMENT METHODS

2.1.11.1 INTRODUCTION

The lack of environmental considerations in the planning of development projects could

result in severe impacts on the natural environment as happened before 1991, coupled

with the degradation of natural resources could be the impacts on the social and economic

structure of many communities. Therefore any development endeavour requires not only

the analysis of the need for such a project and the monetary cost- benefit involved, but

also an environmental impact assessment to look into the effect of the proposed

development project on the environment.

The environmental impact assessment (EIA) comprises of three sequential elements,

namely:

Identification

- description of the existing environmental system;

- determination of the components of the project.

Prediction

Identification of the environmental modification that may be significant;

Forecasting of the quantity and/or spatial dimention of change in the environment

identified;

Estimation of the probability that the impact will occur.

Evaluation

determination of the influence of cost and benefit to user groups and population

affected by the project;

Specification and comparison of the trade off (costs or effects being balanced)

between various alternatives.

Under each of the above elements, different methods of assessment are suitable, such as

Identification - Check list method

Environmental impact matrix

26 Predictive methods - Environmental information system

Modelling techniques

Scaling and measurement.

Evaluation- Environmental evaluation system

Essentially any EIA system must include at least the following steps ;

Preliiriinary activities to narrow down the scope of EIA studies

Description of the proposed project and of any reasonable alternatives;

Assessment of the likely effect of the project on the environmental, economic and social components indicating the nature of effects.

In this chapter, different techniques for environmental impact assessment are first briefly described and then some appropriate rapid methods for environmental impact identification and prediction are recommended considering the cost, manpower and time in developing countries.

2.1.11.2 TERMINOLOGY

In the process of studying the impacts on the environment of developmental activities, several terminologies are used in common (Lohani and Thanth, 1991):

- environmental baseline study (EBS)

environmental setting (ES)

environmental inventory (EI)

environmental identification (EI)

- ecological reconnaisance (ER)

initial environmental examination (IEE)

environmental impact investigation (EII)

- partial environmental impact assessment (PEIA)

environmental impact assessment (EIA)

- environmental appraisal (EA)

environmental assessment (EA)

- environmental impact evaluation (EIE)

environmental impact statements (EIS)

102 statements

27 although various terminologies are listed above have been used, most of them are used interchangiably. The commonly used terms in Asia are " Environment Inventory",

"Initial Environmental Examination", "Environmental Impact assessment",

"Environmental Profiles" and " Environmental Impact Statements".

"Environmental Inventory" is a complete description of the environment as it exists in an area where a particular proposed action is being considered. This serves as a basis for evaluating the potential impacts on the environment, both beneficial and adverse, of a proposed action. The term environmental baseline study, environmental setting or environmental identification could be considered as similar in scope as the environmental inventory.

Initial Environmental Examination is a preliminary assessment of environmental impact of a project and indicates those aspects which deserve further in-depth study. It provides only a cursory review of principal impacts and is therefore of more limited scope and depth than an Environmental Impact study. The term ecological reconnaisance, environmental impact investigation, partial EIA, Prehminary EIA, could be placed under the same category as the Initial Environmental Examination.

Environment Impact Assessment basically embodies the steps of prediction, scaling and significance interpretation, although many terms may be used to describe these particular steps. Thus most often the terms 'Environmental Assessment', 'Environmental Appraisal' and 'Environmental Impact Evaluation' have been interchangiably used with

'Environmental Impact Assessment'.

Finally the term 'Environmental Impact Statement' is a document written in specified format following a specific agency's guidelines. The EIS represents a summary of the

Environmental Inventory and the findings of the Environmental Assessment. EIS has also been referred to as 'Environmental Statements', 'Impact Statements', Environmental

Impact Reports' or '102 statements' in the USA..

28 2.1.11.3 ASSESSMENT METHODOLOGIES

A number of techniques have been developed for presentation of environmental impacts results to the decision makers and the general public ( Lohani & Thanth, 1991). These techniques can be listed as follows:

Ad hoc

- Check lists

Matrices

Overlay

Network

- Cost- Benefit Analysis, UNEP test models

- Simulation Modelling Workshops.

Detailed description of each item is given in the annex H.

2.1.11.4 ENVIRONMENTAL MONITORING SYSTEM IN SRI LANKA

The EIA and the environment protection licence (EPL) are tools to monitor the project activities through the central authority. This authority is delegated for small scale projects. The approving authority has the right to monitor the implemetation of the mitigating process. The public has the right to sue any violator in the individual basis.

Any non citizen has the right to complain against environmental damage from any proponent. The legal procedure needs time money and consultancy. The executive summary published by the proponent allows objections from the public with in one month and the approving agency shall consider all the points raised in that period. The already completed projects before the existance of the CEA have no control under this act. Only the new projects are covered by the Environmental Act. Since year 1995 environmental management system was improving in Sri Lanka with funds allocated for environmental monitorng and mitigating. Rehabilitation projects under Irrigation

Department had allocated provisions to look in to the environmental aspects of strengthening the staff and institutional development (IDAR, 1995). 2.1.11.5 ICID CHECK LIST

The International Commission on Irrigation and Drainage has published an environmental checklist. This list provides a systematic approach to find the environmental issues from project features for irrigation, drainage and flood control projects. The list provides method of analysis for planning, construction and operation and maintenance phases of those projects.

2.1.11.6 LEOPOLD MATRIX METHOD OF IDENTIFICATION

In practice if the issues are identified by observation the magnitude of the change can be rated by a scale of -5 to +5. The negative sign indicates a reduction or a loss. The positive sign indicates a gain or an addition. The significance of the issue is again rated in a 0-5 scale. The highest significance is 5 and the lowest is 1. No significance is given by zero.

