A relatively less polluted drinking water reservoir of metropolitan istanbul near the black sea coast

e

Wat. Sci. Sci. Tech. Tech. Vol. Vol. 39, 39, No.8, No. 8, pp. pp. 147-153, 147-153, 1999 1999 Waf.

Pergamon Pergamon

0 1999 IAWQ <©19991AWQ Published Published by by Elsevier Elsevier Science Science Ltd Ltd Printed inin Great Great Britain. Britain. All All rights rights reserved reserved Printed 0273-1223/99 $20.00 0273%1223/99 $20.00 +t 0.00 0.00

PII: S0273-1223(99)OOI96-1 SO273-1223(99)00196-l PH:

RELATIVELY LESS POLLUTED POLLUTED A RELATIVELY DRINKING WATER WATER RESERVOIR RESERVOIR OF DRINKING METROPOLITAN ISTANBUL ISTANBUL NEAR NEAR THE METROPOLITAN BLACK SEA COAST BLACK B. B. B. Baykal, A. Tanik Tanik and and E. E. Gonenc Gonenc B. Baykal, A. ITU, Istanbul Istanbul Technical Technical University, University, Faculty Faculty o/Civil of Civil Engineering. Engineering, lTV, Department of Environmental Engineering, 80626 80626 Maslak, Maslak, Istanbul, Istanbul, Turkey Turkey Environmental Engineering, Department 0/

ABSTRACT ABSTRACT Located Sea coast coast of Lake Terkos of the the six main drinking drinking water water reservoirs of Located near near the the Black Black Sea of Turkey, Turkey, Lake Terkos is is one one of six main reservoirs of Metropolitan Istanbul, providing 25% of the water demand. With limited industrial and only only Metropolitan Istanbul, providing 25% of the water demand. With very very limited industrial activities activities and 1% its catchment area being settlements, it it is is aa relatively and comparatively less of its catchment area being devoted devoted to to settlements, relatively less less populated populated and comparatively less I% of destroyed catchment of the metropolis. In contrast to other drinking water reservoirs of Istanbul, the water destroyed catchment of the metropolis. In contrast to other drinking water reservoirs of Istanbul, the water quality of Lake Terkos is still of overall second class, implying that it can be used as a safe drinking water quality of Lake Terkos is still of overall second class, implying that it can be used as a safe drinking water resource following a conventional water treatment scheme. The most critical group of pollutants was resource following a conventional water treatment scheme. The most critical group of pollutants was determined to be nutrients, which somewhat exceed Class 2. Presently, phosphorous load is found to detennined to be nutrients, which somewhat exceed Class 2. Presently, phosphorous load is found to originate l?om point sources of domestic origin, whereas approximately half of the nitrogen load arises horn originate from point sources of domestic origin, whereas approximately half of the nitrogen load arises from forests and meadows. An appropriate management strategy, concentrating especially on the future population forests and meadows. An appropriate management strategy, concentrating especially on the future population densities, land use and an effective protection practice is needed to maintain the sustainability of the lake as a densities, land use and an effective protection practice is needed to maintain the sustainability of the lake as a drinking water resource. 0 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved drinking water resource. © 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved

KEYWORDS KEYWORDS Sea Coast; Istanbul; land use; polluting sources; population densities; water quality. Black Sea Coast; Istanbul; land use; polluting sources; population densities; water quality.

