One of the main tributaries of the Büyük Menderes River is the Suçıkan Stream, situated in the Suçıkan district in Dinar, Afyon. Away from human interference, the stream still remains unpolluted and its crystal-clear waters keep flowing.

Kaklık Cave, located in the small town of Kaklık in the Honaz district of Denizli province, is decorated with dripstone stalactites and stalagmites. With its travertine terraces, it resembles Pamukkale and is therefore known locally as "Little Pamukkale". Natural pools in the cave are home to an endemic killifish species (Anatolichthys irregularis), which cannot be found elsewhere in the world. Its survival depends on this very special water source.

The Çürüksu Stream, one of the main tributaries of the river, joins the Büyük Menderes at the border between Afyon and Denizli. The Çürüksu Stream is under intense pressure from organic pollution due to urban and industrial wastewater. The water quality at this point falls considerably. Extremely hot wastewater from textile dyehouses causes sudden changes in the water temperature. The results of a water quality study we conducted across the basin indicate that the highest water temperatures among all sample points were measured in this region (29,8^°C) and that these temperatures do not allow for aquatic life in the region.
The water quality of the Çürüksu Stream where it joins the Büyük Menderes River goes down to an exceptionally low grade 4. Depending on the colors affecting the wastewater from textile dyehouses, the stream sometimes flows red and sometimes black.
The textile sector, which is the lifeblood of Denizli's economy, is of critical importance, not only for this city but also for the Turkish economy. Home textile products produced in and exported from Denizli account for 60% of Turkey's home textile exports. The textile industry uses high amounts of water in the dyeing and finishing processes. The Büyük Menderes basin is under water stress in terms of the amount of water available, which poses a risk to the availability of water in the basin and the future of the textile sector.
What do we do?
We encourage the transformation of industry through the implementation of cleaner production practices in textile enterprises.
Cleaner Production includes changes in water, energy and chemical use; contributes to an environmentally friendly transformation that uses water and energy more efficiently and opts for environmentally friendly chemicals; and aims to reduce the amount of wastewater and chemical pollutants in wastewater. This reduces the negative impact of the textile industry on water and biodiversity.
Cleaner production benefits not only nature/or Büyük Menderes, but also the textile industry. Cleaner production practices help textile companies reduce production costs. With cleaner production, it has become easier for them to meet the rapidly growing demands of consumers and brands for environment-friendly production.
In partnership with the Southern Aegean Development Agency (GEKA) and the Denizli Chamber of Industry (DSO), we have launched a cleaner production transformation process in Denizli's textile industry with the support of global brands.
We brought public institutions, textile brands and technical experts together with textile companies in Denizli and exchanged good practices. We prepared and made available the “Cleaner Production Guide for the Textile Sector”. Nineteen manufacturing companies in Denizli became “Pioneers of Change” and started to invest in cleaner production.
We called on textile brands to take action to support the transition to clean production. As a result of our call to local and global brands, the “Brands Committee for Collective Action” was established.
GEKA introduced the Cleaner Production Investment Grant program. This program gives priority to the textile industry among others and provides grant support for companies investing in cleaner production. Within the framework of the program, 6 textile enterprises received 2,176,840.73 million TL worth of grant support and invested approximately 5 million TL in cleaner production practices. As a result of these investments, 570,000 cubic meters of water and 200,000 kwh of energy have been saved.
With this collective action that we started in 2018 with public and private stakeholders, we aim to contribute to the cleaner production investments of all textile companies in the basin, thus increasing the water quality in the Büyük Menderes River.

Thirty-five of Turkey's 48 geothermal power plants are in the Büyük Menderes basin, one of the top-ranking regions in the country in terms of fertile soils and water resources. Although geothermal energy is a renewable alternative to fossil fuels, liquid and gas wastes containing chemical substances, especially boron and arsenic, are discharged directly to the soil, underground and surface waters without re-injection, threatening the ecosystems in the entire basin. Installed within or near olive and fig groves and first grade farmlands and irrigation lands, the geothermal power plants also affect the health of agricultural practices.
We demand that no new wells are drilled and no new sites are licensed without necessary legislative regulations and adequate inspections, and that existing power plants discharge their wastewater through re-injection. We strive to raise awareness about geothermal-induced pollution.

