The refuge, also called a back water, was created using an old, silted up channel that was once part of the main river, and ensures that when local rivers suffer from rapid water level rises and flash flooding, small and young fish can be washed away or killed.
The new back water will provide a place for fish, particularly fry and yearlings, to take shelter in when needed. As the river increases in flow, fish can move into this area, and avoid being washed downstream or being exhausted by the flow.
It will also have some wider benefits for the local wildlife; providing wood in the channel for habitat creation and attracting invertebrates, such as dragonflies and damselflies as well as birds including kingfishers.
The Parks Trust landscape and operations director Rob Riekie said: "The level of successful breeding by fish populations in the River Ouzel (particularly barbel, chub, dace and roach) is low, with the quickly rising river levels and flash flooding one of the key reasons for this.
"Rather than just adding more fish to the river, we believe that creating refuges such as this one will have a long-term positive impact on the numbers of fish in the area.
"We welcomed the opportunity to partner with the Environment Agency and Wild Trout Trust on this project; it was great to bring together our collective expertise to improve conditions for the fish and other forms of wildlife along the River Ouzel."
The Parks Trust is a self-financing charity that manages and maintains over 5,000 acres of Milton Keynes’ green space.