Introduction

Large‑diameter stormwater pipes and roadway/rail culverts (36–120 inches) in Florida and the broader Southeast routinely suffer from corrosion, joint failures, flotation, and loss of invert due to abrasion and tidal/surge conditions. Hinterland Group delivers trenchless rehabilitation at these sizes using three core methods performed in‑house: CIPP liner installation, spray‑applied geopolymer lining (SAPL/SIPP), and sliplining. Programmatically, this page supports and is linked from Pipe Rehabilitation.

Diameter bands and method fit

The matrix below summarizes method selection by inner diameter band, typical drivers, and practical fit. Final design is project‑specific and validated by inspection data and engineering calculations.

Diameter band	Primary method(s)	Typical drivers	Practical fit notes
36–54 in	CIPP; SAPL/SIPP	I/I control, corrosion, ovality under traffic loads	CIPP well‑suited for continuous runs; SAPL adapts to irregular shapes and localized wall loss.
60–84 in	CIPP; SAPL/SIPP; Sliplining	Structural renewal, tidal surcharge, abrasion at invert	CIPP available to large diameters the company installs across the Southeast; SAPL builds thickness at inverts; sliplining used where upsizing not required and annular grouting is feasible.
90–120 in	CIPP; SAPL/SIPP	Full structural renewal of CMP/RCP, critical crossings	CIPP applied on major assets noted in company casework; SAPL advantageous for non‑circular/elliptical or structurally complex geometries.

Hinterland performs all trenchless technologies in‑house and recommends method after condition assessment; see Pipe Rehabilitation and Inspection.
Regional large‑diameter experience includes CIPP capabilities up to 108 inches as described on regional service pages (e.g., CIPP Florida, CIPP Georgia, CIPP South Carolina).

Method selection details

Cured‑In‑Place Pipe (CIPP)

Ideal for continuous circular or oval runs with widespread defects (corrosion, joint separation, infiltration) where a structural liner will create a new pipe inside the host with minimal excavation.
Frequently restores structural capacity while improving hydraulic smoothness; installation and curing are coordinated with bypass or flow control plans when needed.
Large‑diameter capability up to 108 inches is referenced on Hinterland’s regional pages; see CIPP Florida and CIPP Georgia.

Spray‑Applied Geopolymer Lining (SAPL/SIPP)

Best for irregular geometries, wide egg/elliptical sections, or when rebuilding inverts and addressing localized wall loss without reducing diameter significantly.
Enables targeted thickness where loads and abrasion are greatest (e.g., tidal or high‑velocity reaches) while maintaining cross‑section.

Sliplining

Used where host condition allows insertion of a new, smaller carrier pipe with annular grouting; valuable for long straight segments and when a homogenous new pipe is preferred.
Considered when ultra‑smooth hydraulics offset diameter reduction or when constructability (access, curvature) favors inserted carrier pipe.

Hydraulics and flow restoration (modeled examples)

The following examples illustrate how smoother rehabilitated surfaces can offset or exceed any reduction in diameter. They use standard Manning relationships for full‑flow comparison with constant slope and are provided for scoping only; actual results require project‑specific hydraulic modeling based on cleaned/pre‑rehab conditions and survey data.

Example A (CMP to CIPP): 60‑inch corrugated metal pipe (assume n≈0.024) rehabilitated with a CIPP liner reducing ID by ~2 inches and achieving a smooth interior (assume n≈0.012). Estimated capacity change: roughly +80% under full‑flow assumptions, despite minor diameter reduction.
Example B (RCP to SAPL): 72‑inch reinforced concrete pipe (assume pre‑rehab n≈0.013) with a thin geopolymer build that minimally reduces diameter and maintains n≈0.013. Estimated change: roughly −4% due to slight cross‑section loss; performance gains often realized via restored shape, joint sealing, and invert rebuilding under partial‑flow/tidal conditions.
Example C (Slipline): 60‑inch host sliplined with a 54‑inch smooth carrier (assume n≈0.011). Estimated capacity change: roughly +60% under full‑flow assumptions when comparing rough host to smooth carrier; verify downstream controls and partial‑flow dynamics.

Guidance: validate hydraulics with post‑cleaning CCTV and survey, then finalize design with flow management planning. See Inspection and Maintenance Plans.

Florida stormwater and culvert examples

Charlotte County Stormwater Collection System Rehabilitation: referenced among inspection‑supported projects demonstrating stormwater system rehab and QA/QC workflows. See related work on Inspection.
West Palm Beach 31–35th Street Water Main and Drainage Project (~$4M): multi‑street utility and drainage improvements serving ~170 homes, illustrating coordination in dense urban corridors. See project page: 31–35th Street Water Main and Drainage Project.
Nottingham Boulevard and Miller Avenue Area (City of West Palm Beach, ~2021): integrated water, sewer, and drainage improvements including CIPP lining of existing sanitary pipe and substantial roadway restoration—indicative of complex traffic and restoration management common to culvert rehabilitations. See Nottingham Water, Sewer & Drainage Improvements.
Martin County Emergency Flooding Services: emergency storm response and bypass capabilities relevant to culvert failures and surge events. See Martin County Emergency Services.

Note: Additional large‑diameter stormwater and culvert projects are available on the portfolio and case study pages; see Case Studies.

What Hinterland provides for large‑diameter assets

In‑house trenchless portfolio (CIPP, SAPL/SIPP, sliplining) to choose the optimum method per segment; see Pipe Rehabilitation.
Advanced inspection (vactor cleaning, robotic CCTV, condition coding) and documentation to support design and QA/QC; see Inspection.
Rapid emergency response with 24/7 availability and dedicated storm/flood services, including bypass and temporary pumping; see Emergency storm & flood response.
Regional manufacturing/wetout positioning to accelerate schedule, including a secondary wetout facility in Morganton, NC noted on CIPP North Carolina.
Integrated electrical and bypass teams for complex lift stations and crossings; see Repair & Replacement.
Safety‑first operations supported by an OSHA‑certified safety program and low EMR; see About.

Scoping checklist for 36–120 in culvert rehabilitation

CCTV and cleaning reports with defect codes, pipe shape, and material (CMP, RCP, HDPE, PVC, elliptical/box geometry notes).
Host dimensions (ID/OD), wall condition, ovality, and geotechnical considerations (cover, groundwater, tidal influence, traffic loads).
Hydraulics: pre‑cleaning vs. post‑cleaning capacity, surcharge/tidal conditions, critical crossings, and downstream control points.
Access constraints (work windows under roadways/rail, environmental/tidal windows, detour feasibility), bypass and dewatering requirements.
Desired outcomes: full structural renewal vs. corrosion barrier, flow improvement targets, lifespan objectives, and restoration standards.

Next steps

Engage the inspection/condition assessment team to finalize method selection and staging: Inspection.
For design‑assist or emergency mobilization, contact the team: Contact Us.
Explore the trenchless options Hinterland performs in‑house: Pipe Rehabilitation.

Large‑Diameter Stormwater & Culvert Rehabilitation (36–120 in)