Story #14 - Trout Hatchery Project Profile
/Story #14 is a profile of a unique project at a Trout Hatchery in the State of Maryland.
SSM Baltimore Office: Fish Hatchery for State of Maryland
SSM team members designed renovations for a trout hatchery that would then produce rainbow trout for Maryland fishermen. SSM was assigned the schematic design, design development, and construction documents phases of the renovation project.
From 300,000 Eggs to 85,000 Trout
At the time of this project, the hatching process at this location went as follows: 300,000 eggs are flown from commercial hatcheries in the State of Washington to the Maryland hatcheries, where they are incubated in hatching troughs for about 20 days until they hatch, and the fingerlings remain for about three months.
The trout from both hatcheries are then transferred to outdoor fingerling ponds at the hatchery. Then, after a further period, transferred to raceways where they stay until they reach stock size of 10 to 18 inches. Rearing from egg to stock size takes “16 months and a lot of care,” according to John P. Horst, SSM Project Manager at the time.
The renovations that SSM was brought on for were to increase production at the hatchery. Two collapsed 100 ft. raceways which were not used for years were restored to production, supplementing 17 existing 200 ft. raceways. Raceways were 6 ft. wide and about 4 ft. deep. A new pumping system was also to be designed to recirculate water from the hatchery outfall to a point just downstream from the 3,000 gpm spring which feeds the system.
Increased Flow Speeds Growth of Fish
The new pumps were incorporated to increase total flow through the raceways to about 5,000 gpm, and to raise the water temperature a couple of degrees. Both factors would contribute to an increase in the growth rate of the trout, and with the added raceways, approximately double the production of the hatchery.
Other renovations included improvements to stream banks; a movable floating cover over the natural spring to block out ultraviolet light and cut down algae growth; replacement of a water supply line from the spring to the hatchery building; rebuilding fingerling pond walls’ bridge reconstruction; resurfacing of paved areas around raceways; and improvements to a shop building and a residence.
