"Texas, often referred to as the Lone Star State, is a thriving hub for economic growth and innovation, making it an attractive destination for commercial real estate investment." - Chris Evans

Hydrographic Surveys: Mapping Waterways for Commercial Development

When most people think of commercial real estate surveys, they picture land-based measurements of boundaries, easements, or construction layouts. But for developments near rivers, lakes, ports, or coastal areas, the water environment can be just as important as the land.

That’s where hydrographic surveys come in. These specialized surveys map bodies of water and underwater features, providing critical data for flood control, infrastructure design, and waterfront development. In Texas, where flooding and water management are ongoing challenges, hydrographic surveys are increasingly valuable for commercial projects.

In this blog, we’ll explain what hydrographic surveys are, how they’re conducted, why they matter in commercial real estate, and how they support safe, sustainable development.

What Is a Hydrographic Survey?

A hydrographic survey measures and maps the physical features of bodies of water and the land beneath them. It is essentially a “topographic survey of water,” used to understand depth, contours, currents, and related conditions.

Hydrographic surveys typically measure:

• Water depth (bathymetry).

• Shorelines and banks.

• Riverbeds, lakebeds, or seabeds.

• Currents and flow patterns.

• Sediment buildup.

• Flood control channels.

• Submerged structures or hazards.

Why Hydrographic Surveys Are Important in Commercial Real Estate

1. Flood Management

Hydrographic data informs floodplain studies, drainage design, and stormwater management systems.

2. Waterfront Development

Hotels, marinas, warehouses, and industrial facilities near water require hydrographic surveys for permitting and design.

3. Infrastructure Planning

Bridges, dams, and pipelines crossing water bodies rely on hydrographic surveys for foundation design and risk assessment.

4. Environmental Compliance

Hydrographic surveys document wetlands, erosion, and aquatic habitats to meet environmental regulations.

5. Risk Mitigation

Identifying sediment buildup, shallow areas, or unstable banks prevents costly surprises during development.

The Hydrographic Survey Process

Step 1: Preliminary Research

Surveyors gather charts, FEMA maps, and prior hydrographic data.

Step 2: Field Measurements

Tools like echo sounders, sonar, and GPS collect depth and location data.

Step 3: Shoreline Mapping

Surveyors map the transition between land and water, often integrating with topographic surveys.

Step 4: Data Processing

Collected points are compiled into bathymetric charts and 3D terrain models.

Step 5: Reporting and Deliverables

Final reports include maps, charts, and certifications for engineers, developers, and permitting agencies.

Tools and Technology Used in Hydrographic Surveys

• Single-beam echo sounders – Measure depth along survey lines.

• Multi-beam sonar – Capture wide swaths of depth data for 3D mapping.

• Side-scan sonar – Identify underwater features and hazards.

• GNSS GPS positioning – Provide precise georeferencing of measurements.

• Drones and UAVs – Capture shoreline data to merge with bathymetric results.

Common Issues Revealed by Hydrographic Surveys

• Sediment buildup restricting water flow.

• Erosion along riverbanks and shorelines.

• Shallow areas creating navigation hazards.

• Drainage channel obstructions.

• Inaccurate floodplain boundaries compared to FEMA maps.

Hydrographic Surveys vs. Other Survey Types

• Topographic Surveys – Map land elevations, but not water depths.

• Floodplain Surveys – Compare land elevations to FEMA flood maps.

• Environmental Surveys – Assess wetlands and habitats, but not detailed water depths.

• Hydrographic Surveys – Focus on underwater mapping and hydrological data.

Each survey type provides unique insights, but together they give developers a full picture of land-and-water interactions.

Hydrographic Surveys in Texas

Texas has unique challenges that make hydrographic surveys especially important:

• Houston’s bayous and floodplains create ongoing flood risks.

• The Gulf Coast requires hydrographic data for ports, pipelines, and refineries.

• Reservoirs and lakes like Lake Conroe and Lake Houston need sediment monitoring for water supply and recreation.

• Rapid growth in waterfront commercial projects requires environmental and flood compliance.

For developers, hydrographic surveys are a crucial step in ensuring projects are safe, compliant, and resilient against water-related risks.

Cost of Hydrographic Surveys

Several factors influence cost:

• Size of the water body.

• Type of technology used (single-beam vs. multi-beam sonar).

• Level of detail required.

• Integration with land-based surveys.

Basic hydrographic surveys may cost a few thousand dollars, while large-scale port or flood-control projects can cost much more.

Why Developers Shouldn’t Skip Hydrographic Surveys

• Prevents inaccurate floodplain assumptions.

• Reduces risk of permitting denials.

• Protects infrastructure investments.

• Ensures compliance with FEMA, EPA, and state regulations.

• Provides confidence to lenders and insurers.

In short, a hydrographic survey is a small upfront cost compared to the long-term risk of ignoring water-related data.

The Future of Hydrographic Surveys

Technology is rapidly expanding the usefulness of hydrographic surveys:

• Autonomous survey vessels collecting real-time sonar data.

• LiDAR bathymetry from aircraft for shallow-water mapping.

• AI-driven flood modeling integrating survey data with predictive analytics.

• Digital twins combining land and water data for advanced urban planning.

Hydrographic surveys may not be as widely known as boundary or ALTA surveys, but they are just as critical—especially for commercial projects near water. They provide essential data on depths, currents, and underwater conditions that shape design, permitting, and risk management.

In Texas, where water management and flood control are central to commercial growth, hydrographic surveys are an indispensable tool. For developers, investors, and municipalities, they ensure projects are safe, sustainable, and resilient against water-related challenges.