This report was prepared in accordance with the agreement signed between Denizli Municipality and Egebiyoteknoloji Inc. within the scope of “Denizli Municipality; Municipality Services Project: Environmental Assessment Consultancy Services for Water Supply System Rehabilitation and Sewer System Projects”. In the report, background information on water supply system rehabilitation and sewer system projects (including stormwater), description of the project area, impact mitigation and monitoring plans, assessments on the institutional structure of Denizli Municipality that is responsible from the execution of the project and the minutes of the public awareness meeting are presented in separate sections.
Denizli is situated in Aegean Region of Turkey and covers an area of approximately 11,868 km2. The city stands out with tourism and industry. Based on the 2000 census results, the population of the province is 275,480 as reported by Turkish Statistical Institute (TUIK). Being a rapidly growing city, Denizli experiences problems with regards to its infrastructural systems about which, several investment activities have been initiated where Denizli Municipality is being considered to be the major beneficiary. The first one of these issues is the general deficiency of the water supply system and the associated water losses. According to the “Final Feasibility Report” prepared in June 2005 by KAYA (KAYA Consulting and Engineering Inc.) - SNS (SNS Consulting and Engineering Inc.) Joint Venture, the total amount of water supplied to the system in 2003 was 23,849,688 m3/year of which, only 14,815,114 m3/year (app. 62%) was legally consumed and the remaining 9,034,574 m3/year (app. 38%) was reported as “water losses”. It was further reported that 438,320 m3/year (app. 2%) of these losses were due to illegal consumption, incorrect measurement and defective water meters, which are typically difficult to prevent. However, the remaining 8,596,254 m3/year of these losses (app. 36% of total water supplied to the city) are physical losses that could be minimized by the rehabilitation of the infrastructure. On the other hand, it was pointed out in the “Technical Assessment Report of the Denizli Water Supply System Feasibility Works” dated February 2005 that a major portion of the water supply system would need to be renewed as well as the capacity and the service area of the existing infrastructure would need to be increased since the current water supply network was old and inadequate, could no longer satisfy the demand both qualitatively and quantitatively, and the system experienced frequent failures resulting in a decline in water and service quality further resulting in difficulties in providing a satisfactory service to the existing and future customers. Originating from these necessities, the Denizli Water Supply Rehabilitation project has been initiated.
On the other hand, the city of Denizli also experiences problems with regards to its insufficient sewer and stormwater system. The attempts on the construction of a sewer system in Denizli (Center) have been initiated in 1980’s, and several tasks were completed till now. Among these tasks, which were mainly executed under the control of the Bank of Provinces, the construction of 105,279 m network and 2,400 m main collector has been completed as of 1990. In addition, another project [Denizli – Center, Bagirsak (Gokpinar) Creek watershed sewerage system implementation project] has been prepared in 2001 to collect the wastewaters originating from the protection area of the Gokpinar Reservoir that was allocated for drinking water supply to Denizli. Furthermore, another sewer system project (Bagirsak Creek and Bozburun Region sewer system project) was prepared to provide the sewer system requirements of the new municipalities and villages, which joined Denizli Municipality jurisdiction in accordance with the Resolution on the “Determination of the Border” published in the Official Gazette dated 12 August 2006. Within the scope of this project tendered in February 2006, suitable areas (with regards to elevation and location) are connected to the existing sewer network. In the meanwhile, Denizli Municipality has modified the Bagirsak Creek collector project and connected 70% of this line to 1600 mm diameter Ellez Collector in order to protect the environment from further damage. Thus, wastewaters that were previously discharged to the receiving environment without any treatment have been redirected to the existing Eskihisar Wastewater Treatment Plant. This modification was an important decision of the municipality for environmental protection. Despite these efforts, the majority of the sewer lines that currently serve to collect the wastewaters of Denizli city center are old and don’t operate properly. In addition the existing lines serve as combined system, because there are many illegal connections to the sewer line from the roofs and thus during the storm, the capacity is exceeded. Therefore the system needs to be rehabilitated and separated.
Finally, stormwater is another problem that affects the quality of life and the traffic in the city center. Although a stormwater collection network exists in the city center, this system is old and under-capacity. In addition, as noted above, most of the sewerage system is also used for storm water. Thus, a new stormwater drainage system is required particularly for the city center to drain the storm separately.
Consequently, Denizli Municipality, as the major beneficiary, has initiated a number of infrastructure projects related to the rehabilitation of the water supply system and the completion of the deficiencies of the wastewater collection and stormwater drainage system. Tendering and implementation of these projects are important requirements to be fulfilled in the shortest time frame possible.