Below is a current list of registrants.
| Full Name | Company |
|---|---|
| Susan Pearson | Town of Silverthorne |
| Riley Pennington | City of Arvada |
| Walt Pennington | Respec |
| Craig Perl | City of Aurora |
| Jenna Phillips | Muller Engineering Company |
| Jon Pink | AECOM/COMPASS |
| Kimberley Pirri | AECOM |
| Holly Piza | Urban Drainage and Flood Control District |
| Rachelle Plas | City of Thornton |
| Seth Plas | City of Westminster |
| Mary Powell | CORVUS Environmental |
| Alex Powers | Contech Engineered Solutions LLC |
| Erin Powers | City of Colorado Springs, Water Resources Engineering |
| Joel Price | Murraysmith, Inc. |
| Jamie Prochno | USACE Omaha District |
| Brian Prunty | City of Rifle |
| Tyler Purvis | City of Brush! |
| Mick Pyle | Bowman Construction Supply Inc. |
| Al Quintana | City of Thornton |
| Katie Radavich | SGM |
| Kayla Ranney | HDR |
| Derek Rapp | Peak Stormwater Engineering, LLC |
| Erika Rasmussen | Town of Mead |
| Lanae Raymond | SEMSWA |
| Taylor Reeves | Ware Malcomb |
| Josh Rice | Woody Creek Engineering, LLC |
| Lon Robbins | Kiewit Infrastructure Engineers |
| Dusty Robinson | Ayres Associates |
| Joseph Roerkohl | AECOM |
| Josh Root | Stanley Consultants |
| Tyler Rosburg | ICON Engineering, Inc. |
| Jeanie Rossillon | Jefferson County |
| Rigel Rucker | AECOM |
| Brian Rustia | ADS/BaySaver |
| Thom Rutledge | Jacobs |
| Steve Salazar | Wilson & Company, Inc. |
| Scott Samuels | Mesa County |
| David Samuelson | Town of Telluride |
| John Santos | AquaShield, Inc. |
| Mike Sasarak | City and County of Denver |
| Erik Saunders | City of Boulder |
| Megan Sawyer | Matrix Design Group |
| Chuck Schrader | Pinyon Environmental, Inc. |
| Matt Schram | David Evans and Associates |
| Scott Schreiber | Wright Water Engineers |
| Steven Scott | Hanes Geo Components |
| Traci Sears | Montana DNRC Floodplain Program |
| Heather Seitz | City of Greeley |
| Timothy Semones | City of Thornton |
| Brooke Seymour | Urban Drainage and Flood Control District |