Drainage bids carry a long list of per-LF pipe runs and per-EA structures — and that's exactly why work gets left out and the unit prices get gamed. Bid Reasoner normalizes every drainage and storm-sewer sub bid to your scope of work, scores it across six dimensions, and runs four deterministic risk rules over the pipe and structure prices before you award. It's the trade-level version of our subcontractor bid analysis.
Five to nine drainage subs bid a storm-sewer package. One total comes in 18% under the field. On a spreadsheet that bidder looks like the obvious pick — until you read the line items and find no trench dewatering, pavement restoration assumed into the GC's scope, and connections to the existing system priced at a penny each. The number is low because the work is missing, not because the bidder is sharp.
Drainage spreads its cost across many lines — pipe by size and material, structures by the each, excavation and backfill — so a few dollars per LF, a front-loaded mobilization, or one omitted item moves the award. By eye, across bids in different formats, you catch some of it. The ones you miss become the change order on the dewatering you thought was included, or the dispute over the restoration that failed.
Before you compare totals, confirm every bidder priced the same work. These are the items a complete drainage and storm-sewer bid should carry, and the dimension each maps to.
| Line item | Why it matters | Dimension / flag |
|---|---|---|
| Pipe by size / material (RCP, HDPE) per LF | The largest spread of lines; RCP and HDPE price very differently per linear foot. | Price · peer outlier >2× / <0.5× |
| Catch basins / inlets / manholes (EA) | Priced per each; depth and frame-and-grate type drive the unit price. | Price · unbalanced ≤ $1.00 |
| Trench excavation & backfill | Quantity-heavy line tied to pipe depth; varies widely by assumed conditions. | Price · scope |
| Bedding stone | Sometimes folded into excavation; confirm it's priced as its own line. | Scope · gap analysis |
| Headwalls & end sections | Spec-required terminations; map to state-DOT items and easy to overlook. | Scope · compliance |
| Connections to existing | Tie-ins to live systems are real work, routinely penny-priced or omitted. | Scope · gap analysis |
| Trench dewatering | Pushed to the GC more than any other line; price it explicitly. | Scope · gap analysis |
| Pavement restoration | Often assumed away; a missing restoration line isn't a saving, it's short scope. | Scope · gap analysis |
| Testing / CCTV | Required acceptance step frequently pushed off the bid; confirm who carries it. | Compliance · gap analysis |
These are the lines that quietly drop out and make a total look low. Bid Reasoner's two-way scope-coverage gap analysis surfaces each one against your scope of work.
Pushed to the GC more often than any other line. If it isn't priced, that cost lands on you after award.
Routinely assumed away when the trench crosses a road. Its absence is a scope gap, not a price advantage.
Tie-ins to live systems are real work and often penny-priced or dropped. A bidder that skipped them isn't cheaper, it's short scope.
Acceptance testing and CCTV inspection are a real cost that's easy to push off the bid. A missing line is a compliance and scope risk.
Every drainage bid runs through the same four deterministic rules, with fixed numeric thresholds. These are the patterns they catch in drainage specifically.
Per-LF pipe prices and per-EA structure prices are where bids get unbalanced; penny-priced catch basins and manholes are the tell. Flagged when a unit price falls at or below $1.00.
RCP and HDPE runs carry much of the cost, so a $/LF priced far off the field — high to chase quantity overruns, low to win — moves the award. Flagged above 2× or below 0.5× the peer median.
Mobilization above 10% of the total is the classic front-load, and a total more than 20% off the field is flagged — paired with the scope gap, it shows whether the bidder is sharp or simply left dewatering and restoration out.
Upload or forward every drainage and storm-sewer sub bid for the package. Bid Reasoner reads each PDF, extracts the line items, and normalizes them to your scope of work so the pipe runs by size and material, the structures, excavation, and testing line up item for item — even when each bidder's form looks nothing alike. Every bidder is then scored across price, scope, schedule, compliance, performance, and risk, and the four deterministic rules run over the numbers.
The scope-coverage gap analysis surfaces the dewatering, pavement restoration, connections, or CCTV testing a bidder didn't quote — the difference between a sharp number and a short one. Every score links to a page-cited quote from the source bid, so the answer to "why this sub?" is on the record. Recommend a winner under any of 7 decision modes — from Lowest Responsible Bid to Best Value — with a confidence score, and carry the reasoning, the risk flags, and any forced override straight into the award memo with a full audit trail.
A complete drainage and storm-sewer bid prices pipe by size and material — RCP and HDPE — per linear foot, catch basins, inlets, and manholes each, trench excavation and backfill, bedding stone, headwalls and end sections, connections to existing systems, trench dewatering, pavement restoration, and testing or CCTV inspection. The per-LF pipe runs and per-EA structures carry the bulk of the price, so those unit prices are where the bid is won or lost. Bid Reasoner normalizes each bidder's line items to your scope of work so you can see, item for item, who priced what.
Trench dewatering, pavement restoration, connections to existing, and testing or CCTV inspection are the items most often missing from a drainage and storm-sewer bid. They are easy to assume into another line or push to the GC, and a frequent reason one bidder's total comes in low. Bid Reasoner runs a two-way scope-coverage gap analysis on each bidder — items in your scope the bidder didn't quote, and items the bidder priced that weren't in your scope — so the low number that's low because it left work out gets caught before award.
Bid Reasoner runs four deterministic risk rules over every drainage and storm-sewer bid. It flags unbalanced unit prices at or below $1.00 — the penny-priced catch basins and manholes — line items above 2x or below 0.5x the peer median, which is where the per-LF pipe and per-EA structure outliers show, totals that deviate more than 20% from the field, and mobilization above 10% of the total, the classic front-loaded bid. These are fixed numeric thresholds anyone can check, not a black-box score.
Built-in state-DOT pay-item baselines cover the civil drainage items — pipe by size and material, catch basins, inlets, manholes, and headwalls — and NY and NJ DOT baselines are built in as a head start. Outside those states, Bid Reasoner levels each drainage bid against the other bids in your package through peer-median normalization, so no government pay-item data is required to start. Bid Reasoner analyzes the bids you receive; it is not takeoff or quantity-estimating software.
Bring one package's drainage and storm-sewer sub bids. We'll normalize them to scope, score six dimensions, flag the pipe and structure risk, and recommend a winner on the call.