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New Hampshire's precast concrete drainage work on state projects is governed by the New Hampshire Department of Transportation (NHDOT). The requirements for drainage structures, reinforced concrete pipe, box culverts, and the concrete itself live in the Standard Specifications for Road and Bridge Construction, with details carried on the state's standard drawings. Precast producers read those documents alongside the project plan set to know what to make and how it will be accepted.
NHDOT conveys drainage design on the plans as numbered freetext Drainage Notes rather than a tabular summary. The grammar and sequence for writing these notes are published in the NHDOT Highway Design Manual, Chapter 13, Appendix 13-12, titled Drainage Note Format. Chapter 6 of the same manual carries the broader drainage design guidance.
Standard Specifications for Road and Bridge Construction, 2026 (effective for projects advertised after July 1, 2026; prior edition 2016). The sections below cover precast drainage structures, pipe, culverts, and concrete.
| Section | Title |
|---|---|
| 520 | Portland Cement Concrete |
| 544 | Reinforcement for Concrete |
| 603 | Culverts and Storm Drains |
| 604 | Catch Basins, Drop Inlets, and Manholes |
Section numbers are a reference. Confirm them against the current specification and any special provisions for your project.
NHDOT publishes a Standard Plans Snapshot (current snapshot dated August 1, 2026) plus individual detail sheets. Drainage sheets use the DP and DR prefixes, including DP-1 Drainage Pipe Details and DR-5 Precast Reinforced Concrete Catch Basin, Drop Inlet, and Manhole.
The Product Qualification Criteria page organizes qualified products by specification section. Under Section 604 it lists Fiber Reinforcement for Precast Drainage Structures, with concrete-related entries under Sections 520 and 544. The page does not list a separate approved-precast-fabricator roster.
NHDOT conveys drainage design on the plans as numbered freetext Drainage Notes rather than a tabular summary. The grammar and sequence for writing these notes are published in the NHDOT Highway Design Manual, Chapter 13, Appendix 13-12, titled Drainage Note Format. Chapter 6 of the same manual carries the broader drainage design guidance.
DhyanaERP reads NHDOT drainage summaries today.
DhyanaERP Drainage Summary Import reads a plan set, finds the drainage structure sheets, transcribes them under a strict extraction contract, checks the engineering, and turns each row a person confirms into a priced structure. This status describes DhyanaERP's reading capability only. It is not a statement of DOT approval.
See DhyanaERP Precast EditionSection 603 (Culverts and Storm Drains) covers culvert and storm drain pipe, including reinforced concrete pipe, and Section 604 (Catch Basins, Drop Inlets, and Manholes) covers those precast structures. Concrete and reinforcement requirements fall under Section 520 (Portland Cement Concrete) and Section 544 (Reinforcement for Concrete).
The 2026 edition, effective for projects advertised after July 1, 2026. The 2016 edition remains posted as the prior reference.
NHDOT presents drainage information as numbered Drainage Notes on the plans. The format for those notes is published in the Highway Design Manual, Chapter 13, Appendix 13-12, Drainage Note Format, with design guidance in Chapter 6.
No separately numbered sections carry those exact titles. These precast items are handled through the general concrete and reinforcement sections, structural standard plan details, and project special provisions, with culvert and storm drain work under Section 603.
Every link points to the agency's own site.
DhyanaTech is not affiliated with or endorsed by any state DOT.
Reference only. Not engineering or legal advice. Always confirm against the current specifications and the contract documents for your project.
Last verified November 2026.