The values for each activity is computed for each environmental issue. The results are shown in a row against the issue. The analysis is based on the matrix made of all these rows. The sign attached to the numerical value is related to the issue and it does not indicate good and bad of the issue (Canter, 1991).

2.1.11.7 DELPHI TECHNIQUE

EIA procedure usually get the help of experts for the identification of environmental issues and corresponding mitigatory measures. The team leader has the authority to select the best alternative plan with the mitigatory measures. The proponent and his wishes must be satisfied at all levels of planning. This technique rejects the extreme conditions and most acceptable solution is achieved to promote the proposal The expenditure is covered by the proponent. If one expert is involved in the investigation he has an advantage to listen to others and judge on his own way (Canter, 1991).

2.1.11.8 METHODOLOGY USED FOR PROJECTS IN SRILANKA

IEE and EIA are being prepared according to suitable methods which are in vogue.

Alternatives are compared by the same method or by any other method. The team selects the suitable method according to the nature of the project. The cost is borne by the project proponent. Methodologies used by different projects are in Table 2.2

30 Table 2.2 METHODOLOGIES ADOPTED FOR SOME PROJECTS IN

SRILANKA

NAME OF THE PROJECT TOOL FOR IMPACT IDENTIFICATION

IEE

1 Seethawaka Industrial Estate Questionnaire

2 Prawnculture project, Madilla Hap hazard manner

3 Dev. Of Beliduwa Islands, Kalutara Questionnaire

4 B/H cul. Cen. Muthurajawela Questionnaire

5 Industrial estate Kuruwita Questionnaire

6 Oil storage terminal, Sapugaskanda Check list

7 Wax match industry Matara Questionnaire

8 Kalmunai town dev. Project Checklist

EIA

9 Rajawella golf & hotel project Simple matrix

10 Samanalawewa wet blanketing Simple matrix/NW

11 Kerawalapitiya reclamation project Descrip. Statement

12 - Katunayake expressway Simple matrix

13 LPG import terminal, Muthurajawela Checklist

14 Industrial estate, Kalutara Scaled matrix

15 Relo.& moder. of tanneries-I/E Bata atha Checklist

16 Upper Kotmale Hydro power project Checklist/SEI

17 Sanitary land fill at Alupotawatta Scaled matrix

18 Wirawila walk inn Haphazard manner

19 SUVIC Hotel Project Seeduwa No

20 Aqua pearl villa, Bolgoda Checklist

21 Southern expressway Scaled matrix

22 Coal power plant Kalpitiya Checklist

23 Pelawatte golf & hotel Project Checklist

31 2.2 ENVIRONMENTAL ISSUES IN IRRIGATION AND FLOOD PROTECTION SCHEMES

2.2.1 Irrigation Projects Irrigation projects in Sri Lanka lead to several environmental issues when it is converting jungles in to rice fields. This includes physical processes of jungle clearing, canal cutting, earth moving, rock breaking, land leveling, inundating and reduction in down stream water supply. This creates disturbances and noise to people and animals during construction, destroys many trees and wild life settlements, creates new habitats, new residence, new employment, new cultivation etc. etc. The life span of most projects is considered as 20 years. Many projects on average yield about 2 ton/ha of paddy and these projects are those functioning for more than 20 years. Some projects affected by chemical action of command area are yielding still low production. Some parts of projects are abandoned due to salinity (Lower Dedduwa up to 80% by salinity). Sedimentation of the reservoir bed reduces the capacity of the reservoir (Kamburugamuwa Tank). Upstream land use had resulted in low base flow. Also the change of climate creates changes in the rainfall pattern. Bio diversity is reduced when frequent wetness is curtailed diversion schemes. Continuous inundation is said to favour bio diversity in the periphery of a reservoir after construction. The net result of the environmental changes may affect the value of the project. It needs proper care and rehabilitation to avoid any or further deterioration.

The down stream controlled projects such as flood control, inundation and salt water exclusion projects create so many problems in operation conditions. Efficiency of operation is linked with financial expenditure and hence many projects in wet zone of Sri Lanka are abandoned or under the threat of abandonment. Specially, diesel pumps used to protect paddy lands in Mihiripenne, Benthota schemes were abandoned due to high cost. Pannala pump house in Bingiriya area was serving well for a few decades but now it is abandoned. Electrical pumps used to evacuate water are better than diesel pumps due to its low maintenance cost. Nilwala project had 15 pumps to evacuate floods but only one was in operation in 1999. Rising spare parts and fuel costs often threatens the successfulness of a project. It is said that electrical pumps in GRP are operating at 50 % success level due to the need for better repairs. Lift irrigation

32 project in Rajangane, which uses suction pumps is now abandoned. Farmers abandoned the Mahiyangane-Nagadeepa lift irrigation project, and the reasons are stated as high cost of operation and lack of motivation.

Salt-water exclusion projects are abandoned due to low income from paddy cultivation in the last two decades. Acid sulfate development in Nilwala project was reported first time in Sri Lanka in 1988. This was due to low flushing effect created by the flood control in Nilwala project. Excessive concentration of iron and aluminium ions created by pyrite oxidation is said to have increased the acidity of the soil (Weerasinghe, 1993). Social processes are important to gauge the success of the irrigation project. Farmers are the main stakeholders of an irrigation project. If the public desire to work in paddy land is lost then the sustenance of a project is lost. Terrorist activities have created a dangerous environment either by chasing the farmers or killing village folk. Jungle clearing for irrigation has the habitat of elephants and as a result they rampage the villages in search of food in Moneragala, Matale and Puttalam Districts. Some elephants even damage irrigation structures.

