Professional hydrology and hydraulic analysis services for residential, commercial, and municipal development projects across Texas. Our licensed civil engineers perform hydrologic modeling, hydraulic analysis, flood studies, and stormwater calculations using HEC-HMS, HEC-RAS, and industry-standard software to support drainage design, floodplain analysis, and permit applications throughout the Houston metropolitan area.
Our Hydrology & Hydraulics Services
Hydrologic Modeling (HEC-HMS)
Hydrologic modeling using HEC-HMS to calculate peak flows, runoff volumes, and hydrographs for drainage design and flood analysis.
Hydraulic Modeling (HEC-RAS)
Hydraulic modeling using HEC-RAS for water surface profile analysis, floodplain delineation, and channel/culvert capacity analysis.
Peak Flow & Runoff Calculations
Calculation of peak discharge and runoff volumes using rational method, SCS curve number method, and unit hydrograph methods.
Floodplain Analysis & Mapping
Floodplain analysis and delineation including base flood elevation determination and FEMA flood zone mapping.
Drainage Area Analysis
Delineation and analysis of drainage areas, sub-basins, and contributing watersheds for site development and flood studies.
Stormwater Routing Analysis
Hydrograph routing through detention basins, channels, and pipe networks to verify stormwater storage and release rates.
No-Rise Studies
Hydraulic studies demonstrating no floodway impact for proposed development in regulatory FEMA floodways.
Drainage Impact Analysis
Analysis of pre- and post-development drainage conditions to assess project impacts and design appropriate mitigation.
When hydrology and hydraulic analysis may be needed
Hydrology and hydraulic analysis may be needed for drainage design, detention sizing, floodplain studies, no-rise analyses, drainage impact assessments, and permit applications. ALFA's licensed civil engineers perform runoff analysis and hydraulic conveyance analysis to support project design and agency review.
Runoff analysis (hydrology) determines how much stormwater runoff a site or watershed produces — peak flows, runoff volumes, and hydrographs. Hydraulic conveyance analysis determines how that runoff moves through channels, pipes, culverts, and floodplains — water surface elevations, velocities, and capacity. The two are related but answer different questions; a project may need one or both depending on the scope and the reviewing agency's criteria.
Project steps
- 1Data & scope review — ALFA reviews available survey, topographic, drainage, and modeling information against the study purpose and the reviewing agency's criteria.
- 2Hydrologic analysis — drainage areas, runoff characteristics, peak flows, and hydrographs are developed using methods appropriate to the project and the agency's criteria.
- 3Hydraulic analysis — conveyance through channels, pipes, culverts, or floodplains is analyzed for capacity, water surface elevation, and velocity as needed.
- 4Documentation & submittal — ALFA prepares the modeling, calculations, and supporting documentation, and coordinates the submittal with the reviewing agency; the authority having jurisdiction makes the final determination.
The applicable methods, models, and design storms are set by the reviewing jurisdiction and depend on project conditions such as drainage area, location, flood zone, and downstream conditions. ALFA uses HEC-HMS for hydrologic modeling and HEC-RAS for hydraulic modeling where the project and agency criteria call for them. ALFA does not publish generic design storms or methods and does not guarantee agency acceptance. Methods and criteria for your project are confirmed with the applicable jurisdiction.
Information needed for a quote
- Property address
- Study purpose (drainage design, detention, floodplain, no-rise, drainage impact, etc.)
- Survey or topographic information (if available)
- Existing drainage information or prior studies
- Existing models (if available)
- Agency or reviewer comments (if available)
You don't need all of these to start the conversation. Share what you have and ALFA will help identify what else is needed for your proposal.
Availability: Hydrology and hydraulic analysis is available statewide. On-site visits, when included in the agreed scope, are scheduled based on project location.
How to Request a Proposal
Use the button below to request a proposal. Describe your project, site address, and any specific concerns or requirements.
Related Engineering Services
Drainage Design
Site drainage, stormwater conveyance, and detention for Texas projects.
Detention Pond Design
Stormwater detention sizing, routing, and outlet structure design.
Floodplain Engineering
FEMA LOMA/LOMR, no-rise studies, and floodplain compliance.
Stormwater Management
Stormwater detention, retention, quality BMPs, and MS4/TCEQ compliance.
Scope of Services
Related Services
Related Tools & Official Resources
Verify requirements with the official government sources before your project — these verified resources and plain-English answers apply directly to this service.