Black

INTRODUCTION INTRODUCTION Istanbul, with its population exceeding 10 million, is one of the crowded metropolises of the world and it Istanbul, with its population exceeding 10 million, is one of the crowded metropolises of the world and it a significant amount of migrating populations from all over Turkey, with further demands on receives a significant amount of migrating populations from all over Turkey, with further demands on shelter, water, employment and other needs The present water demand of about 1.1 billion cubic metres per shelter, water, employment and other needs. The present water demand of about 1.1 billion cubic metres per year is supplied from six reservoirs. Located near the Black Sea coast, Lake Terkos provides 25% of the year is supplied from six reservoirs. Located near the Black Sea coast, Lake Terkos provides 25% of the water demand. In contrast to most of the other reservoirs of Istanbul, the relatively low population and water contrast within to most the othermake reservoirs of Istanbul, the relatively low population and limited demand. industrial Inactivities its of watershed it notable among others, and the water quality therein limited industrial activities within its watershed make it notable among others, and the water quality therein is still acceptable as a drinking water resource. It should be noted however, that the recently constructed is stillEuropean acceptableMotorway as a drinking resource. be notedarea however, thatmake the recently Trans (TEM)water passing throughIt should the catchment may now it a moreconstructed attractive a more attractive Trans European Motorway (TEM) passing through the catchment area may now make district for settlements and industry, imposing a potential risk upon its sustainability for itsit intended use. district for settlements and industry, imposing a potential risk upon its sustainability for its intended use. receives

The present Turkish Water Pollution Control Regulation (TWPCR, 1988) defines protection zones around The present Control Regulation 1988) activities defines protection zones around drinking water Turkish resourcesWater and Pollution restricts residential, industrial (TWPCR, and agricultural in the catchment areas. drinking water resources and restricts residential, industrial and agricultural activities in the catchment areas. 147 147