Irrigation projects have either identified or experienced many positive and negative environmental issues. These are experienced and listed either by farmers, general public, officials or experts. The following (Table 2.1) shows a list of such issues that had been found in few irrigation schemes extracted from available reports.

33 2.2.2 DIFFERENT CATEGORIES

In order to collect the environmental issues of irrigation projects, experience gained and published in various articles and reports were collected. It was also important to collect the features of other water-related projects operated by many agencies in state sector. Environmental features are mainly due to physical processes. Social processes have also contributed to many environmental problems. Economic conditions have a greater component for the sustainability of any project in the long run. Many areas are abandoned if the crop is not profitable. Often the state had provided subsidies to mitigate the impacts of many projects. Environmental indicators seriously considered in many projects or events are summarized below. (1) General

Low crop yield in many projects is due to poor drainage and subsequent increase of hardness. Crop damage is mostly due to late land preparation, which exposes the crop. Crop damage is also due to wrong fertilizer and growth of pests. Use of weedicide is polluting watercourses and drains. Some damage is due to wetness in the harvest of paddy. BOD build up in water is due to land clearing. Salinity build up is found in command area where saline water levels fluctuate. Most lowlands are abandoned because of high acid sulfate in soil. Malaria and fluorosis are endemic diseases, which are found in most irrigation schemes.

2) Coastal Lowlands Failure in controlling up tides in gated control units and gradual spill of saline water into coastal lakes in the dry months causes this effect. Sand niining and lowering of riverbed is also said to cause salinity intrusion.

3) Groundwater pumping Excessive groundwater pumping has lowered storage and operation is beyond the safe yield level in many irrigation schemes. In Jaffna and Mannar, aquifers are polluted by activities such as accumulation of contaminants and salinity due to excessive pumping. 4) River pollution River pollution has caused due to addition of vegetative matter and chemicals to water in excessive quantities.

34 5) Drinking water quality

Increased population needs more water. Usually intakes are from rivers and reservoirs. Hardness is in dry zone water with excess fluoride. Dissolved silica is causing diseases (Mahiyangane), Salinity is mixed with low flows in dry periods (Galle).

6) Spread of mosquitoes

Abandoned gem pits, abandoned water wells, coastal marshes, stagnant water, livestock farming and hot climate promote mosquitoes. Failure of control measures due to terrorism and lack of medicines to cure malaria is causing high incidence of malaria. Resistance is developing against chemicals by mosquitoes. Use of electrical lamps in houses and high temperature of asbestos roofed houses in most irrigation schemes attracts mosquitoes. Cluster houses assist spread of diseases in both zones.

7) Diseases

Infected persons in schemes bathe in streams. Sewage enters streams. People use stream water directly without boiling, travelers also transfer the diseases, piggery and stray animals lead to encepalitis spread, low- quality food distribution in boutiques causes diseases. These cause spread of disease and dysentery. Encepalitis is common in wet zone. Lepto-spirosis is common in wet zone.

8) Bank erosion

Increased demand for river sand has increased sand mining, and lead to riverbank collapse.

9) Flood control projects

Abandoning of paddy lands due to low income, soil subsidence in protected lands, reduction in ground water quantity, reduction in fish growth, and high evaporation conditions are prominent in flood control projects such as Gin and Nilwala in wet zone.

10) Aquaculture

More lands are lost to salinity in artificial fishponds. Bio diversity is affected by artificial treatment methods. Some fish varieties are threatened to extinct. This is seen mostly in Puttalam area. 11) Sedimentation

Upland cropping in bad manner and improper clearing of lands has led to sedimentation of many reservoirs. Rainfall naturally causes sedimentation in tanks.

12) Reptiles

35 People die due to venomous attacks and crocodile bites. Young reptiles migrate to water passages in development schemes. This is a common issue in dry zone and Nilwala scheme.

2.2.3 MITIGATORY MEASURES FOR ENVIRONMENTAL ISSUES

Many development projects linked to irrigation and flood mitigation are maintained by state and the feed back from people is always looked forward for the success of the projects. Experts in local and foreign agencies advise the state for suitable actions.

Projects are planned after careful analysis depending on the budget. Some mitigatory measures proposed for some projects are listed below.

1) Law enforcement and awareness programs to reduce environmental degradation can reduce human component of environmental activity. Municipal taxes, Environmental protection licenses are some such measures.

2) Garbage removal and dumping to reduce water quality degradation is needed.

3) Controls in burning of forests to prevent water pollution are needed. 4) Reduction in highland erosion to prevent loss of topsoil via suitable terracing of land and construction of stone- walls.

5) Control of mosquito breeding grounds to reduce infections. 6) Use of good quality water for drinking to reduce poor health conditions.

7) Control of salinity intrusion to prevent degradation of land.

2.2.4 ENVIRONMENTAL ISSUES IDENTIFIED IN EIA REPORTS OF IRRIGATION PROJECTS Irrigation Department had proposed the following projects and prepared the EIA for the approval of the Central Environment Authority during the last 10 years. EIA was not performed for already approved projects but the law was effective for any major project under consideration. Minor projects are considered for IEE by the CEA and the EPL was issued after approval.

The issues from irrigation projects listed below were studied

36 1) Diversion of Mau Ara to Malala ara- Hambanthota District 2) Restoration of three tanks in Moneragala District 3) Diversion of Weli Oya in Moneragala District

4) Restoration of five tanks in Polonnaruwa District

5) Neelabemma Project - basin- Puttalam District

2.2.4.1 Diversion of Mau Ara to Malala Ara in Hambanthota District This project supply water to tanks under Malala Ara and the environmental issues identified are as follows (EIA Mau Ara, 1997).

