State Mega Project of Kanal İstanbul: Study, Design, and Consultancy: The Kanal İstanbul Project, commissioned by the Ministry of Transport, Maritime Affairs, and Communications and carried out under the Directorate General of Infrastructure Investments, is a planned waterway connecting the Black Sea to the Marmara Sea. The 45-kilometer-long channel will stretch from Küçükçekmece Lake and Sazlıdere Dam in the south to the Durusu region in the north. With a depth of 20.75 meters and a narrowest width of 275 meters, the project aims to alleviate the increasing maritime traffic burden on the Istanbul Strait. Currently accommodating an annual average of 50,000 ships, the Istanbul Strait is expected to face increased traffic due to growing global economic activities. This surge, coupled with larger ship sizes and transporting hazardous materials such as oil, poses significant risks, underscoring the need for an alternative passage. Hydrodynamic and Water Quality Analyses: Seasonal measurements of current, wave, water level, temperature, salinity, and turbidity were conducted. The resulting data were integrated into hydrodynamic and water quality models to evaluate the project's environmental impacts. Sediment Transport Modeling: Numerical sediment transport modeling determined that the project would not cause adverse sediment movement along the Black Sea or Marmara coasts or within the canal. The findings also confirmed no significant impact on Terkos Lake. Results from sediment and wave modeling were incorporated into the design of breakwaters. Hydrodynamic Numerical Modeling: The Bosphorus System (Çanakkale Strait - Marmara Sea - Istanbul Strait) was modeled hydrodynamically using field measurements and existing data. Kanal İstanbul was then added to this model to evaluate its effects on current speeds and water level changes, which were further used in Environmental Impact Assessment (EIA) studies. Wave and Wind Climate Modeling: Detailed models were developed to analyze the wave and wind climate along the canal route, providing data critical for maritime operations and structural designs. Meteorological and Hydrological Studies: Peak flood discharges and hydrographs for surface streams along the canal route were calculated using long-term meteorological data, including precipitation, temperature, evaporation, relative humidity, wind, and snow. Water Quality Numerical Modeling: A highly sensitive numerical model was developed to assess the impact of Kanal İstanbul on water quality. This model quantified changes in water exchange between the Black Sea and Marmara Sea and evaluated their environmental implications. The modeling and analyses for the Kanal İstanbul Project provided critical insights into Environmental Impact:   Changes in water quality and hydrodynamics due to the project were evaluated for compliance with environmental regulations. Infrastructure Design: Results from wave, sediment, and hydrodynamic models informed the design of breakwaters and navigation channels. The Kanal İstanbul Project represents a significant initiative to manage maritime traffic efficiently while minimizing environmental impacts, ensuring safe navigation, and supporting sustainable regional development.