148 148

l3. BAYKAL etal.al. B. B. B. BAYKAL et

According TWPCR, catchment are divided divided into into four zones, namely absolute, short According to to TWPCR, catchment areas areas are four zones, namely the the absolute, short range, range, medium and long long range zones, and and activities permissible in in each are defined. medium range range and range protection protection zones, activities that that are are permissible each one one are defined. Istanbul has in its its drinking drinking water Istanbul has been been experiencing experiencing aa severe severe population population increase increase in water reservoir reservoir catchment catchment areas areas in recent quality problems problems in in the in recent years, years, giving giving rise rise to to significant significant quality the water water supply. supply. Accordingly, Accordingly, water water management of the local administration. administration. Istanbul's Istanbul’s drinking drinking water management has has become become one one of of the the key key issues issues of the local water supply supply is controlled by Istanbul Water and Sewerage Authority (ISKI). Definitions similar to those is controlled by Istanbul Water and Sewerage Authority (ISKI). Definitions similar to those given given by by TWPCR are also given protection zones somewhat TWPCR are also given by by ISKl ISK] (1997), (1997), however, however, ISKI’s ISKI's definition definition regarding regarding protection zones are are somewhat less stringent. According Regulations, no industries and allowed in in the the less stringent. According to to ISKI ISKI Regulations, no settlements, settlements, industries and agriculture agriculture are are allowed absolute protection zone. However, in contrast to TWPCR, houses in a prescribed minimum amount of land absolute protection zone. However, in contrast to TWPCR, houses in a prescribed minimum amount of land may be erected starting from the short range, with increasing densities going outwards from the reservoir may be erected starting from the short range, with increasing densities going outwards from the reservoir towards the border of the catchment area. Industrial and agricultural activities are almost totally forbidden towards the border of the catchment area. Industrial and agricultural activities are almost totally forbidden till the long range protection zone. till the long range protection zone. Lake Terkos has a relatively less densely inhabited catchment area and industry is limited therein. Only 1% Lake Terkosto has a relatively less densely catchment areaatand 1% is devoted these urban functions, henceinhabited water quality is still an industry acceptableis limited level astherein. a waterOnly supply is devoted to these urban functions, hence water quality is still at an acceptable level as a water supply reservoir. However, the new Tram European Motorway, passing within the catchment area is expected to reservoir. However, new Trans Motorway, passing within the catchment area is to make the region moretheattractive for European such functions and pertinent precautions must be taken to expected control the make attractiveand for tosuch and pertinent must bewater takensupply. to control the risk of the rapidregion urbanmore development keepfunctions the sustainability of theprecautions lake as a drinking risk of rapid urban development and to keep the sustainability of the lake as a drinking water supply. This paper aims to put forth the present status of the catchment area of Lake Terkos along with some typical of the catchment area of Terkos along withincluded. some typical This paper aimsand to water put forth the present statusSome characteristics quality of the lake. recommendations forLake management are also characteristics and water quality ofthe lake. Some recommendations for management are also included. In order to save this presently less polluted lake of a highly polluted metropolis, an effective management of a highly metropolis, an effective In order to save this polluted strategy, mainly basedpresently on the less control of newlake settlements andpolluted industries, along with protectivemanagement measures, of new settlements and industries, along with with proper protective measures, strategy, mainly based the control The must be developed and on implemented. importance of providing settlements infrastructure, must be developed implemented. The importance of providing settlements with proper controlling pollution and sources and imposing good management practice for agriculture to infrastructure, maintain the controlling pollution sources andwillimposing good management practice for agriculture to maintain the sustainability of its present status be emphasized. sustainability of its present status will be emphasized. LAKE TERKOS AND ITS CATCHMENT AREA LAKETERKOS AND ITS CATCHMENT AREA Located on the European side of Istanbul, near the Black Sea coast, as seen in Figure 1, Lake Terkos is the Lake Terkos the Located on the European side among ofIstanbul, in km Figure oldest water supply reservoir those near that the are Black being Sea usedcoast, today.as Itseen is 50 from1, downtown andis has newly to the city through a reservoir area ofIt 32 km’ km andfrom a total drainage and areahas of oldest been waterconnected supply reservoir among thoseTEM. that With are being used today. is 50 downtown newly been connected to the cityofthrough Withofa metropolitan reservoir areaIstanbul. of 32 km 2 and a total drainage area of 619 km’, it provides about 25% the waterTEM. demand 619 km2 , it provides about 25% of the water demand of metropolitan Istanbul. Lake Terkos is a shallow lake which is not stratified. Its annual average water inflow is 163 million m3 with aLake reservoir capacity of 187lake million m3isand annual water withdrawal 142 million Themillion soil within the is a shallow which notanstratified. Its annual averageof water inflow m3. is 163 m3 with Terkos 3 3 drainage area is mainly impermeable and the soil structure has deteriorated due to various quarries, which an annual water withdrawal of 142 million m . The soil within the a reservoir capacity of 187 million m have led toarea significant of erosion. drainage is mainlyamounts impermeable and the soil structure has deteriorated due to various quarries, which have led to significant amounts of erosion. In terms of present land use, 77% of the catchment area is devoted to forests and meadows, whereas 17% and 1% consists agriculture andof settlements, respectively. Agricultural spread allwhereas around 17% the of presentof land use, 77% the catchment area is devoted to forestsland and ismeadows, In terms reservoir. About 10% of the forestand areasettlements, is damaged respectively. and needs afforestation. and 1% consists of agriculture Agricultural land is spread all around the reservoir. About 10% of the forest area is damaged and needs afforestation. Some characteristics of population are shown in Table 1 and the distribution of population within various protection zones is presented in Tableare2.shown Table in1 reveals increaseof population in Istanbul had beenvarious three of population Table 1that andpopulation the distribution within Some characteristics times that of the country. Interestingly, population increase within the drinking water catchment areas of the protection zones is presented in Table 2. Table 1 reveals that population increase in Istanbul had been three city had been about three and a half times of the average increase in Istanbul between 1985-1990, and times that of the country. Interestingly, population increase within the drinking water catchment areas of the currently the trend similar. low times rate of increase in the population in the between catchment1985-1990, area of Lake of the average increase in Istanbul and city had been aboutisthree and The a half Terkos is remarkable and the acceptable water quality in the lake is, to a great extent, a consequence currently the trend is similar. The low rate of increase in the population in the catchment area of of this. Lake Terkos is remarkable and the acceptable water quality in the lake is, to a great extent, a consequence of this.

149

Drinking Drinking water water reservoir reservoir ofofmetropolitan metropolitan Istanbul Istanbul

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Figure 1. Lake Terkos.

Figure I. Lake Terkos.