• Poverty among villagers- prevailing condition

• Water shortage- for any purpose

• Lack of infrastructure development- villages are not developed

2.2.4.2 Restoration of Sugala Devi tank in Moneragala District

Some tanks in the jungles of Moneragala district had been abandoned for nearly 700 years. One of the tanks selected for restoration is presently supporting a village. The environmental issues studied under this tank are given below (EIA Sugaladevi, 1997).

Issues in Hydrology

• Changes in the yield pattern - with more water

• Flooding is reduced- with new storage

• Raising of the water table around the reservoir

Issues linked to Soils o Soil erosion

• Sedimentation of reservoir due to new development

Ecological

• Floristic diversity

© Faunal diversity due to new activities

Socio-economic

• Disruption of social fabric by outsiders

• New diseases

• Loss of forest use

37 • New business community-settlers & buyers

o Short term employment

• Better nutrition

• Better roads

2.2.4.3 Diversion of Weli Oya for Sittaram Palata Poverty Alleviation in Moneragala District The Impacts on Environment Weli oya is a tributary to and it is diverted for feeding village tanks. The environmental issues are discussed in the report. Following are the issues discussed under the project analysis (EIA, Weli oya, 1997).

Issues in Physical processes

• Soil erosion and siltation- due to new crops

• Reduction of run off for down stream areas

• Danger of canal spilling

• Noise and air pollution due to construction

• Rising of ground water table due to storage

• Reduction in soil erosion by new methods

Issues in Biological processes

• Obstruction to fish migration because of anicut

• Impact on wild life due to settlements

• Loss of forest cover due to jungle clearing

• Good impact on bio environment due to increased wetness

• Increase in bio diversity

• Increase in plant growth by high ground water table

• Reforestation due to motivation

Issues in Socio-economic processes

• Water availability for bio mass improvement

38 • Loss of highlands due to canal construction, reservation

• Increased cultivation for both seasons

• Conflicts in land benefits-initial planning

• Land encroachments

• Cattle farms creating conflict development

• Employment benefits

• High income

• Infrastructure development

• Improved living conditions

• Developments in the communication network

• New access to the other side of

• Safe drinking water

• Health facilities from new hospitals

• Better education infrastructure for children

• Investment from outside

• High productivity

• Reduction in capital drain

• Better water management

2.2.4.4 Restoration of five tanks in Polonnaruwa District Polonnaruwa area, closer to is under the dry zone and this abandoned area in Medirigiriya seat is closer to terrorist area. The lands are suitable for rice cultivation but terrorism is a social threat which will destruct civilized day to day life in the area. Irrigation schemes usually possess a set of qualities which are environment friendly and can be compared by other projects.

The tanks selected for the development are abandoned for nearly 700 years and were in the jungle. Restoration will provide better facilities for people. The environmental issues identified are as indicated below (EIA Polonnaruwa, 1997). Tanks under this project:

1) Kudumbiya wewa,

2) Rota wewa

3) Aluth Wankanda wewa

39 4) Maha Halmillewa wewa 5) Gamini Pura wewa Environrnental issues are identified as follows

• Degradation of borrow areas

• Soil erosion after jungle clearing

• Silting from abandoned borrow areas

• Base flow alteration

• Elevation of ground water table

• Salinity build up due to water use

• Jungle losses

• Impact on wild life

• Wet land formation

• Breeding of mosquitoes

• Conflict between man and elephant

• Reduction in

o More damage to the jungle in the long run

• Increase of income from cultivation

• Community development from economic enhancement

• Improved fishery in tanks

• Social status escalation

2.2.4.5 Neelabemma Project in Puttalam District This project is supplying water to 1000 acres under lift irrigation and 1000 acres under gravity irrigation from Kala Oya through a diversion canal.

The environmental issues are wild life interference and human settlements. Elephants were deflected by a live electric fence. Political interference and encroachments were disturbing land tenure. Water quality is affected due to heavy return flows from upstream tanks. Malaria is endemic in the area. Jungle clearing is affecting the land degradation (EIA, Neelabemma, 1992).

40 2.2.5 FLOOD PROTECTION PROJECTS 2.2.5.1 Nilwala Flood Control Project The project, which is in Matara District protects the area from Akuressa to Matara. The flood bunds on either side of the river direct the flood to the sea. Trapped water in the sub basins is pumped in to the river using diesel pumps at Kadawedduwa and Bandattara. The identified environmental issues are listed as follows. 1) Development of acidity in the paddy tracts 2) Land subsidence in the basin 3) Water shortage for paddy crop. 4) Partial completion of the project

2.2.3.2 Keleni Flood Protection Scheme Kelani flood protection scheme in Colombo and Gampaha districts is to protect lower basin by flood bunds. The Right Bank area is at a higher level and this flood bund protected RB area without a drainage problem. The left bank has a bend with scouring effect. Trapped local drainage is pumped into the river. There are 22 pump houses and a passage for direct run off. The sections crossing the bund for rail and road are temporarily closed at high floods. Hanwella river stage is monitored for controlling. The identified environmental issues are,

1) Sand mining in the river. 2) Pollution in river due to industries. 3) Encroachers fill the land in the flood corridor.

4) Low flows due to upstream flood control reservoirs 5) Water is taking for safe drinking at Ambatale.

