Hydraulic Modeling Evaluates
Several Sewersheds

Project Name
Hydraulic Modeling and Capacity Evaluation
Baltimore County
Baltimore County, Maryland
Service Period

RJN was selected to assist Baltimore County with developing Sewershed Repair, Replacement, and Rehabilitation plans (SRRR) and services in compliance with its Consent Decree. RJN prepared the SRRR plans for four sewersheds in the southeast portion of the County’s service area. These plans involved reviewing available data, performing condition field inspections, and developing recommendations for rehabilitation measures to address structural deficiencies, address identified capacity issues, and eliminate inflow/infiltration from the system. Projects, assigned under on-call work orders, addressed four non-priority sewersheds as identified in the Consent Decree. In addition, under subcontract to Hazen and Sawyer, RJN performed hydraulic modeling of two of the four south area sewersheds, including surface inspection of all modeled manholes to verify pipe connectivity and manhole rim and pipe invert elevations. RJN has actively worked for the County since 2005, implementing the ongoing county-wide rain gauge program and providing flow monitoring, SRRR plan development, rehabilitation design, performance assesment, and force main inspection services. RJN currently has several open task orders under the on-call SRRR project, one of which includes performing hydraulic modeling as needed for the County.

Project Metrics

  • 700 manhole inspections for pipe connectivity and manhole rim / pipe invert elevation verification
  • Hydraulic modeling of Essex and Duck Creek sewersheds; all pipes 10” and greater in diameter, plus any smaller diameter pipes integral to the capacity evaluation


  • County-wide rain gauging
  • Flow monitoring, multiple sewersheds
  • SSES condition field inspections
  • Hydraulic modeling
  • GIS mapping
  • SRRR plan preparation
  • Force main assessment and inspection
  • Stream crossing and exposed pipe evaluation
  • Rehabilitation design
  • Post-rehabilitation flow monitoring and performance assessment