Environmental and Water Resources Institute


The Environmental and Water Resources Institute (EWRI) was created on April 6, 1995 as a technical subcommittee of the Arizona Society of Civil Engineers (AzSCE).

January 2016 Breakfast meeting presentation October 2015 Breakfast Meeting – Ocotillo Brine Reduction Facility Tour
January 2016 Breakfast Meeting Presentation October 2015 Breakfast Meeting – Ocotillo Brine Reduction Facility Tour

April Breakfast Meeting

Date:  Thursday, April 20th @ 7:15 AM, * Presentation Begins at 7:30 AM.


Carollo Engineering, Inc. 4600 East Washington Street, Suite 500, Phoenix, Arizona, 85034 (MAP)

Parking: There are several visitor parking spaces on the first floor of the parking garage (just north of the building, between the building and the American Family Insurance Building). If the gate is open you can also park on the roof of the parking garage.

Building Access: The main doors to the building are locked until 8:00AM, a security guard is generally at the entrance and will let you in, just say you are going to Carollo for the EWRI breakfast meeting. Inside take the elevator to the 5th floor (the door to the stairs is generally locked on the 5th floor). Follow the signs for the EWRI meeting.


Dennis L. Richards, P.E., D.WRE, F.EWRI, F.ASCE of Premier Engineering Corporation

Dennis has more than 46 years of experience in hydraulic and sedimentation engineering. He earned an M.S. in Civil Engineering from South Dakota State University in 1970 with an emphasis in fluvial hydraulics. He has managed the hydraulic and scour analyses for more than thirty bank stabilization projects and for numerous bridges. Dennis has presented workshops on scour analysis for streambank stabilization; and the hydraulic design of channels, culverts, and energy dissipators throughout the U.S. He has also managed the development of State Standards for Floodplain Management: a) Watercourse System Sediment Balance; b) Watercourse Bank Stabilization; and c) Floodplain Hydraulic Modeling.

Dennis is active in EWRI where he has championed the development of EWRI Chapters over the past 16 years. He currently serves as Chair of the Management Practices for Erosion and Sediment Control Standards Committee; Vice-Chair of the Technical Products and Modernization Committee; Secretary of Local Activities Council, and a member of the Standards Development Council. Dennis is the 2017 recipient of the EWRI Service to the Institute Award.


Scouring the Regime Equations

The presentation will focus on the various equations available for predicting general scour. In particular, the background and limitations associated with the regime equations developed by Lacey and Blench, which were based primarily on data from canal systems in India will be presented. The equations as developed by Lacey in 1931 and Blench in 1969 will be compared with the equations as published in technical guidelines and design manuals. The presentation will also discuss Neil’s regime equation for predicting general/contraction scour as well other methods/equations for predicting general and contraction scour. The presentation will also include case studies to demonstrate results obtained through application of the various methods.

BREAKFAST SPONSOR: Premier Engineering Corporation

Please let us know if you are interested in sponsoring breakfast for a future meeting.

RSVP:  Please respond to Josh Papworth (josh.papworth@dibblecorp.com) by 5:00 PM Wednesday, April 19th if you plan to attend.


Ocotillo Brine Reduction Facility Tour

City of Phoenix Rio Salado Project Tour

Committee’s Mission:

“Provide an open forum for discussing technical water resource issues within Arizona.”

Objectives of the EWRI include:

  • Conducting technical education programs on water resource topics
  • Sponsoring activities that serve the need of water resource professionals
  • Furthering public understanding of the field of water resources, hydraulics, and environmental engineering
  • Coordinating local water resource related functions with other related organizations
  • Review and comment on state and local legislation related to water resource issues

The Committee meets monthly to hear presentations and discuss technical water resource issues, studies, and projects. Field trips are occasionally offered to allow participants to witness firsthand how local water resource issues and challenges are being addressed.

Past Committee Activities:

  • Monthly technical presentations on current water resource topics
  • Field trips to local water resource projects
  • Coordination of technical sessions at AzSCE conferences
  • Assisting other local water resource organizations with their functions and workshops
  • Serving as local host in 1999 for the American Society of Civil Engineers (ASCE) Water Resources Planning and Management Division’s 26th Annual Conference, held in Tempe
  • Assisting with local ASCE sponsored workshops on Urban Stormwater Management, HECRAS, etc.

The group’s bylaws were adopted in 1995 and are available from the Committee’s Secretary or can be downloaded here (14 KB, PDF).
They address the following:

  • Officers: Chairman, Vice Chair, Secretary, and Past Chairman.
  • Membership: Any subscribing member of the AzSCE who submits a written request for membership shall be considered a member.
  • Annual Business Meeting: Held on or before October 31.

Because the EWRI is sanctioned by the ASCE, committee membership requires membership in ASCE. However, non-ASCE members are welcome to attend committee meetings and events. There are no dues, other than those normally paid by members of the ASCE. To request an ASCE membership application, please contact the ASCE at (800) 548-2723 or online at www.asce.org.

To Become a Member of the EWRI:
To become a member of and/or receive information about the EWRI Arizona Chapter, please complete the following information:

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Privacy Notice: Your name, e-mail address, and other information collected will be held in strict confidence and will not be sold or shared with any other group or organization, and will not be used for any purpose other than providing information to you regarding the AzSCE Water Resources Technical Committee.

AzSCE EWRI Officers:

Jonathon Chill, Chair (jchill@carollo.com)
Ed Kern, Vice-Chair (Ed.Kern@helm.world)
Josh Papworth, Secretary (Josh.Papworth@dibblecorp.com)
Janelle Moyer, Past Chair (Janelle.Moyer@hdrinc.com)
Frederick Tack, EWRI National Liaison (Frederick.Tack@ghd.com)