2.2.5.3 Bentara Flood Protection Scheme This scheme in Galle District protects Dedduwa Rantotuwila area by flood bunds using a control gate. The trapped water is pumped in to the river to save the crop. Many areas are abandoned due to low income from paddy. Reeds were cultivated in some area due to salinity. Diesel pumps were gradually removed due to its high cost in pumping. Salinity controlling flap gates were introduced at some streams but it was not continuing. The Irrigation Department prepared these reports through experts and attended the

41 requirements to go ahead with the construction work of such projects as the implementing authority. The identified environmental issues are,

• Salinity intrusion into lowlands

• Abandoning the cultivation

• Low income from paddy

42 Table 2.1 ENVIRONMENTAL ISSUES IN PROJECTS OF IRRIGATION DEPARTMENT

Negative effects are noted in the table with x-ve sign

ENVIRONMENTAL ISSUE PROJECT 1 2

1 Changes in yield patterns

2 Canal spilling x- 3 Reduction in flooding x X 4 Reduction in run off x- X-

5 Rising of water table X 6 Soil erosion X- 7 Sedimentation X- X- X-

8 Salinity X- X-

9 Floristic diversity X

10 Faunal diversity X

11 Disruption of social fabric X- 12 New diseases X-

13Loss of forest X- X- X- 14 New business crowd X X X 15 Long term benefits X X X X 16 Short term employment X X X X

17 Better nutrition X X X X 18 Better roads X X X X 19 Noise and air pollution X- 20 Impact on wild life x- X- X- X- X- 21 Increased cultivation X X X X X 22 Land conflicts X- X- X- X- 23 Infrastructure development X X X X

24 Health X X X X 25 Education X X X X

Source of information EIA EIA EIA EIA EEE IDR IDR IDR

NOTE: The names of the projects are as follows. The issues were taken from study of the projects. 1) Sugala devi tank restoration 2) Diversion ofWeli oya 3) Restoration of 5 tanks in Polonnaruwa 4) Diversion of Mau Ara 5) Neelabemma Project 6) Nilwala Scheme 7) Kelaniya Scheme 8) Bentara Scheme. Adverse effects are marked as x-

The issues are extracted from Environmental impact assessments (EIA/TEE), or Irrigation Department reports (IDR). 2.3 ENVIRONMENTAL ISSUES OF GINGANGA REGULATION PROJECT

2.3.1 General

The method used for the identification of environmental issues is discussed below. Scientific data were collected from those institutions, which processed and preserved data in respective institutions. The Department of Meteorology, Department of Irrigation, Geological Survey of Sri Lanka, Survey Department, Port Commission, Department of Coast Conservation, The National Aquatic Research Agency, National Building Research Organization and many other private sector agencies were contacted to acquire information. Some of the information is from those published in the accepted journal volumes. The Irrigation Department publishes separate feasibility reports for each project. EIA reports are available since year 1980. The Wild Life Department and The Forest Department maintain, flora and fauna records. The administrative departments, The Social Services Department, the Central Bank, the Census and statistics Department, the Health Services Department, Engineering Departments, Provincial Authorities and the Education Department maintain some social and economic data for the project.

Specific issues are published in newspapers. Specific organizations collect the data pertaining to each issue and subsequently publish those findings in journals. Hence literature available in data form supplies basic information. These data are available for reference and some are supplied on request. Some Departments destroy data after five years (Kachcheris). Some departments have no storage capacity. Negligence of officers resulted in data loss. Some results of hydro logic data have to be verified from near by stations. Delay in payment of damages to flood victims does not show the time of occurrence.

Field visits and inspection of sites had been the most successful way of collecting data. This showed the present condition of the project. Several visits proved a better recognition of seasonal changes. The narration by stakeholders, individually and collectively give many reliable data but their motivations are either exaggerated or censored. The questionnaire survey used for this was fruitful to obtain a balanced view of many but political directions had also

44 been forwarded with a hidden motivation in mind. Decades ago a politician is said to have distributed lands around his interested area so that, the farmers shall be a barrier against wild animals.

Scientific data were obtained from several sources. ECI report (ECIR, 1968) supplies some information up to year 1972. Hydrological data is collected from hydrological annual (HA, ID) and river gauging records of Department of Irrigation. Newspaper reports provided public comments. Letters of requests were sent to Divisional Secretaries, District Secretaries, Irrigation Engineers and their officers, Deputy Director of Irrigation, Medical Officers, Agrarian Services Commissioner and his officers to obtain assistance to data collection. Reports produced by the ID for rehabilitation feasibility of NIRP were studied. Annual reports discussed at the District Coordinating Committee are studied. The selected committee to investigate current issues of GRP in 1997 headed by Mr. Bulumulle discussed the problems in irrigation and water supply. A copy of the recommendations presented by Divisional Secretary Baddegama to the Bulumulle Committee was collected. Completion report of GRP by Chinese Team in 1983 provided concluding remarks of GRP.

The hydrological data provided information about the Gin Ganga maximum flood hydrograph. Depth-Area-Duration curves are prepared for Gin basin using the recorded storms in 1940,1944,1947 and others recorded at Udugama rain gauge and the designed storm for 20 year return period is selected as that occurred in December 1967 (ECIR, 1968). The Chinese Government Plan for flood mitigation was designed for May 1969 storm and the area under flood protection was 5000 ha. The area from Mapalagama to Agaliya was excluded. The flooding issue of this area was technically aggravated due to back water effect of 1.2 m in addition to the level prevailed at Agaliya before 1983. However sand mining in river reduced the time of concentration of floods. The backwater effect has its effect for 11 km upstream of the river from Agaliya.

45 2.3.2 PLAN OF FLOOD CONTROL A Chinese government assistance was obtained to prepare a plan for flood control in the Gin Ganga basin (Chinese Team Report, 1975). The designers from Irrigation Institute of Hunan Province - China considered four options for the flood control project of Gin basin. (1) Constructing reservoir upstream and providing bunds for down stream (2) No reservoir in upstream, diversion of flood downstream (3) No reservoir in upstream and rerouting the main stream at downstream location (4) No reservoir in upstream, construction of bunds in downstream and rerouting streams. The fourth option was selected after planning for wider flood passage. The decisions reached as final targets after investigations were as follows.

