DRAINAGE ENGINEERING

Communities are increasingly focused on the impacts of stormwater and the importance of managing it in a comprehensive, sustainable way.

For decades, HLR has helped local, county, and state agencies develop drainage solutions that protect water quality, safeguard property, and enhance community safety.


Every project is approached with careful consideration of location, land availability, regulations, and design requirements to deliver solutions that align with client needs and budgets. Through advanced and proven stormwater technologies, HLR provides comprehensive drainage studies, hydraulic models, and detailed construction plans for storm sewer systems, sustainable applications, and erosion control measures.



Expertise also extends to pump station analysis, detention basin design, and water quality Best Management Practices (BMPs). In addition, HLR’s familiarity with funding agencies positions clients for success when seeking project grants and loans.

  • STORMWATER MODELING AND MASTER PLANS

    Hydrologic and hydraulic modeling allows us to produce conceptual representations of watersheds and predict how storm events will impact communities. Stormwater master plans can also be produced using these models. They provide a roadmap for successful rainfall event management and help isolate and prioritize problem areas. We have worked with many municipalities to develop and implement these plans and can help you with your stormwater issues.

  • WATER DETENTION / RETENTION STRUCTURES

    Stormwater conveyance systems are often overburdened due to under-designed detention systems. This causes existing pipes to fill and surcharge during rainfall events and inundate some areas, causing unsafe conditions. Our drainage professionals design stormwater regulation compliant above- and below-ground detention and retention basins while keeping in mind aesthetics, grading, and project footprint. This helps protect upstream and downstream residents and businesses who would be affected by flood events.

  • VOLUME CONTROL SOLUTIONS

    Volume control helps to reduce continued pressure on overland routes to convey stormwater. These measures help to promote infiltration and groundwater recharge in a manner similar to pre-development conditions. Our engineers utilize environmentally-friendly methods to increase infiltration of stormwater into soils including infiltration trenches, rain gardens, dry wells, and native vegetation.

  • FLOODPLAIN / FLOODWAY ANALYSIS

    Modeling of existing floodplains/floodways is an important aspect of what we do at HLR. If a change has occurred or is anticipated, our specialists have the ability to determine the possible impacts, positive or negative, to the base flood elevation. This allows communities and landowners to understand potential flooding issues and how local and state regulations limits impact development activities.

  • FLOOD INSURANCE CERTIFICATES

    Flood Insurance Rates keep rising and annual cost to homeowners may approach unaffordable limits. By providing your insurance agent with an elevation certificate, it may reduce your premium or even relieve you from the obligation of flood insurance. Our drainage and survey specialists prepare these certificates regularly which also helps reduce flood insurance premiums for specific residences or businesses.

  • FEMA MAP REVISION

    Many communities participate in the National Flood Insurance Program (NFIP). However, keeping flood maps up-to-date is a challenge since they require regular revisits to ensure accuracy for floodplain management and insurance rating. Our drainage professionals take on this responsibility for many of our clients and help delineate Zone A floodplains or re-evaluate existing floodways based on new data or stormwater management project implementation.

  • PERMITTING

    Permitting requirements and applicable stormwater regulations are essential. They help protect property, the natural environment, and the public against damage or safety concerns from flooding and pollution. At HLR, we identify specifically what permits are required in order to comply with local, county, state, and federal ordinances. We use the benefit of our experience and existing relationships to expedite this process so projects progress in an efficient and cost-effective manner.

  • LOCATION DRAINAGE STUDIES AND HYDRAULIC REPORTS

    If your project involves a state route or funding, then you will likely be required to prepare a Location Drainage Study for a roadway improvement or a Hydraulic Report for a bridge/culvert replacement/modification. HLR has extensive experience preparing the necessary IDOT documentation for these types of projects, ultimately expediting the process and reducing the amount of comments received.