The present-day Söke Plain was formed when the Gulf of Latmos, which was a large bay in the past, was filled with alluvium carried by the Büyük Menderes over the previous 5,000 years. The Söke Plain, which is situated in Aydın province, is the largest cotton production area in the Aegean Region in terms of the size of arable land and amount of production and ranks second in Turkey by hosting 14% national cotton production. Aydın has 7,000 cotton farmers, and cotton production in the region contributes to the livelihood of more than 30,000 people. Söke has a significant share in Aydın's cotton production. Cotton production started in the 1930s, and the 1950s were marked by a major increase in cotton production, facilitated by the increase of irrigation possibilities, agricultural pest control and the use of tractors.
Cotton is grown on 98% of the agricultural land in Söke, and 2,890 cotton producers operate in the region.
The water quality research we have conducted shows that the water resources that feed the Söke Plain and are used in agricultural production are of low quality. When pollution brought by the river from the upper basin is combined with the pollution caused by agricultural chemicals in cotton production, the water quality in the Söke Plain decreases significantly.
Flood irrigation is the most widely used technique across the plain. The water use efficiency of this method is very low. Most of the water used is lost due to evaporation, using more water than needed for agricultural activities. Flood irrigation also leads to soil erosion, salinization and using more fertilizers and pesticides. Organic matter content of cotton farmlands in Söke has fallen considerably. While good quality soil for agriculture contains 3% organic matter, in Söke's farmlands this figure is 0.5%. The Söke Plain is among the regions that will be affected by drought due to climate change, and the sustainability of cotton production in the region is at risk.
What do we do?
We aim to create a long-term change that will reduce the pressure of cotton production on nature and ensure the long-term sustainability of cotton production in this region and thus ensure the livelihood of the farmers.
Since 2018, we have been the implementation partner of the Good Cotton Practices Association, which is a member of the Better Cotton Initiative, a program implemented on 5 continents and in 23 countries. Better Cotton is a standard that aims to make the future of cotton producers and the industry sustainable. With Better Cotton, we aim to ensure that inputs in cotton production such as pesticides, fertilizers and water are used effectively and kept to a minimum; to protect and improve soil health and natural habitats in agricultural lands, and to increase the welfare of farmers. We offer farmers a variety of opportunities, such as pilot field studies, free soil analysis, agricultural engineer support and so on. We carry out our work in cooperation with institutions such as Tariş cooperatives, Chambers of Agriculture, Sub-provincial Directorates of Agriculture, Aydın Provincial Directorate of Agriculture and Forestry and the South Aegean Development Agency (GEKA). Within the scope of the Better Cotton framework, 1400 farmers received the Better Cotton training in 2018-2019, and 359 of them received the Better Cotton license. In 2019-2020, 1,125 farmers received the training, and 525 farmers were licensed. In the 2020-2021 period, 359 farmers received a three-year Better Cotton license.
We facilitated the establishment of the Söke Cotton Water Stewardship Steering Committee (SPSKYK) in 2019 in partnership with public institutions, the private sector and non-governmental organizations. The Board is working to promote more efficient use of water in cotton farming in the Söke Plain, to ensure the sustainability of this activity and to reduce the impact of cotton production on water resources.
The Söke Cotton Water Stewardship Steering Committee (SPSKYK) consists of the following organizations: Agrita, a herbal production company in Söke, Aydın Metropolitan Municipality, Aydın Provincial Directorate of Agriculture and Forestry, Pressurized Irrigation Industrialists Association (BASUSAD), Good Cotton Practices Association (IPUD), Söke Plain Irrigation Association, Söke Commodity Exchange, Söke Chamber of Agriculture, Söktaş, a textile production company in Söke, Söke Cotton and Oil Seeds Agricultural Sales Cooperative no. 131 of Tariş and WWF Turkey.  
The Committee carried out a modern irrigation pilot project on an area of approximately 1,000 decares next to the border of the Büyük Menderes Delta, which qualifies as an internationally important wetland in Söke.
The project aims to achieve:

• 50% savings in water use,
• 20% reduction in input costs,
• 100 kg increase in yield per decar,
• improved soil and water quality,
• prevention of erosion, and
• reducing the impacts of cotton production on natural areas and biodiversity.

Lake Bafa is a wetland of international importance. As the alluvium carried by the Büyük Menderes structured the Söke Plain, the sea passage gradually closed, creating Lake Bafa. With 6000 hectares of surface area, the lake was declared a nature park in 1989 and is also an Important Bird Area*.
Another organism that Lake Bafa hosts is the European eel (Anguilla anguilla). The eels hatch in the Gulf of Mexico and arrive on the coasts of Europe and the Eastern Mediterranean after a long journey. After spending almost 20 years in Lake Bafa, they migrate back for breeding in the Gulf of Mexico, where their life ends. With such a challenging life cycle, the European eel is classified as Critically Endangered (CR) on a global level by the IUCN (International Union for Conservation of Nature). Considered a symbol of Lake Bafa, this species is also important for the regional economy. Maintaining healthy populations of critically endangered eels is crucial to the sustainability of fisheries in the lake.
According to our ecosystem services study, Lake Bafa supports agricultural production that takes place around it. It is of significant economic value thanks to the fish stocks living in the lake. The lake regulates the climate in the region and feeds the surface waters and groundwaters. It is also an attractive landscape with its cultural, natural and aesthetic characteristics.
However, urban and industrial wastewater from the upper basin and hydrological interventions in the lake negatively affect its water quality and threaten the organisms inside it.