1 Reduce flooding in lower basin to allow early cultivation according to season, (irrigation facility is not considered) 2 To direct the runoff from Agaliya to Ginthota without interfering with the lower basin, (designed for 20 year flood) 3 Pump water collected in the lower basin if gravity flow is not possible (designed for 10 year flood).

4 Upstream area from Agaliya has no formal expenditure for any development. 5 Unprotected area is to be declared as unsafe and residents to be removed and compensated.

6 Divitura marshy lands were planned to reclaim under the project.

2.3.3 TARGETS OF CHINESE GOVERNMENT PROPOSAL

The targets of the executed project as given in the Chinese Government proposal could be listed as follows (GRP, PDR, 1976).

The need for the flood protection was studied after surveying the lower basin from Mapalagama to Gintota, to identify the most suitable area for protected paddy cultivation. The targets included solutions to environmental problems identified in the preliminary surveys done by Chinese Team. This program reduced the project area mentioned in ECI report. Area upstream of Agaliya was not taken for sub basin protection.

46 1 Protection of 4100 ha of lowland paddy and 1200ha exports crops in low-lying area (Fig 14). Flooding of agriculture was the main environmental issue.

2 Protection for 4000 houses and 21000 persons in Karandeniya, Baddegama, Bope Poddala and Ambalangoda Divisional Secretary Divisions (Fig 6). Inundation of houses was the environmental issue.

3 Baddegama, Dodangoda, Majuwana, Hegoda, Ginimellagaha, and Gonapinuwala areas are to be protected from floods (Fig 14). Environmental issues were low demand for investments in infrastructure development.

4 Construction of an improved road network in the project area for transport purposes (Fig 24). 24 km of gravel roads was planned along the flood bunds. Improvement of existing gravel roads to main road level in Hegoda basin was planned. 4km of major roads with a new bridge across river were planned (Fig 24). Environmental issue was low accessibility in the area.

5 Extension of electricity service to under-serviced areas. Environmental issue was the low infrastructure development.

6 Improved cropping intensity to improve income by raising crop yield from 20 to 50 bushels per acre (1 to 2.5 ton/ ha) in the project area. Environmental issue was low income from rice crop.

7 Improved land use and land value. Environmental issues were the low land use and value.

8 Reduction in subsidies allocated for flood relief and rehabilitation. Environmental issues were property damage deterioration of health due to pool of stagnant water.

9 Reduce damage from trans basin flow from Halpathota to Gonapinuwala, Hegoda and Baddegama to Kimbi ela. This environmental issue to be mitigated was the target.

10 Construction of a shiplock. Target was to provide uninterrupted transport along river.

47 2.3.4 PRE PROJECT ENVIRONMENTAL ISSUES

2.3.4.1 ECI report, Three basins Project, 1968 This report listed and analyzed the details of environmental issues of Gin Basin for the protection works proposed by it. These are as listed below.

1 Property loss,

Flooding in the lower Gin basin causes damages to paddy crop (Fig 28). Flood damages the houses constructed in plane areas. Floods are damaging roads, concrete and timber posts erected near the roadways for cable lines.

2 Loss of yield from paddy, Excessive floods always reduce crop yield. Heavy rain causes physical damage to the plants. In addition, inundation by floods cause shedding and kills the plant. Loose soil layers float and shift to another locations, resulting crop damage.

3 Loss of income from cash crops, Tea lands are affected by floods and the tea plant dies after 5 days of inundation. Floods also affect sugarcane cultivation. Rubber and cinnamon crops are not showing excessive damage due to floods (Fig 22). Highlands adjoining most wetlands are suitable for tea crops.

4 Heavy flood damage expenditure, In 1968 an expenditure of Rs 0.12m was incurred as compensation to flood victims of Gin basin. The social services department is paying compensation to flood victims. Loss of property claims up to Rs. 1200 was paid for each house owner. Food items were distributed and temporary lodging is provided.

5 Saline wetlands, Salinity intrusion due to cutting of sand bar 5 times a year to clear Mahamodera out fall is noted. The opened out fall allows seawater to come into the canal due to low flow in the canal.

6 Jasmine and Maguru dams, It shows the suitability of tectonic and geologic features to locate the dams and anicuts, Storage of water and power generation are possible at this location. 7 Soil fertility and crop yield, A record of analysis of crop yield shows that the yield is averaging to 20 to 40 bushels per acre. The reason for low yield is the wetness of the area and low temperature. Soil

48 fertility is also at a lower level in the traditional lands. Silt deposits from floods make the fertility of the land. Flood evacuation will reduce land fertility. This area had low crop yields.

8 Water profile and design height of bunds, The design showed that nearly 1.2 m of the level is raised if the run off is controlled with in the flood bunds. This will raise the embankment line below Agaliya and pumps are needed to evacuate water in this lower basin. Flood control imposes land barriers. Cost of operation and maintenance of pumps is an environmental issue.

9 Some paddy lands of Holuwagoda tract, which needs flood evacuation, Nearly 2000 acres are cultivated below the 0.6m-contour of mean sea level in the Holuwagoda tract. This area is linked with the river at Wakwella. The report proposed a pump to evacuate drainage storage of this basin and it will protect 4000 acres. The issue is flooding in this low land but difficulty is due to its very low elevation in the near sea level. Land use in this basin is limited for paddy only.

