Storm Drainage Criteria

Storm Drainage Design Criteria

The purpose of the Storm Drainage Design Criteria Manual is to set forth the technical criteria to be used in the analysis and design of drainage systems within the Town.

• Storm Drainage Design Criteria REVISED 7-1-20 (PDF)

Master Drainage Plan

The town is presently experiencing rapid growth and development within the boundaries of several of its major drainage basins. As growth continues within these basins, the threat associated with flooding also grows. Flooding problems that presently exist will likely be exacerbated as future development occurs within these basins. Consequently, the construction of adequate storm drainage facilities that mitigate both existing and future flooding problems becomes increasingly important. In support of the need to provide these facilities, the Town contracted with Anderson Consulting Engineers, Inc. to develop a master drainage plan for those major drainage basins located within its urban growth management boundary. This report summarizes the results of the master planning efforts for these basins.

• Master Drainage Plan (Full Document) (PDF) 
• Cover and Table of Contents (PDF)
• Chapter 1 - Introduction (PDF)
• Chapter 2 - Basin Characteristics (PDF)
• Chapter 3 - Existing Facilities (PDF)
• Chapter 4 - Hydrologic Analysis (PDF)
• Chapter 5 - Drainage Improvements (PDF)
• Chapter 6 - Implementation Plan (PDF)
• Chapter 7 - Storm Impact Fees (PDF)
• Chapter 8 - Summary and Recommendations (PDF)
• A1 - Existing Condition (PDF)
• A2 - Future Condition (PDF) 
• A3 - Future Condition w/ Over Detention (PDF)
• A4 - Future Condition w/ Improvements (PDF)
• Appendix B - Sub Basin Peak Discharge (PDF)
• Appendix C - Financing Plan (PDF)
• Existing Facilities - Exhibit 1A (PDF)
• Existing Facilities - Exhibit 1B (PDF)
• Sub Basin Map - Exhibit 2A (PDF)
• Sub Basin Map - Exhibit 2B (PDF)

Master Drainage Plan Update - 2017 

The purpose of the 2017 Master Drainage Plan (MDP) effort was to update the 2003 MDP in high priority basins and also to update the financing plan.  Volume I of the 2017 MDP updates the Law Basin and Windsor Basin.  Volume II of the 2017 MDP updates the Fossil Creek (formerly Ptarmigan) and River Ridge Basins. The updated Implementation Plan and Finance Plan are documented in Volume III.  Please contact Engineering for SWMM models and any other back up documentation for the MDP not posted on this website.

• Volume I - Law & Windsor Basin Report (PDF)
• Volume I - Law & Windsor Basin Appendix (PDF)
• Volume II - Fossil Creek & River Ridge Basin Report (PDF)
• Volume II - Fossil Creek & River Ridge Basin Appendix (PDF)
• Volume III - Finance Plan (PDF)

Master Drainage Plan Update - 2017 - Addendum (April 2018)

An addendum to the 2017 MDP update was issued in April of 2018.  The addendum updated errors discovered in the Fossil Creek SWMM models and figures.  Additionally the addendum helped clarify information in Appendix Table B.3 so that it is more useful when reviewing proposed development.  Please contact Engineering for SWMM models and any other back up documentation for the MDP not posted on this website.

• Addendum - Master Drainage Plan Update - 2017 (PDF)