As can be observed from Table 2, there are two settlements in the absolute protection zone as a contradiction As can be observed from Table 2, there are two settlements in the absolute protection zone as a contradiction to the regulation, and 16 % of the population of the catchment area lives there. The amount of settlements in to the regulation, and 16 % of the population of the catchment area lives there. The amount of settlements in the short and medium range protection zones are negligible, and 73% live in the long range protection zone. the short and medium range protection zones are negligible, and 73% live in the long range protection zone. With a population distribution as such, and an increase rate of 2%, the catchment area of Lake Terkos is one With a population distribution as such, and an increase rate of2%, the catchment area of Lake Terkos is one of the relatively less populated catchment areas of Istanbul. of the relatively less populated catchment areas ofIstanbul.

0.0.B. BAYKAL BAYKAL et at. al. B. et

150

150

Table 1.1. Population Population characteristics characteristics Table Population increase increase rates rates between between 1985-1990 1985-l 990 Population Turkey 2% Turkey 2% Istanbul 6% Istanbul 6% Drinking water reservoir Drinking water reservoir catchment areas areas of of Istanbul Istanbul 20% 20% catchment Catchment area of Catchment area of 2% Lake Terkos Terkos Lake 2% Population in the Catchment area of Lake Terkos Population in the Catchment area of Lake Terkos 1970 1975 1980 1965 1965 1970 1975 1980 15 428

15428

16 020

16 937

18 590

18590

16937

16020

1985

1990 1990

1985

21 895

19 852

21895

19852

2020 2020 (projected) (projected) 68 400 68400

Table 2. Settlements in the protection zones of the catchment area of Lake Terkos (Gonenc et al., 1995) Table 2. Settlements in the protection zones of the catchment area of Lake Terkos (Gonenc et al., 1995) Protection

Protection Zone Zone

Absolute

Area Area% km2 2

km

25

%

25 51 51 62 62 449 449

TOTAL

587 100 587

settlements

4

Absolute Short Short Medium Medium Long Long TOTAL

Numberof Population Population Number of settlements 1990 % 2

49 9 11 11 16 76

22 23 3 14 14

21 21

100

%

1990

3 599

3599 1443 1443 927 927 15926 15926

21 895

21895

16

167 7 4 4 73 73

100

100

SOURCESOF POLLUTION SOURCES OF POLLUTION

In additionto the settlements discussed previously,therearesomeindustriesaspoint sources,togetherwith In additionsources to the settlements discussed previously, thereforests are some as point sources, together nonpoint consistingof agricultural activities, andindustries meadows and urban run-off withinwith the of agricultural activities, forests meadows andsources urban are run-off within the nonpoint catchment sources consisting reservoir area.Distribution of pollution loads fromand these polluting summarized in reservoir catchmentloads area.from Distribution of pollution loads from these polluting sources summarized in Table 3. Pollutant point sources were calculated using typical unit loads forare domestic sources, Table 3. Pollutant loads from point sources calculated using typical foror domestic sources, and industrial loads were determined eitherwere according to the results of unit site loads surveys from literature. and industrial loads were eithertypical according to theselected resultsfor ofthe sitereservoir surveysconsidering or from literature. Nonpoint source loads weredetermined calculatedfrom unit loads climatic Nonpoint source conditions loads wereofcalculated from typical unit for the reservoir considering climatic andtopographic the region, asdescribed byloads Tanikselected et al. (1998). and topographic conditions of the region, as described by Tanik et al. (1998).

Table3. Distributionof pollutionloads Polluting BOD5 source kg/day Polluting BODs % POINT kg/day source % Residential 1950 98 POINT 41 2 Industrial 1950 Residential 98 NONPOINT 41 2 Industrial Agricultural NONPOINT Forests & meadows Agricultural Urban Forestsrun-off & meadows TOTAL 1991 100 Urban run-off TOTAL

