Site Drainage, Hydrology and 2D Flood Modeling

Real-estate developers of residential communities, commercial and mixed-use sites, hotels and resorts, their master planners and architects, and the treatment-plant vendors they choose. The best time to start is the master plan or permit stage, before the grading, drainage and sanitary layouts are fixed. Florida projects, and international projects including the Dominican Republic.

What we design

• Stormwater and site drainage. Grading, inlets, pipes, swales, retention and detention ponds, and outfalls, designed to carry runoff away from buildings, roads and neighbors.
• Hydrology and hydraulics. Rainfall, runoff and peak flows for the site and the land that drains onto it; pipe, channel and culvert capacity; tide or river levels at the outfall.
• 2D water-resources modeling. Integrated 1D/2D models that run pipes and channels together with water moving across the ground surface, including rain-on-grid models where rain falls on every cell of the terrain. Tools such as HEC-RAS 2D and EPA SWMM, chosen for the project and the reviewing agency.
• Flood-risk and minimum-grade studies. Where water goes in a design storm, how deep and for how long, and the finished-floor, road and pad elevations that keep buildings and access above it.
• Sanitary sewer, lift stations and force mains. Gravity collection, pump stations and force mains from the buildings to the treatment plant, sized for full build-out and for each phase.
• Treatment plant site integration (PTAR / WWTP). The plant pad, access, inlet and outlet connections, bypass and emergency overflow, and the plant's place in the grading plan. The treatment process itself is the plant vendor's design and responsibility.
• Treated-water reuse for irrigation. Storage, pumping and distribution of treated water to landscape and golf irrigation, with setbacks from water bodies and runoff control.

Why one package

On a development site the storm system, the sewer, the treatment plant and the irrigation share one grading plan and the same outfalls. Designed separately, they collide: a lift station in the low spot, an irrigation area draining into a swale, a plant pad below the flood level. Designed together, the site is graded once.

Florida projects

Site drainage and stormwater design, with calculations, for permit submittals to the local engineering review and, where required, the water management district. Sealed by a Florida-licensed Professional Engineer.

Dominican Republic and the Caribbean

In the Dominican Republic we work in collaboration with CODIA-registered Dominican engineers. The drainage, hydrology and sanitary design feeds the environmental impact study (EsIA) and the storm and sanitary sheets the construction license asks for. Under the Ministry of Environment's 2023 discharge rules, a development that does not discharge to a regulated public sewer treats its own wastewater, and storm drainage stays separate from sewage. Planning both from the first master plan saves redesign later. We work in English and Spanish.

What we need from you

The master plan or site plan; a topographic survey or terrain data (LiDAR or drone); the geotechnical report; the building layout with room or unit counts; any permit conditions already issued; and the treatment-plant vendor's data, if one has been chosen.

How the work runs

Fully remote, from your documents. No site visits: your surveyor and contractor confirm field conditions. The fee is fixed and in writing before you commit. Fixed fee, quoted the same business day.

Questions developers ask

What is 2D flood modeling, and when is it worth it?

A 2D model follows water across the ground surface, cell by cell, instead of only through pipes. It shows flow paths, depths and how long water stands across the whole site. It earns its cost on flat or low sites, sites with water coming in from upstream, coastal sites where tide or surge sets the outfall level, and large master plans where one model replaces many separate calculations.

What is rain-on-grid?

Rain is applied to every cell of the terrain model, so the model finds the flow paths on its own. It is useful where drainage areas are unclear or the ground is very flat.

Do you design the wastewater treatment plant?

No. The treatment process is the plant vendor's design and responsibility. We design what surrounds it: the sewer, lift stations and force mains into the plant, the pad and site connections, and the reuse line out of it.

Can you work on a project in the Dominican Republic?

Yes, in collaboration with CODIA-registered Dominican engineers, so the design fits Dominican rules and permit sheets. Send the master plan or site plan and we quote the same business day.

When should a developer bring you in?

At the master plan or environmental permit stage, before building pads, roads and the treatment-plant location are fixed. That is when grades and pipe routes are cheapest to change.