10 Low benefit cost ratio of flood protection, The ECI report shows that the benefit obtained by flood evacuation is not reflected in old areas of agricultural production. Maben ela and Divitura ela have 2000 acres of marshy areas, which can be developed into paddy lands. Other facilities are given for old cultivated lands to develop security against crop failure from floods. Additional profit can be gained by fertilizer use but it will be very little. Hence benefit of flood protection is not accounted only in economic terms.

11 Transportation difficulties, Transportation difficulties are common in the basin. Road damage and marooning is a great obstruction to the travelers. Traffic restrictions isolate the area and development is handicapped. There is no proper road transport system in the flood basin of Hegoda, Telikada and Wakwella during floods. Bus services are curtailed and individuals deploy boats.

12 Relief duties during floods, People need relief work during flood time and hence state has to supply food and lodging to victims. Besides people are ready to vacate the houses and to move to safe areas. Social service officers under Government Agent investigate the immediately needed assistance and evacuate people from the worst affected area to public places in Baddegama and Bope Poddala divisions. Warning about the impending disasters is

49 being announced through loud speakers. Immediate assistance will be given early. Compensation for damages has to be extended after floods. 13 Difficulties in manual gate operation works,

Kepu ela and Dodangoda gates were manually operated. The manual operation system in 1973 used to flood protection had many difficulties in carrying out physical control work. Operators of gate face transport problems. Hence in future motor driven gates are more suitable and versatile.

Summary Environmental issues due to flooding were identified as of various nature. 1 Flood inundation in the lower basin. 2 Damage of rice crops. 3 Damage to house and livestock property.

4 Damages to roads and foundation of posts and services. 5 Closure of schools and children not attending schools.

6 Well water deterioration.

7 Difficulty to carry out permanent construction in flood prone areas. 8 Reduction in industrial activities using clay and brick.

9 Inundation of tea lands leading to root rotting.

10 Trans basin flow. 11 Drainage from tributary streams is delayed by upstream river flow (back water effect).

12 River flow provides recharge of bank storage. 13 Inundation provides soil nourishment from silt deposition. 14 Inland fish breeding grounds are naturally maintain by floods. 15 Uplift forces destabilize the earth alluvium.

50 2.3.5 POST PROJECT ISSUES

2.3.5.1 CHINESE TEAM REPORT-(Completion Report, 1983)

Only the down stream control methods were adapted by Chinese Design for 10 drainage districts. Galagoda ela is diverted. Holuwagoda ela is separated from the river. The completion report gives the details of all construction works. It also shows the importance of maintenance necessary for bunds and canals. Important points for the maintenance work are given in this report.

(1) 35 km long drainage canals need frequent desilting

The drainage water designed to flow down the net work of canals and will not flow smoothly if frequent desilting is not done. The environmental issue is the possible canal block.

(2) 24 km embankment lines need mud grouting and cutting of termite hills

The embankment lines are subjected to slipping and cracking due to its weak foundation condition on peat soils. Hence mud grouting has recommended for strengthening by

Chinese Team. Environmental issue is the breaching of bunds, which will cause disasters if any weak point is developed in the line of bunds.

(3) 7 bridges need foundation protections

It is recommended to protect against sand mining in river, which is disturbing the foundation of bridges. Environmental issue is the damages to bridges.

(4) Back water effect up to 11 km upstream of Agaliya with heavy inundation effects upto 6 km. It has an impact on the paddy lands and roadways in Unanvitiya, Welivitiya,

Pogahawila (Fig 3). This was mentioned to take preventive measures against likely damages for roads and crops.

(5) Mehimulla pump house has the facility of irrigation from river water. This is using the same pump in the reverse direction and lifting water to a high out let. This is not taken for operation. This is addressing an issue in water shortage.

(6) Protection of electrical lines and maintenance

The target of the electrical supply lines is to use it for further expansion of the distribution

51 system for the benefit of villagers. However the report recommends not to use it for any other purpose as it will disturb the services. Flood control operation in protected basins depends on the power supply and hence any failure will badly reflect on crop yield. Only pumps are affected by power failure and flood protection is the environmental issue concerned under this. Any lapse in these options will result in low efficiency of the project.

2.3.5.2 BULUMULLE COMMITTEE REPORT 1997. A committee was appointed by the Government in 1996 to study and report about the achievements and deficiencies of the Gin Ganga Regulation Project and to recommend remedial measures necessary for the identified problems. It was identified as Bulumulle

Committee Report, 1997. Government appointed this committee as many farmers abandoned paddy lands since 1992 and left as fallow. Though politicians were interested to correct short- comings funds were not available even for the desilting recommended in the Chinese report. This committee collected information from Divisional Secretaries, farmers and state officials, etc. from the project area. Farmers presented their grievances and necessary solutions for irrigation difficulties. Many of these presentations reflect on environmental issues of GRP.

Identified problems in the system are listed as follows.

1) There had been no desilting done from 1983 along the canals of GRP.

Rehabilitation and desilting is necessary for the length of 35 km.

Water- logging in paddy lands is the environmental issue.

2) Low level of maintenance of canals, spills and culverts has affected the cultivation negatively in all drainage areas. Lack of efficiency in canals.

Water- logging in paddy lands is the environmental issue.

3) Stagnation of water in Hegoda, Holuwagoda tracts.

Water- logging in paddy lands is the environmental issue.

4) Inefficiency in pump operation

This leads to water- logging.

5) Lack of minor tank systems to store water for irrigation.

Crop failing due to water shortage is the environmental issue.

•52 6) Lowering of groundwater table due to rapid flow and also due to lowered riverbed.

Reduction in groundwater quantity is the environmental issue.

7) Salt water intrusion and thus, reduction in drinking water.

