Stormwater Management Services


When the Water’s Rising, We Will
Help Keep Your Feet Dry

LAN offers the complete spectrum of stormwater management services, including initial planning and feasibility studies, experienced design engineering and construction support, and permitting and regulatory compliance.

2-Dimensional (2D) Modeling

2D hydrodynamic modeling has become a powerful tool to investigate areas impacted by flooding during rainfall events. By modeling historic rainfall events, 2D modeling helps accurately demonstrate rainfall depth and flow direction. Our 2D modeling specialists apply practical modeling techniques to fully understand stormwater conveyance system performance during flood events, identify the root cause of flooding problems, develop solutions on localized and regional scales, and document improvement benefits.

Water Quality Management & Modeling

With more communities experiencing substantial population growth, urbanization, and aging infrastructure, receiving water bodies are becoming increasingly polluted by urban runoff and wastewater leaks. The LAN team has developed water quality tools to quantify the cost and effectiveness of proposed water quality improvement measures. Our water quality team can work directly with communities and agencies to address existing impairments, as well as guide future watershed planning to improve sustainability and quality of life.

Thermal Modeling

Cooling water discharged from power plants and industrial facilities may have negative impacts on receiving water bodies and ecosystems. Our thermal modeling team has the tools and extensive experience to evaluate and address thermal discharge issues, as well as support the permitting process with regulatory agencies. We are knowledgeable of current and impending state and federal regulations and can assist affected industries with technical support to meet or maintain compliance.

Municipal Separate Storm Sewer (MS4) Permitting

The Clean Water Act is the primary federal law that regulates water pollution to surface waters and requires most municipalities have an MS4 permit to regulate stormwater discharges. LAN can support a variety of compliance obligations, including:

  • Permit application
  • Storm Water Management Plan (SWMP) / Storm Water Pollution Prevention Plan (SWPPP) development
  • Best Management Practice (BMP) creation and implementation

We are knowledgeable of existing and emerging stormwater quality regulations and have a proven track record of keeping clients in compliance.

Community Rating System (CRS)

CRS is a flood insurance premium discount program for communities in the National Flood Insurance Program (NFIP) to adopt and enforce higher standards for better floodplain management. LAN provides assistance in all areas of the CRS process, including new CRS applications, verification, program optimization, and individual activities within the CRS program.


LAN has experience with Municipal Separate Storm Sewer System (MS4) stormwater discharge permits, stormwater construction permits and industrial stormwater activities.
LAN developed a county-wide master plan covering all 2,500 miles of channel in Harris County, Texas.

Stormwater Management Leadership

LAN Yu Chun Su
Senior Associate, Technical Director, Environmental & Water Resources Engineering
LAN Matt Manges
Matt Manges, PE, CFM, ENV SP
Vice President, Practice Leader
LAN Janine Ellington
Janine Ellington, CFM
CRS/Floodplain Programs Manager
LAN Laura Casset
Laura Casset, PE, CFM, CPESC
Associate, Regional Stormwater Manager
Example Projects