*Important Bird Areas are globally important areas for the conservation of bird species. The goal of Important Bird Areas is to ensure the sustainability of birds along with other living creatures and ecosystems. These areas are selected according to scientific criteria developed by BirdLife International.
Lake Bafa is home to 261 bird species, including the globally threatened Dalmatian pelican, 22 reptile species and 19 mammal species. The lake and its surroundings also give life to 325 plant species, including several endemic orchid species.
What do we do?
We identified, through scientific methods, the steps needed to improve the health of the lake and its benefits to humans. We aim to regulate the lake's hydrology in a way that improves its health.

Let’s take a brief look at the history of the basin in the ancient city of Miletus.
Located between two wetlands of international importance, i.e. Bafa Lake and the Büyük Menderes Delta, Miletus is the hometown of Thales, one of the founders of philosophy. It was right here, where the Büyük Menderes flows, that Thales, born and bred in this land in the 6th century BC, came up with the hypothesis that the essence and building block of everything is water. According to his theory, water is the arkhe, the source of everything. A life source for living beings, a force that structures earthly systems. Everything gains their form by water.
The Büyük Menderes River was called the Meandros in antiquity. The most prominent feature of the Meandros River is the winding path it follows. Inspired by the river's name, the word "meander" became proverbial in several languages to describe the winding and curving course of rivers. The word meander derives from the ancient name of the Büyük Menderes River, the Meandros.
Famous historian Herodotus also lived here, where the Büyük Menderes River flowed in the 5th century BC. So many civilizations had lived here that Herodotus called the basin “The Valley of Civilizations”.
One of these civilizations was the Lydians, the first civilization to use money. The luminous waters of the Büyük Menderes River were embossed on their coins.
With the completion of the Aydın - İzmir railway in 1866, the products grown in the Büyük Menderes basin began to be delivered to İzmir, the closest trade port. The Büyük Menderes Basin was opened up to the world with its tobacco and cotton, figs, grapes, olives, licorice roots, wool, mohair, and woven fabrics.
One of the first places where the steps of industrialization based on agricultural production were taken in the 1930s was the Büyük Menderes Basin. Nazilli was selected as the location to build a printed cotton fabric factory, based on its availing climatic and territorial conditions for cotton farming. These years also witnessed the development of traditional leather processing in Uşak and weaving in Denizli. From before the common era to the present day, the Büyük Menderes River has continued to provide water to millions of people, provide a habitat to countless living things and be the lifeblood of the economy.

The Büyük Menderes Delta, stretching over where the Büyük Menderes River meets the sea, is another wetland of international importance. The delta offers great richness in terms of biodiversity. It is commonly visited by globally threatened species, such as Mediterranean monk seals, Eurasian otters and loggerhead turtles (Caretta caretta). Also an Important Bird Area, the delta is one of the most important breeding grounds in the Western Palearctic region for the globally endangered Dalmatian pelican.
In the 1950s and 60s, the Dalmatian pelican would breed in 17 different wetlands in Turkey; however, due to the effect of human activities, it now uses only five areas for breeding: Gediz, the Büyük Menderes Delta, Manyas, Aktaş and Işıklı Lake. The species is protected under international conventions.
The Büyük Menderes Delta is one of the few areas where the Mediterranean gull (Larus melanocephalus) breeds in Turkey. Other important species that can be found in the basin is the lesser kestrel (Falco naumanni) and the greater flamingo (Phoenicopterus roseus) which can be observed in large flocks in the summer and winter respectively. The delta is widely covered with salt marshes, providing a nesting ground for various bird species. With their carbon sequestration capacities, the salt marshes make ecosystems resilient to climate change.
Situated on the natural border between the delta and the Dilek Peninsula is the Karina Lagoon with its unique view. The facilities on the shore of this lagoon and traditional lagoon fisheries are important sources of livelihood for the local people.
According to our ecosystem services study, lagoons in the delta play a significant role for commercial and recreational fisheries. The delta provides the abundant amount of water necessary for agricultural activities, especially cotton farming. However, as some farmlands are acquired by transforming wetland ecosystems, the benefits that these areas can naturally provide, such as carbon sequestration, are on the decrease. Dilek Peninsula and the Büyük Menderes Delta National Park welcome 45,000-50,000 visitors a year thanks to their natural beauty and the cultural heritage they offer.
What do we do?
We aim to improve/preserve the ecosystems of the Büyük Menderes Delta and to implement practices that will ensure the sustainability of living creatures that depend on these ecosystems while supplying water for agricultural activities in and around the delta.
The Büyük Menderes River, which springs from Suçıkan in Afyon, completes its journey in the Büyük Menderes Delta, where it reaches the sea. It is possible for the Büyük Menderes River to continue its journey and to give life to the basin with the joint efforts of the public, the private sector, civil society and academia and the support of individuals. #TogetherPossible