He will leave the company to re-join Suez Group in a senior role, once a new chief executive has been appointed.
Bristol Water chairman Keith Ludeman said: “We are grateful for all that Luis has achieved for Bristol Water, its customers, staff and all its stakeholders in his tenure and we wish him every success as he moves back to a senior role within the Suez Group.
“Luis has led the Bristol Water team as it consistently became one of the top performing water companies for customer service.
“We will now find the right person to succeed him, build on his legacy and lead the business through the opportunities and challenges that the water industry faces over the years ahead.”
Garcia said: “I am coming close to the end of my time running Bristol Water. It has been an amazing seven years and I am proud to have been part of what we have achieved.
“What has impressed me most in my time here is the amazing passion the team has for Bristol Water and delivering for its customers. This is the key to the company’s continued success.”
Bristol Water will now begin the recruitment process for a new chief executive. In the meantime, Garcia will continue in his role.