Salinity intrusion is the environmental issue.

8) Farmer organizations are not functioning in the project area. This is a social issue.

9) Lack of coordination to solve farmer problems among departments. This is a social issue.

10) Inundation of upstream areas of the project due to down stream development work.

New environmental difficulties in water- logging has resulted

11) Irrigation system is not successful during droughts. Water shortage for crops is the environmental issue.

The report presents the status quo and suggests possible corrective measures. As this report collected views from farmers it shows irrigation staff atrocity, which had occurred as a result of lack of funds. The benefit acquired by farmers of pumped basins is not replicated to major Holuwagoda tract and farmers needed state assistance for flood evacuation. Further there is no supply of water in the form of diversion canals or upstream reservoirs in the sub basins. Environmental changes are reported as a problem for irrigation. Hence this report lists many environmental issues newly created by the project as given above.

Table 2 summarizes environmental issues obtained from literature for pre-project and post project conditions.

53 Table 2 a. SUMMARY OF ENVIRONMENTAL ISSUES OBTAINED FROM LITERATURE

PRE PROJECT ISSUES POST PROJECT ISSUES

Flooding in the lower basin which was Beyond Mapalagama Flooding restricted to unprotected area and lower (ECI report) Holuwagoda ela basin and Divitura upper basin and upto Agaliya from Mapalagama (Chinese team report, 1983)

Trans basin flow from Baddegama to Kimbi ela Halpathota to Gonapinuwala (ECI and Chinese team Reports) Trans basin flow prevented in 1983 (Chinese team report)

Soil fertility enhancement in the flood basin (Other reports) Soil fertility enhancement prevented in 10 basins Partly prevented in Holuwagoda basin. (Chinese team report)

Salinity in Kudawe basin, Holuwagoda basin In dry periods (experience in water supply at Wakwella) Salinity in Kudawe basin is reduced by bunds. Salinity is limited to Kepu ela and river bed and it will improve due to dry weather (Bulumulle report)

Floods damage agricultural crops- rice, vegetables and tea (ECI report) Crop damage in 10 basins is stopped (Chinese team report)

Flood damage to roads at inundated sites (ECI report) Protected area will protect the road crossings (Chinese, Bulumulle reports)

Power lines and telecommunication lines are damaged by floods (ECI report) Foundation damage reduced (Chinese team report)

Floods caused access difficulties and disrupt school attendance of students and staff. (Other reports) Unprotected area access is not good Protected area has good and safe accessibility. (Chinese team report)

Floods inundate wells and reduce safe drinking water and water quality. Flush out all chemicals (ECI/ Chinese/ Other reports) Improve safe drinking water area in lower basin. (Chinese team report)

54 Table 2 b. SUMMARY OF ENVIRONMENTAL ISSUES OBTAINED FROM LITERATURE

PRE PROJECT ISSUES POST PROJECT ISSUES

Flood areas were not used to construct permanent houses (Other reports) Permanent houses constructed (Chinese team report)

Floods reduce clay products in the lower basin (Other reports) Industries improve in lower basin (Chinese team reports)

Floods reduce crop growth period and delay the land preparation and crop planting (ECI report) No delay in planting. Unprotected area is not productive

Lowlands were neglected without development (Land use map of ECI report) Part of Divitura and Kudawe is reclaimed (Chinese team report)

Kepu ela 300 ha only was good in 1972 (topo map, 1972, Brohier, 1954) Kepu ela expected to be good (Chinese team report)

Difficulty in draining below Opatha anicut at all times. (Chinese, ECI reports) Same effect to a lesser extent (Chinese team report)

Road improvement weak in lower basin (ECI report) Roads expected to improve (Chinese team report)

Flood victims were paid Rs 2000 for damages and relief measures were needed (ECI report) Less victims (Chinese team report)

Kumme area was less developed due to trans basin flow (Other reports) Kumme area will be developed (GRP)

Holuwagoda has only one season per year (Other reports) Two crops will be possible (GRP)

Yield was 20-40 bushels per acre (ECI report) Yield expected to be doubled 40-80 bushels per acre (Chinese team report)

Drought areas increase/aggravate under flood control (ECI report) Same effect recorded (ECI, Bulumulle)

Soil fertility was due to silt deposits (Other reports) Silt load will be directed to sea from Agaliya downwards (GRP)

Salinity along river and Kepuela reached Wakwella, Kudawe area (GRP reports) Kudawe is protected (GRP) and bed level lowered

55 Table 2 c. SUMMARY OF ENVIRONMENTAL ISSUES OBTAINED FROM LITERATURE

PRE PROJECT ISSUES POST PROJECT ISSUES

Increased salinity (Bulumulle)

Maintenance difficulties in canals (Bulumulle)

Reduction in land use (Bulumulle)

Water- logging in lands and soil subsidence (Bulumulle)

Ground water quantity reduction (Bulumulle)

Surface water quantity reduction (Bulumulle)

River bank erosion (Bulumulle)

Reduction in drinking water to town supply during dry periods by salinity (Bulumulle)

Low income from crops and farmers are not organized for remedial proposals (Bulumulle)

Land use was for one season in paddy but upstream areas had two seasons and marshy areas had no cultivation (Other reports) Area improved for Yala and Maha in new lands of Divitura and other basins (GRP) Land use was reduced as fallow (Bulumulle)

Water- logging and drought reduced cropping (Bulumulle)

Upstream area inundation due to downstream reclamation (Bulumulle)

Difficulties in manual operations in lock gates (ECI report) Newly installed electrical pumps are easy to operate (Chinese report)

Pre project issues are listed on the left half of the paper and the corresponding development is noted in the right half of the paper.

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