On-Call Water Resources Engineering
Montgomery County, MD
AMT was selected for the annual services contract to perform water resource engineering services to meet MS4 permit requirements. AMT provided a combination of planning, design, permitting, bidding phase and construction phase services for 17 existing pond facilities, 30 ESD/LID facilities located at Germantown MARC station, Longwood Community Center and the Potomac Community Center. and more than 3 miles of stream restoration from 3 separate task orders. AMT partnered with a team of subconsultants to include geotechnical engineers and landscape architects to achieve minority business participation requirements.
General Engineering Services: General engineering services provided by AMT includes the preparation of studies, site investigation and evaluations, reports and exhibits; wetlands/waterways delineations; concept designs; construction documents, including any/all drawings, calculations, reports, details, specifications, and project manuals necessary for contract and bidding purposes; preparation for construction cost estimates; and the review of studies, evaluations, reports and construction documents for completeness.
Stormwater Management Pond Retrofits: For 17 existing pond facilities, AMT provided preliminary assessment and field review of the facilities, concept planning, H&H modeling using TR-20, TR-55, HydroCAD, record document review, field surveying and field work for NRI/FSD preparation, three (3) alternatives are prepared to identify available scenarios to provide water quality treatment and channel protection volume to the maximum extent practical. Based on the preferred alternate, AMT prepared permitting plans for SWM, erosion control, MDE Joint Permit Application, M-NPCC Forest Conservation, Dam Breach Hazard Classification, Maintenance of Traffic Plans, work within the public right of way and work within the WSSC right of way. AMT also updated the County’s GIS database based.
Low Impact Design Retrofits: AMT provided preliminary assessment and field review of the facilities, concept planning, H&H modeling using TR-20, TR-55, HydroCAD, record document review, field surveying and field work for NRI/FSD preparation, preparation of construction and permitting documents for low impact design treatment facilities such as bioretention facilities, rain gardens and sand filters. AMT obtained permit approvals for SWM, erosion control, MDE Joint Permit, Forest Conservation, and work in the public R/W.
Stream Restoration Projects: AMT designed stream restoration for 8,000 LF of Gunners Branch and tributaries, 1,600 LF on the Old Farm tributary to Cabin John Creek and 8,000 LF of Rock Creek tributaries in the Grosvenor area. AMT provided a stream mechanics and fluvial geomorphological stream assessment utilizing Rosgen III methodology. AMT prepared extensive hydrologic modeling, calibrated with geomorphic model, and observed flooding conditions. HEC-RAS modeling was performed to evaluate the existing and proposed geometry, stabilization methods, in-stream structures and sediment transport as well as floodplain management and FEMA coordination. Designs include geometric improvements, maintaining fish passage and providing opportunities for enhancing in-stream habitat using Natural Channel Design (NCD) methodologies and a combination of hard armoring and bioengineering techniques. AMT prepared and obtained permits from MCDPS, M-NCPPC and FEMA