Section 2: Introduction to Hydraulic Analysis and Design
The involvement of hydraulic engineers from the Design Division or at the district level should ideally begin in the project initiation phase of a project. In some cases such early involvement may not be justified or feasible. In all projects requiring any significant input from hydraulics, input should start no later than the beginning of planning phase. Hydraulic engineering input at the earliest stages of the project can help the project manager to anticipate important project elements that could impact the project cost or schedule. Examples of such elements include but are not limited to the following:
- Anchor: #RLLGIJEM
- Regulatory elements, such as National Flood Insurance Program (NFIP) floodways, that could impose significant constraints, Anchor: #QLJNHMEG
- Existing drainage structures (such as culverts) that are hydraulically inadequate and which may require complete replacement rather than mere extension as part of a widening project, Anchor: #PLIKHENK
- Opportunities to avoid complete replacement of drainage structures through various types of rehabilitation, Anchor: #OLHHGHNE
- Fundamental hydraulic or stream stability problems at a proposed new stream crossing location, Anchor: #LGEFKMIN
- Upcoming or ongoing flood control projects by other parties that could improve or alter the drainage situation at a given location.
Hydraulic engineering expertise can be applied to a broad range of aspects of a TxDOT project including environmental documentation and mitigation, cross-drainage design, pavement drainage and storm drain design, detention facilities, storm water quality best management practices, and regulatory compliance. The types of projects requiring or benefiting from hydraulics input include:
- Anchor: #NKLGKEHN
- Highway widening or reconstruction Anchor: #KQHEJNLG
- Urban street reconstruction Anchor: #GRHFNEIH
- Intersection improvements Anchor: #MSHHGFFH
- Interchange addition or modifications Anchor: #KRKLIENJ
- Bridge replacements Anchor: #KHIKMLFK
- Constructing routes on new alignments Anchor: #KNJLEEGH
- Safety improvement projects Anchor: #LJKLFHHE
- Chronic maintenance problem remediation Anchor: #MFLLGKHL
- Pump stations Anchor: #MLMLHNII
- Storm water quantity and quality control systems.
The hydraulic design or analysis of highway drainage facilities usually involves a general procedure, the specific components of which vary for each project. Some of the basic components inherent in the design or analysis of any highway drainage facility include data, surveys of existing characteristics, estimates of future characteristics, engineering design criteria, discharge estimates, structure requirements and constraints, and receiving facilities.
Time, expense, focus, and completeness of the design or analysis process should all be commensurate with the relative importance of the facility, that is, its cost, level of use, public safety, impact to adjacent lands, and similar factors. These aspects of the design process are often subjective. The funding or time constraints associated with any engineered project often are determining factors in the designer’s involvement.