Portfolios – Northstar Hydro, Inc.

Tidal Bridge Replacement, Deer Ilse, ME

Northstar provided hydrologic, hydraulic and scour analysis for a replacement bridge at Mill Pond in Deer Isle Stonington. The bridge is affected by tidal flow and runoff to Mill Pond. Daily tides, storm tides and upland runoff all affect water levels and flow dynamics at the bridge. Channel bed at bridge is higher than lowest tide levels creating a lag in tidal inflow and an elevation difference. Deer Isle Tidal Bridge to be Replaced Bed grade at bridge causes a tidal inflow lag and an elevation difference at low tide.

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Tidal Culvert Analysis, George Wright Road, Woolwich, ME

Northstar assisted Calderwood Engineering in their work for the Town of Woolwich to evaluate options for improvements to the culvert that conveys tidal and upland flow under George Wright Road in Woolwich. Tide levels on the downstream end of the site are subject to the complex hydraulics of the Kennebec River/Sassanoa River/Sheepscot River tidal system with islands, inlets, side channels and other features that create complex tidal/upland flow interactions in this area. Tide hydrographs from this river complex were routed through George Stevens Road and Route 1 to assess potential impacts of changing culverts in George Stevens Road. Model HECRAS 1-D…

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Skewed Bridge, Madawaska- Edmundston International Bridge, Madawaska, ME

The International Bridge over the St. John River between Madawaska, Maine and Edmundston, New Brunswick is being replaced. Northstar Hydro prepared the hydrology, hydraulics and scour analysis for this bridge replacement, facing the following issues: · Stakeholders represent international team, including MaineDOT, NBDOT, border control for United States and Canada, local residents, paper mill on both sides of the river, and other businesses and interests. · 2-Dimensional flow model employed. · River hydraulics see widely varying flood levels. · Simulation included existing bridge at 90 degree angle to flow and new skewed bridge. · Specific distribution of water levels over…

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Design Build of Six I-95 Bridge Crossings, Hampden, ME

Northstar Hydro teamed with Cianbro and WSP on this design-build project for MaineDOT. The project involved hydraulics of Souadabscook Stream which flowed under all six bridges under varying hydraulic and scour conditions. Project involved very tight timelines, a large project team and effective conveyance of complex information to the larger team with the DB framework.

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Regional Flooding Evaluation, Lye Brook, Manchester, VT

Northstar Hydro, Inc. assisted the Town of Manchester Vermont in evaluating local flooding issues associated with the area between Lye Brook and the Batten Kill. 2-Dimensional flow model of the river-wetland complex transected by several transportation corridors was developed to study flow and land use patterns. The model assisted in understanding the complex relationship between an altered stream and localized flooding. The study found that the area was an active alluvial fan 100+ years ago before the primary stream was channelized. The analysis highlighted the challenges of historic development patterns along an active stream as well as the impacts of…

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Thompson’s Bridge Replacement over Decker Cove, Southport, ME

Northstar Hydro, Inc. provided hydrologic, hydraulic and scour analysis to Maine DOT’s contractor for preliminary design for proposed replacement of the four span Thompson’s Bridge over Decker’s Cove. The project included unsteady flow modeling with model HECRAS and field monitoring to provide data on water elevations, velocities, and rate of flow through the bridge under a variety of storm and daily tide conditions. The bridge is shown in the first photo and the digital terrain model for the hydraulic model is shown in the second photo.

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Town of Brownville Junction, Maine

Culvert Replacement with Fish Passage Northstar worked with Dirigo Engineering to provide hydrologic and hydraulic engineering at the stream crossing of Front Street in Brownville Junction, Maine. The Town of Brownville proposes to replace the Front Street culvert, removing the existing undersized, perched structure with a larger hydraulically sufficient culvert that would also restore aquatic passage at the site. The existing culvert is described as two old tank cars butted end to end with the middle seam pulling apart and failing. The culvert has overtopped downstream end of the culvert is perched above an existing scour hole and is experiencing erosion…

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Highway Drainage for Proposed Interchange, Waterville, ME

Northstar Hydro worked with FST and Maine DOT to provide hydrologic and hydraulic design services for a new exit ramp from the Maine Turnpike. Northstar conducted a hydrologic analysis, drainage review, and/or sizing design of 17 cross culverts: 5 new culverts, 6 culvert extensions, and 6 additional culverts beyond the project but reviewed as part of the drainage design. The project involved an analysis of the final drainage design for a proposed new interchange on I-95 at Trafton Road in the City of Waterville and the Town of Sidney in Kennebec County, Maine. The design is a partial cloverleaf interchange with both ramp…

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Benjamin River Bridge between the Towns of Brooklin and Sedgwick, Maine.

Tidal Bridge Replacement Project Northstar Hydro worked with Kleinfelder and Maine DOT to provide hydrologic, hydraulic and scour engineering services related to replacement of the Benjamin River Bridge. Preliminary design identified key project issues including storm tide elevations, tidal cycling through the bridge, combination of tidal and upland flows and ongoing scour. The scour critical bridge was modeled using a GIS based dynamic HECRAS hydraulic model to simulate normal and storm tide conditions as well as upland flooding. Field data of tide elevation and flow velocity was also collected to provide calibration data for the hydraulic model.

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Saco River Watershed for University of New England, Biddeford, ME

Hydrologic multi-state model for researching fluvial-tidal interactions This model is designed to assist University researchers with understanding the freshwater component of the Saco River outlet area where tidal and freshwater flows meet and interact. The model was developed using ArcGIS, Geo HMS and HECHMS to create a simulation of the Saco River Basin. The model can be used to simulate design storms such as a 100-year, 24-hour rainfall event or can simulate the impacts of actual recorded NEXRAD data from real storm events. The model incorporates GIS based land use, watershed, soils, and topographic information, as well as river sections,…