1991 100

Table 3. Distribution of pollution loads

Total N kg/day TotalN %

Total P kg/day Total P %

kg/day

%

kg/day

%

312 15 312

30 1 30

117 9 117

81 6 81

15

I

Toxic organicload kg/day Toxic organic%load kg/day

-

%

_ -

9

6

243 23 471 45 23 243 5 1 471 45 1046 5 100 I

7 10 7 1 10 144 I

5 7 5 17 100 I

10

100

10

100

10

100

1046

144

100

10

100

100

Thereare27 industrialplantsout of which 16 aretakenassignificantpollutionsources.Of those,eightdeal with 70%16 of are thetaken organic andalmost all ofsources. nitrogen phosphorous industrialApproximately plants out of which as load significant pollution Ofand those, eight deal Thereanimal are 27breeding. loads coming from industrial activities animal breeding activities. significant of attributed the organictoload and almost all of nitrogen Other and phosphorous with animal breeding. Approximately 70%are industrial activitiesincludenon-metallicminingandprocessing andquarries. loads coming from industrial activities are attributed to animal breeding activities. Other significant industrial activities include non-metallic mining and processing and quarries.

Drinking reservoir of Istanbul Drinking water water reservoir of metropolitan metropolitan Istanbul

1.51 151

of Table reveals that that practically practically all AA survey survey of Table 3 reveals all of of the BOD BOD load load comes comes from from domestic domestic sources. In addition, addition, a definite majority of of the the phosphorus phosphorus may attributed to domestic domestic use. In In contrast all other other drinking drinking definite majority may also be be attributed contrast to all water catchment areas of of Istanbul, Istanbul, the highest percentage percentage of the nitrogen nitrogen load load comes from forests the highest of the comes from water reservoir reservoir catchment and meadows, by domestic domestic and agricultural sources. The toxic toxic organic organic load load within within the area and meadows, followed followed by and agricultural sources. The originates agricultural activities activities due to the use of of pesticides. pesticides. Among Among the pesticides pesticides used, originates almost almost totally totally from from agricultural none listed under under Class Class 1, both by by WHO and Turkish regulations for toxic materials. materials. none are are listed I, which which is forbidden forbidden both WHO and Turkish regulations for toxic Only 7% 7% of that being being used denoted to toxic. The The Only of that used is listed listed under under Class Class 2 which which are denoted to be significantly significantly toxic. contribution of of urban run-off seems to compared to others. others. As such, the majority majority of of contribution urban run-off to be be insignificant insignificant as compared As such, polluting terms of determined to come from point point sources whereas whereas the polluting loads loads in in terms of BOD BOD and and phosphorus phosphorus is determined come from majority and toxics comes from from nonpoint nonpoint sources. sources. of nitrogen nitrogen and toxics comes majority of

WATER WATER QUALITY QUALITY Seven feed Lake Terkos. In general, these Classes I1 and to TWI'CR, TWI‘CR, Seven creeks creeks feed Lake Terkos. In general, these creeks creeks are are of of Classes and 22 according according to implying that arc acceptable from the of view view of of drinking drinking water based implying that they they are acceptable from the point point of water supply supply quality. quality. However, However, based on individual parameters some been found to exceed The parameters seem to to be be more more on individual parameters some have have been found to exceed Class Class 2. 2. The parameters which which seem critical within this framework are forms of nitrogen and some heavy metals. critical within this framework are forms of nitrogen and some heavy metals. Water in the the lake itself was in accordance accordance with MPCR and and also also in accordance with with aa Water quality quality in lake itself was evaluated evaluated both both in with MPCR in accordance more comprehensive method of classification, given by the Technical Standards of German origin (Gonenc more comprehensive method of classification, given by the Technical Standards of German origin (Gonenc et 1995; Beier Beler Baykal Baykal et latter (Ryding (Ryding and and Rast, 1989) was was used more intensively intensively for for et al., al.. 1995; et al., al., 1996). 1996). The The latter Rast, 1989) used more further decisions regarding regarding management. management. In In making making the this approach approach takes takes the classification, classification, this further evaluations evaluations and and decisions into account not only the the water water quality in the the lake also the the characteristics characteristics of of the the catchment catchment area, area, into account not only quality in lake but but also including is accomplished accomplished under under three three categories categories including pollutant pollutant loads loads introduced introduced from from this this region. region. Classification Classification is of various subcategories, subcategories, namely: namely: of criteria, criteria, consisting consisting of of various l

