Apart from the mammoth engineering required to make the middle route a success, over the past 10 years, dedicated individuals along the route have played their part.

Li Darong, a 38-year-old volunteer, has been cleaning the water in and around the reservoir for four years. Employed by the local forestry station, she dedicates her spare time to volunteer work.

"The environment has improved, and the water is much cleaner now," Li said with a smile as she reflected on the changes over the past decade.

"I spent my childhood along the river, grazing cattle," she said. Her family relocated in the early 2010s to make way for the reservoir. "When I protect the water here, I feel like I am also guarding my homeland underneath."

Li's responsibilities include patrolling the reservoir, collecting garbage from the water and along the shore, and promoting public awareness about water conservation.

"We remove underwater fishing cages because fishing pollutes the water and harms the environment," she explained, standing on the boat where she and her fellow volunteers work daily.

Li works alongside a team of 12 environmental volunteers, some of whom are former fishermen, whose experience and intimate knowledge of the river basin make them highly skilled at operating boats and clearing fishing cages.

Their busiest time is the flood season when tree branches and debris from upstream clog the water.

"During those times, I worked day and night, so I sent my younger daughter to stay with her grandmother," Li recalled. "When she finally saw me after a week, instead of complaining, she told me she wanted to help clean the water with me. At that moment, I felt my efforts as a volunteer were worth it."

More than 200,000 environmental volunteers like Li are registered with Danjiangkou's related volunteer organizations. Known as "Well Guardians", these volunteers play a crucial role in conserving water and ensuring the reservoir's water quality.

In August, President Xi Jinping replied to a letter from these environmental volunteers, expressing his appreciation for their efforts in protecting water resources and the environment.

The success of their efforts has resulted in the water quality of the reservoir being consistently maintained at Grade II or above over the past decade. In China's five-tier surface water quality classification system, Grade II water is suitable for drinking water sources and can also serve as sanctuaries for rare fish species.

When the water flows from the reservoir, it passes through multiple gates and undergoes rigorous quality monitoring on its way to destinations. Gates equipped with automated control systems regulate the water volume diverted to each city along the channel.

The main sluice gate that unleashes water to start its journey northward is located in Taocha village in Nanyang, Henan province.

Jin Tao, a 30-year-old who works at this massive water dispatch center, was also relocated in 2010 to make way for the project. Some 345,000 people were resettled from around the reservoir and provided with new housing.

Jin said that he and his family are content with their new life and the government's support. Under local policies, relocated villagers are provided with land and an annual stipend, and are encouraged to develop rural businesses in their new communities.

When Jin graduated from university in 2014, he joined in the construction of the project and witnessed the completion of the aqueduct section of the Tuanhe River. Following the opening of the middle route, Jin worked at dispatch centers at different levels before settling into his current role.

Today, his responsibilities include verifying dispatch data and monitoring the channel via surveillance cameras.