The City and County of Denver (Denver) retained Matrix Design Group, Inc. to create an update to the Denver Storm Drainage Master Plan as part of a capital improvement planning effort. This project comprehensively analyzed 155 sq mi of urban development for necessary drainage infrastructure upgrades and improvements. Major drainageways evaluated for the plan include the South Platte River, Cherry Creek, and other local drainage systems. The Denver Storm Drainage Master Plan serves as the single integrated authoritative reference for planning and programming for ongoing and future development of Denver’s stormwater drainage system. This storm master plan is updated every 5 years by ordinance.

The storm drainage master plan is extensively utilized by the City and County of Denver and its stakeholders, including city government, staff, and residents; the Denver Regional Council of Governments; Urban Drainage and Flood Control District; and the Colorado Water Conservation Board. The Matrix team guided the decision-making process, identified needs, provided alternative choices, and performed the technical evaluations to inform the selection process. Matrix’s role provided expert technical support and innovative approaches that both respected constraints and capitalized on opportunities. Additionally, Matrix conducted workshops and public meetings to encourage support for the project, established a capital improvement program that matched construction with funding sources, and provided prioritized infrastructure in a timely manner.

The Matrix team prepared detailed hydrologic models using Urban Drainage CUHP & SWMM and completed field reconnaissance work to confirm the effectiveness of existing hydraulic features. In addition, Matrix conducted interviews on individual drainage basins to obtain historic information on floods in order to ensure that system deficiencies were properly identified thus paving the way for the development of solutions compatible with the interests, values, and land uses of each neighbor. These basin-by-basin analyses enabled implementation plans and financing strategies, which progressively improve facilities and establish potential cost recovery mechanisms, to be created.

Watershed-based master planning enabled water quality and quantity objectives to be fully integrated. The master plan also worked in conjunction with the City of Denver’s municipal NPDES permit to improve water quality and establish best management practices. A treatment train approach was employed to layer onsite and regional controls to systematically achieve water quality objectives.

Project Highlights:

  • Existing and future impervious surface analysis
  • Comprehensive citywide data assessment and improvement
  • Geometric network analysis
  • GIS analysis to preprocess hydrologic models
  • GIS linked cost model
  • Customized map book application

Services included:

  • Hydrologic Modeling and Analysis
  • Watershed Planning
  • Stormwater Infrastructure Design
  • Infrastructure Assessment and  Master Planning
  • Cost Estimating