Below is a current list of registrants.
| Full Name | Company |
|---|---|
| Ken Nyhoff | City of Lakewood |
| Mark Nyhoff | Muller Engineering Company |
| Swirvine Nyirenda | City of Aurora |
| Deb Ohlinger | Olsson |
| Jordan Ollanik | Advanced Drainage Systems |
| Laurel Olsen-Horen | City of Boulder |
| Chris Olson | Wright Water Engineers |
| Richard Ommert | City of Aurora - Public Works |
| Heather Otterstetter | City of Westminster |
| Candice Owen | City of Boulder |
| Alan Pagan-Rivera | Calibre Engineering |
| Laura Page | Mesa County |
| Charlie Pajares | Jacobs |
| Greg Panza | HR Green, Inc. |
| Steven Parker | NV5 |
| Heather Pasch | AECOM |
| David Pasic | Town of Erie |
| Teresa Patterson | Mile High Flood District |
| Thuy Patton | Colorado Water Conservation Board |
| Chris Pauley | Galloway & Co. |
| Walter Pennington | Merrick & Company |
| Jill Piatt Kemper | City of Aurora |
| Jon Pink | COMPASS, AECOM |
| Kimberley Pirri | AECOM |
| Rachelle Plas | City of Thornton |
| Seth Plas | City of Westminster |
| Tracey Pond | City of Golden |
| Tyler Popp | Parsons |
| Mary Powell | CORVUS Environmental |
| Erin Powers | City of Colorado Springs, Water Resources Engineering Division |
| Joel Price | Murraysmith |
| David Primus | Western Colorado University |
| Jamie Prochno | U.S. Army Corps of Engineers |
| Brian Prunty | City of Rifle |
| Jeri Pulkinen | City of Arvada |
| Tyler Purvis | City of Brush! |
| Dave Pyle | City of Aurora |
| Mick Pyle | Bowman Construction Supply |
| Al Quintana | City of Thornton |
| Arielle Rainey | Colorado School of Mines |
| Derek Rapp | Peak Stormwater Engineering, LLC |
| Erika Rasmussen | Town of Mead |
| David Rausch | Adams County Public Works |
| Karen Reynolds | City of Greeley |
| Alejandro Riano | AECOM |
| Allison Rice | Felsburg Holt & Ullevig |
| Jeffrey Rice | El Paso County |
| Brad Richardson | City of Aurora - Public Works |
| Brad Robenstein | Douglas County Public Works Engineering |
| Josh Roberts | ECI Site Construction Management |