Below is a current list of registrants.
| Full Name | Company |
|---|---|
| Nathan Seymour | Jefferson County - Planning and Zoning |
| Katy Shaneyfelt | Muller Engineering Company |
| Jeffrey Sickles | Enginuity Engineering Solutions |
| Jeron Siegert | ECI Site Construction |
| John Sikora | AECOM |
| Jeff Simonson | SGM |
| Matt Simpson | Ayres Associates |
| Robert Singer | Kleinfelder |
| David Skuodas | Urban Drainage and Flood Control District |
| George Slovensky | City of Aurora |
| Shannon Smith | Town of Breckenridge |
| Kurt Smithgall | S2o Design and Engineering |
| Angela Snyder | Weld County Planning |
| Brent Soderlin | Jefferson County |
| Roger Sorge | City of Denver Wastewater |
| Nate Soule | Lithos Engineering |
| William Spitz | Olsson Associates |
| Garrett Sprouse | CDM Smith |
| Kenneth Kelly Stallworth | Town of Estes Park |
| Liz Staten | HDR |
| Curtis Stevens | The Sanitas Group |
| Jessica Stevens | City of Boulder |
| Kevin Stewart | Urban Drainage and Flood Control District |
| Britta Strother | Stantec |
| Chris Sturm | Colorado Water Conservation Board |
| Betsy Suerth | City of Delta |
| Aaron Sutherlin | Matrix Design Group |
| David Sutley | DHS FEMA Region VIII |
| Christine Sveum | Atwell |
| Brinton Swift | Kiewit Infrastructure Engineers |
| Chris Tagert | Michael Baker International |
| Jesse Tatum | HDR |
| Alan Taylor | Alan Taylor Consulting, LLC |
| Mark Taylor | The Architerra Group |
| Phillip Taylor | Hydro International |
| Ryan Taylor | Muller Engineering Company |
| Britton Thomas | J3 Engineering Consultants, Inc. |
| Paul Thomas | Stream Landscape Architecture |
| Shea Thomas | Urban Drainage and Flood Control District |
| Stacey Thompson | SEMSWA |
| Brenden Tippets | Michels Corporation |
| Phillip Todd | North State Environmental |
| Shawn Tracy | HR Green, Inc. |
| Tony Tran | City of Aurora - Aurora Water |
| Julia Traylor | Wright Water Engineers |
| Molly Trujillo | SEMSWA |
| Alan Turner | Jacobs |
| Geoffrey Uhlemann | AECOM |
| Matt Ursetta | ICON Engineering, Inc. |
| Glenn Van Horn | Basalite Concrete Products, LLC |