Known by a variety of names, the Hyatt Hidden Lakes Reserve or Hyatt Wetlands, is a 44-acre haven for birds, animals, and people located on the edge of Boise's West Bench. It will also be the site of an innovative stormwater treatment project featuring sand filters, stormwater piping, a porous pavement parking lot, restroom, an access bridge, pathways, and educational kiosks. 
A generous donation of the 22-acre wetland by local businessman Larry Hyatt and his family made it possible for Boise Parks and Recreation to purchase the remaining property in the early 1990's.
In December 2008, the Boise City Public Works Department received a $1.3 million Environmental Protection Agency (EPA) grant to create an innovative stormwater treatment demonstration project at the site.
Purpose of Project
The demonstration project will allow stormwater drainage from Ustick and Maple Grove Roads be conveyed to the wetland where it will pass through a vegetated sand filter to remove oil, grease, and other pollutants produced from roadway and roadway tributary areas. The water quality entering the wetlands after it passes through the filter is anticipated to be clean, free of sediment, oil, grease, other pollutants, and should not negatively impact the wetlands. The treated stormwater will then be discharged to the Thurman Mill Drain prior to reaching the Boise River.
Partnerships
The project also demonstrates opportunities for "win-win" partnerships between entities. The Ada County Highway District (ACHD) is a key partner and is developing additional wetlands on an adjacent 10-acre parcel they purchased, which they will donate to the City for an expanded Hyatt park once completed. They are also providing a bridge that was removed from another location. Boise and ACHD have worked together to incorporate stormwater treatment and storage into the project, and Settlers Irrigation District has also partnered to provide irrigation water during the dry season while receiving water storage benefits. Cooperative approaches, such as this, allows project dollars to stretch further and to resolve multiple problems at once.
A Reserve for All to Enjoy
As proposed, the area will remain a prime wildlife habitat and feature some trailheads, pathways, and overlook areas. Enhancements also include water control structures, creation of protected habitat islands, enlarged open water areas, and supplemental plantings to encourage diverse wildlife habitat and improve riparian areas.
The site will also feature interactive educational elements and interpretive signs to inform the public about water resource impacts and water re-use opportunities within urban developments. Once the stormwater treatment system and wetlands plants are fully established, the Boise Parks and Recreation Department will administer the site as a passive park where people can enjoy the natural amenities the reserve has to offer.