RAIL

Disciplines: Hydrology & Hydraulics, Survey, Floodplain Permitting

This project was located in Eastern Wisconsin and initially considered a standard replacement project. Following the site survey, the project was upgraded to emergency status due to separation of the concrete pipe culvert joints and subsequent embankment failure.

Requirements: Initially, a standard hydrologic and hydraulic culvert analysis was required. However, once upgraded to emergency status, the design timeline was greatly accelerated and became Coldwater Engineering’s top priority.

Strategy/Approach: During the site survey, Coldwater Engineering’s hydraulic engineers identified critical design elements and captured required hydraulic cross sections. A residence was located just upstream of the culvert system, creating the possibility of low water damage. Once the project was upgraded to emergency status, our hydraulic engineers were able to adjust project priorities and advise the client on the replacement structure as well as floodplain permitting requirements while construction crews mobilized to the site. Hydraulic calculations were performed using 1-D HEC-RAS and design plans were produced within a very small timeframe. In addition, concerns about creating a low water damage scenario to the upstream residence were avoided through proper structure sizing. Because Coldwater Engineering’s professionals are, above all else, hydraulic engineers, this fast-track design was easily taken from survey to submittal with little to no delays.

Disciplines: Hydrology & Hydraulics, Survey, Floodplain Permitting

Waco Bridges 889.88 and 963.07 are located in the heart of Texas. These projects posed challenging hydrologic and hydraulic design elements. Coincidental occurrence intervals, expansive floodplains, channel incisions, difficult survey conditions, scour vulnerability, limited stream gage data, and upstream storage reservoirs where among the challenges faced.

Requirements: Due to the age of the structures, a partial replacement of Bridge 889.88 and a full replacement of Bridge 963.07 were required to maintain Class I railroad standards. Coldwater Engineering was required to size recommended replacement structures that minimized constructibility concerns while satisfying regulatory requirements.

Strategy/Approach: LiDAR, public open records, Atlas 14, and available soil data were collected very early in the design. This allowed Coldwater Engineering to identify crucial design elements prior to the site survey, allowing staff to maximize efficiency while in the field. Regional familiarity and experience allowed project engineers to develop design discharges that compared well to neighboring studies. Similarly, an efficient hydraulic analysis allowed for alternative designs to be considered without modifying the budget.

Disciplines: Hydrology & Hydraulics, Survey, Environmental Permitting

La Grande Bridge 266.31 is located within the Blue Mountains of northeast Oregon. Effectively accessing this remote location and overcoming difficult field conditions were required to keep this project on budget. During Bridge 266.31’s field trip, Coldwater Engineering’s staff was able to survey other nearby projects, thereby reducing travel costs.

Requirements: In addition to the hydrology and hydraulic analysis, Coldwater Engineering was tasked with environmental permitting. Native migratory fish requirements required a comprehensive approach to the design and permitting process in order to avoid project delays. Additionally, the potential for wetlands existed, requiring a wetland delineation to be performed.

Strategy/Approach: Coldwater Engineering’s project leaders effectively collaborated, ensuring Bridge 266.31 and other nearby sites could be completed on schedule. Effective communication between engineering and scientific staff resulted in environmental concerns being addressed before finalizing the design. Replacement recommendations were presented that satisfied both the client’s design criteria and regulatory requirements.

STREAMS

Disciplines: Survey, Hydrology & Hydraulics, Bioengineering, Floodplain Permitting, Construction Inspection

The Miller Creek project intended to restore aquatic and riparian habitat. The project was located within a FEMA-designated floodplain, requiring the project to meet county floodplain regulations. Coldwater Engineering was a member of the design team and provided survey, engineering, and floodplain permitting support to the project.

Requirements: The project required a design that was permittable while also meeting environmental goals.

Strategy/Approach: A combination of floodplain lowering, floodplain treatments, and streambank treatments were utilized to improve floodplain connectivity and to improve aquatic habitat. A hydrologic and hydraulic analysis was conducted to determine proposed project impacts relative to the floodplain. Additionally, streambank calculations were performed to demonstrate project compliance with permitting regulations. Coldwater Engineering developed floodplain permitting submittals to document findings and attended a site tour to discuss the project with regulators.

ROADS & HIGHWAYS

Disciplines: Transportation Engineering, Hydrology & Hydraulics, Constructability Evaluation, Alternatives Analysis

The Mobridge Slide project is intended to implement landslide mitigation measures along a segment of highway in eastern Montana. Coldwater Engineering was a member of a larger team, serving as the project hydraulic engineer. The project required extensive collaboration between hydraulic, geotechnical, and transportation engineers.

Requirements: The proposed landslide mitigation would impact natural drainage patterns, requiring water to be diverted away from its natural course. The channel diversions resulted in a complicated hydraulic system which would ultimately contain retention, detention, culvert systems, and open channel flow. Due to scale of the project, a robust design of the hydraulic system was warranted in order to minimize risk of failure to hydraulic system; and, subsequently, the landslide mitigation.

Strategy / Approach: Stormwater modeling software was utilized to model design conditions and to account for nearly all hydrologic and hydraulic elements. This included: stormwater runoff, detention, retention, culvert capacity, and open channel conveyance. This advanced modeling approach provided for a deep understanding of site conditions and allowed for detailed design calculations. Due to the project’s complexity, multiple stakeholder meetings were held throughout the design process, allowing for open-discussion and brainstorming amongst the project team.