• • l • l

Hydrographic and territorial reflecting the the characteristics the catchment catchment area; area; Hydrographic and territorial criteria, criteria, reflecting characteristics of ofthe Trophic criteria; Trophic criteria; Salinity, special and and hygienically relevant criteria; criteria; Salinity, special hygienically relevant

and the overall quality class is determined from the average of the classes of the three categories. Technical and the overall quality class is determined from the average of the classes of the three categories. Technical standards also list the suitability of each class for various beneficial uses. Based on overall quality classes, standards also list the suitability of each class for various beneficial uses. Based on overall quality classes, Class 1 is assumed to be water that can be used for supplying drinking water upon filtration and disinfection, Class I is assumed to be water that can be used for supplying drinking water upon filtration and disinfection, Class 2 will be usable alter a typical water treatment scheme and Class 3 may only be used after complex Class 2 will be usable after a typical water treatment scheme and Class 3 may only be used after complex advanced treatment techniques. Any water body with an overall quality class exceeding that of Class 3 advanced treatment techniques. Any water body with an overall quality class exceeding that of Class 3 cannot be used for this purpose. cannot be used for this purpose. To classify a lake or a reservoir within the framework of the Technical To classify a lake or a reservoir within the framework of the Technical in the water body must be determined. In Lake Terkos, phosphorous in the water body must be determined. In Lake Terkos, phosphorous element. element.

Standards, the rate limiting Standards, the rate limiting is observed to be the rate is observed to be the rate

element element limiting limiting

Table 4 shows the results of the overall classification efforts for Lake Terkos. It can be observed that the of the classification effortsbeing for Lake Terkos.balance It can inbetrophic observed that the Table results Lake is4 ofshows overalltheClass 2, with theoverall most critical subcategory the nutrient criteria. Lake is of overall Class 2, with the most critical subcategory being the nutrient balance in trophic criteria. The significance of nutrients are also emphasized by the high value in nutrient loads from hydrographic and The significance nutrientsthe areimpact also emphasized by the area highon value in nutrient loads from hydrographic and territorial criteria, ofreflecting of the catchment the nutrient budget. territorial criteria, reflecting the impact of the catchment area on the nutrient budget.

B. B. B. B. BAYKAL BAYKAL et et al. al.

152 152

Table 4. evaluation of the water Terkos Table 4. Overall Overall evaluation ofthe water quality quality of of Lake Lake Terkos Average Class Average Class

Criteria Criteria

Rounded off Values Values Rounded off

Hydrographic Criteria Hydrographic and and Territorial Territorial Criteria 2.7 2.7 1.5 1.5 2.5 2.5

Morphometry Morphometry Catchment Area Catchment Area Nutrient Load Nutrient Load Quality class for hydrographic

and territorial criteria

Quality class for hydrographic and territorial criteria

2.2

2.2

2 2

Tropic Criteria

Tropic Criteria

1.0 1.0 4.0 4.0

Oxygen Balance Oxygen Balance Nutrient Balance Nutrient Balance Bioproductivity Bioproductivity

2.5

Quality class for trophic criteria

2.5

Quality class for trophic criteria

Salinity, Special and Hygienically

3

Relevant Criteria

Salinity, Special and Hygienically Relevant Criteria

Salinity SalinityCriteria Special SpecialRelated CriteriaCriteria Health Health Related Criteria

1.0 1.0 2.5 2.5 2.2 2.2

Quality for salinity, special and Quality for salinity, hygienically relevant special criteria and

1.9

hygienically relevant criteria

1.9

OVERALL

2.2 2.2

QUALITY

CLASS

OVERALL QUALITY CLASS

RECOMMENDATIONS

2 2 2 2

FOR MANAGEMENT

RECOMMENDATIONS FOR MANAGEMENT

Istanbul has experienced several cases of pollution, which with pertinent precautions and serious control pollution, with A pertinent precautions and serious control Istanbul has been experienced could have preventedseveral beforecases theyofhad actually which occurred. well planned and properly controlled could been prevented theycatchment had actually well planned and properly regionalhave management strategybefore for the area, occurred. within theA context of a holistic system controlled approach, covering management as much of thestrategy significant elements as possible, will bethea key issueofin a accomplishing Within regional for the catchment area, within context holistic systemthis. approach, this framework, pollution elements at the source before will it is be generated, seems to be the best management of the significant as possible, a key issue in accomplishing this. Within covering as muchcontrolling strategy. this framework, controlling pollution at the source before it is gem~rated, seems to be the best management strategy.

