Capitol Region Watershed District (CRWD) owns, operates and maintains the Trout Brook Storm Sewer System, a “trunk conveyor” or interceptor storm sewer that receives runoff from the Cities of Saint Paul, Roseville, Falcon Heights and Maplewood as well as Ramsey County and Minnesota Department of Transportation. The system was constructed between the 1880’s and 1950’s and served as a combined sanitary and storm sewer system. TBI ranges from 5 to 11 feet in diameter and tunnel shapes include circular, rectangular and horseshoe. In 1988, the systems were separated. Today, TBI carries rainwater and snowmelt from city streets, parking lots and other hard surfaces to the Mississippi River. Click here to learn more about TBI.
CRWD completes regular inspections, minor maintenance and capital repairs of TBI to ensure the system functions properly and effectively. Detailed summaries of past and present major repair work are included below.
2007-2009: As part of the transfer of TBI from Met Council to CRWD, the District repaired two sections of pipe that were in poor condition. First, CRWD replaced 200 feet of 8-foot diameter pipe near Willow Reserve. Second, CRWD rehabilitated a 3,800-foot section of TBI located in the vicinity of Maryland Avenue, L’Orient Street, and I-35E. This section was in poor condition due to severe cracking and settlement beneath the streets. A 200-foot settled or “sag” area of the 10-foot diameter storm sewer pipe beneath L’Orient Street required a full replacement. Click here to view a map of the exact locations of the repairs.
2012-2013: During the design phase of the Interstate 35E/Cayuga Reconstruction Project from University Avenue to Maryland Avenue in Saint Paul, the Minnesota Department of Transportation determined that a portion of TBI would have to be moved to avoid conflicts with I-35E bridge piers proposed for an area near Mississippi and Cayuga Streets. Constructed in two phases, the new Trout Brook alignment involved abandoning a 630-foot section of existing pipe and replacing it with 830-feet of new pipe in a nearby location.
The first phase of the project included building a new 160-foot TBI railroad crossing within a 30-hour work window and required shutdown of mainline railroad tracks. Afterwards, an additional 400-foot section of new storm sewer pipes was installed. During the second phase of the project, 270-feet of new pipe and the transition sections between the old and new pipe sections were constructed. Once the new TBI alignment was “on-line,” the old TBI alignment was abandoned by filling it in or removing it entirely.
2016-2017: CRWD is repairing a half mile stretch of the oldest section of TBI that starts just south of Phalen Boulevard and ends north of I-94 in Saint Paul. Most of this repair section is a 10’ x 10’ horseshoe arch comprised of limestone blocks in the arch portion and brick pavers on the bottom. Repairs include replacing damaged or missing mortar between joints of the limestone blocks, installing a concrete liner in a 500-foot section with higher amount of defects, and removing calcium deposits in the pipe. Unlike previous TBI repair projects conducted by CRWD, this 100-year old section of TBI was in better condition and did not warrant full replacement of any pipe sections.
Click on the video below to see the first phase of the 2012 repair project.