Committee on Design

AASHTO Liaison
Patricia Bush, Program Manager for Engineering

Technical Committee on Hydrology and Hydraulics

TCHH Membership
Membership on the TCHH is limited to the AASHTO Member Departments, which consist of the transportation departments of the 50 states, the District of Columbia, and Puerto Rico.  When a vacancy occurs, nominations are made by each state’s Committee on Design members within that region, and appointments are made by the Committee on Design Chair.  Currently each of the 4 AASHTO Regions are represented by 5 TCHH members.  TCHH members do not need to be members of the Committee on Design.

Objective and Scope
The objective of this technical committee is to provide a focal point and working group with expertise in hydrology and hydraulics to develop AASHTO guidelines and policies for drainage design of transportation facilities.

State Comments and Questions
TCHH continuously solicits input from non-TCHH member states to improve the application and understanding of Hydraulic Engineering within linear transportation environments. Send research ideas, Drainage Manual questions/suggestions, or “hot topic” concerns applicable to Hydraulic Engineering to the TCHH chair, Jeff Syar (contact information below).

Publication Responsibility

AASHTO Drainage Manual, 1st Edition (CD-ROM) 

AASHTO released the AASHTO Drainage Manual, 1st Edition, which replaces the AASHTO Model Drainage Manual, published in 2005.

The technical committee is responsible for updating the Highway Drainage Guidelines, 4th Edition. 

For more information about either of these publications, or to purchase a copy, visit the AASHTBookstore at


This newsletter is published biannually by TCHH.  To be added or removed from the mailing list, to suggest articles, or to provide comments, contact Andrea Hendrickson (contact information below).

Issue 19 – Fall 2020

Issue 18 – Fall 2019

Issue 17 – Winter 2019

Issue 16 – Winter 2018

Issue 15 – Summer 2017

Issue 14 – Winter 2016

Issue 13 – Summer 2016

Issue 12 – Winter 2015

Issue 11 – Summer 2015

Issue 10 – Winter 2014

Issue 9 – Winter 2013


TCHH members actively promote, solicit, and participate in national and state hydraulic engineering research.  TCHH collaborates and coordinates with committees of the Transportation Research Board (TRB) and state DOTs to develop research need statements applicable to hydraulic engineering for funding through the National Cooperative Highway Research Program (NCHRP).

This document contains active and completed research that TCHH is aware of pertaining to hydraulic and stormwater engineering.

TCHH maintains a Strategic Research Plan (SRP) to maximize the impact of hydrology and hydraulic research efforts to address critical needs and gaps in knowledge.  The SRP is reviewed on an annual basis to ensure it remains relevant and applicable to current understanding and need.  This SRP includes guidance for RNS submitters who are seeking AASHTO endorsement.  The current SRP can be found here.

Useful Links

TRB Snap Search: Hydraulics & Hydrology –

FHWA Bridges and Structures: Hydraulic Engineering –

TCHH Membership

Committee Name:
COD-Technical Committee on Hydrology and Hydraulics
Sort By:
Individual Name
Email Address
Agency Name
Member Type

For questions or comments relating to this committee, please contact Patricia Bush

Back to Top