Presently, the water quality of Lake Terkos is at an acceptable level for supplying water to Istanbul. This may, to a large extent, be attributed relatively population level and limited industrialwater activities within This its of Lake to Terkos is at low an acceptable for supplying to Istanbul. Presently, the water quality catchment area, extent, which isbeinattributed turn a consequence of low no major motorways connecting the region to downtown to relatively population and limited industrial activities within its may, to a large Istanbul uparea, until which very recent years. However, theofnew Trans motorways European Motorway expected to downtown make this no major connectingisthe region to catchment is in turn a consequence area attractive for very industry andyears. settlements. Thisthewill probably leadMotorway to new industries moving into this the Istanbul up until recent However, newmost Trans European is expected to make catchment area,forfollowed demand forThis newwill settlements and residential Both moving industries area attractive industry by and asettlements. most probably lead to newareas. industries into and the residential be controlled with for utmost to maintain sustainability Lakeindustries Terkos as by a demand new care settlements and the residential areas. ofBoth anda catchment areas area, must followed drinking water supply. should with not be issuedcare to any industries the which are likely toofproduce wastes as thata Lake Terkos residential areas must Permits be controlled utmost to maintain sustainability are incompatible with the intended beneficial use. Definitely, no industries of any kind should be permitted drinking water supply. Permits should not be issued to any industries which are likely to produce wastes that in absolute, short protection zones. As advised throughofthe houses anyISKI kindregulation, should be no permitted arethe incompatible withand themedium intendedrange beneficial use. Definitely, no industries should be constructed in the absolute protection zone, and the population densities designated therein must in the absolute, short and medium range protection zones. As advised through the ISKI regulation, no houses be implemented without any compromises. It should be secured that all facilities required for infrastructure should be constructed in the absolute protection zone, and the population densities designated therein must must be completed before any new activities start to function. A systematic monitoring and control program be implemented without any compromises. It should be secured that all facilities required for infrastructure must be prepared and seriously implemented. The local administrations should take the responsibility to must be completed before any new activities start to function. A systematic monitoring and control program keep the water quality at least at the present level, i.e. Class 2. Efficient and timely control of new housing must be prepared and seriously implemented. The local administrations should take the responsibility to keep the water quality at least at the present level, i.e. Class 2. Efficient and timely control of ncw housing

Drinking reservoir of of metropolitan Drinking water water reservoir metropolitan Istanbul Istanbul

153 153

areas be exercised exercised in in such any illegal illegal housing, housing, squatter squatter areas, areas, and illegal areas should should be such aa way way as as to to prevent prevent any and illegal connections to the infrastructure. is also also important areas from from the connections to the infrastructure. This This is important in in terms terms of of protecting protecting the the forest forest areas the invasion constructing houses cost of of ruining forests. Moreover damaged forest forest invasion of of new-comers new-comers constructing houses at at the the cost ruining forests. Moreover the the damaged areas should be areas should be afforested. afforested. In terms terms of of nonpoint sources, in forests, agricultural activities must must be care. In nonpoint sources, in addition addition to to forests, agricultural activities be handled handled with with care. Nonpoint source control is aa difficult task since since pollutants pollutants from widespread, Nonpoint source control is difficult task from those those sources sources are are usually usually widespread, intermittent and not defined. The further complicated complicated when when sufficient are is further sufficient data, data, time time and and funding funding are intermittent and not well well defined. The task task is not available to implement good agricultural practice. While strategies can vary widely depending on not available to implement good agricultural practice. While strategies can vary widely depending on hydrologic, sociologic and agronomic factors, a key component is the identification of nonpoint sources. hydrologic, sociologic and agronomic factors, a key component is the identification of nonpoint sources. These sources are frequently of agricultural origin and the success or the failure depends largely on the These sources are frequently of agricultural origin and the success or the failure depends largely on the participation of landowners and farmers. Within this context, pertinent information and education programs participation of landowners and farmers. Within this context, pertinent information and education programs along with technical assistance is needed. Through this route, best management practice concepts may be along with technical assistance is needed. Through this route, best management practice concepts may be implemented for control at the source. implemented for control at the source. As a general principle, a regional authority responsible for the management of water resources as such is As a general principle, a regional authority responsible for the management of water resources as such is recommended. This authority should include all pertinent institutions and sectors, including local recommended. and Thistheirauthority include allmunicipalities, pertinent institutions and environmental sectors, including local governments, relevant should administrations, planning and protection governments, and their relevant administrations, municipalities, planning and environmental protection agencies, representatives from local inhabitants, industries, agriculture, etc. within the catchment area, along agencies, representatives from local inhabitants,working industries, etc. within the catchment rather area, along with universities and scientific organizations, in agriculture, harmony under good co-ordination, than with universities organizations, working in harmony under good co-ordination, rather than attempting solutionsandonscientific an individual basis. attempting solutions on an individual basis. CONCLUSIONS CONCLUSIONS Lake Terkos, near the Black Sea coast of Turkey on the European side, is one of the six main reservoirs Lake Terkos, near the Seacity. coast of Turkey European is one of theIstanbul six maincomes reservoirs supplying drinking waterBlack to the About 25% ofon thethe water demandside, of metropolitan from supplying city. About 25% and of the demand increase of metropolitan Istanbul comes from this source.drinking Due to water limitedto the industrial activities lowwater population in its catchment area, Lake this source. to limited industrial activities and low population increase in its catchment area, water Lake Terkos has anDue overall water quality class of 2, which indicates that it is still acceptable as a drinking Terkos reservoir. has an overall water quality of 2,thewhich it is still acceptable a drinking water supply However, it now class is under risk indicates of heavy that urbanization due to the asnewly constructed under the to risktheofdowntown heavy urbanization newly constructed supply reservoir. However, it now isrural motorway connecting this primarily setting area, aboutdue 50 to kmthe away. Incoming new motorway connectingand thisindustries primarilyshould rural setting the downtown area,both aboutin 50 km away. resident populations be keptto under keen control, terms of site Incoming selection, new and site selection, and resident populations industries should be kept keen control, both in terms pertinent infrastructure,and and systematic control of under performance and compliance. An of appropriate regional pertinent infrastructure, control of performance compliance. An appropriate regional management plan must and be systematic prepared and implemented withoutandcompromises in order to secure the management of plan be for prepared andbeneficial implemented sustainability the must reservoir its present use. without compromises in order to secure the sustainability of the reservoir for its present beneficial use. REFERENCES REFERENCES Beler Baykal, B., Gonenc, I. E., Merit, M., Tanik, A. and Tunay, 0. (1996). An alternative approach for evaluation of lake water quality: Sapanca Casestudy from Turkey. SC;. 34 An (12),alternative 73-81. Beier Baykal, B.,Lake Gonenc, I. E.,- Meric, M., Tanik, A. and Waf. Tunay, O.Tech., (1996). approach for evaluation of lake water Gonenc ef al (1995). protection present andWat. potential drinking water resources of Istanbul, Terkos catchment area, quality: Lake Project Sapancaon- Case study of from Turkey. Sci. Tech., 34 (12),73-81. Final report, Turkish of Environment, Environmental Protection (in Turkish). Gonenc et at. (1995). Project Ministry on protection of present and potential drinking waterAdministration resources ofIstanbul, Terkos catchment area, ISKI (1997). Water and Sewerage Administration,Environmental Regulations Protection for the protection of drinking water catchment areas (in FinalIstanbul report, Turkish Ministry of Environment, Administration (in Turkish). Turkish). ISKI (1997). 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