Catch Basin and Yard Drain Cost
Key points
Price the inlet and the receiving system together
A catch basin collects water; it does not by itself establish where water should go. The proposal should identify basin size and grate, inlet elevation, pipe size and route, cleanout access, outlet, bedding or trench work, and surface restoration. Ask whether the basin is intended for a roof discharge, a low lawn, a patio edge, or concentrated runoff from a slope.
The basin location should be based on actual grade and maintenance access, not only on the most visible puddle. Multiple inlets, an upslope diversion, or a channel may be needed if the source is broad. Conversely, a basin can be the wrong scope if regrading can safely remove the low point or if the outlet cannot accept the flow.
Before approval, ask how leaves and sediment will be removed, whether the grate suits the traffic around it, and how the system will be tested in a storm. Separate excavation, pipe, outlet, disposal, restoration, and local review from the visible basin price. Utility locating and discharge requirements need local confirmation.
- A basin collects water; the pipe and outlet complete the system.
- Multiple inlets and long buried runs increase excavation and restoration exposure.
- Use a scope breakdown instead of a generic “yard drain” price.
- Keep roof-water routes separate from foundation drains unless a qualified design says otherwise.
Size the collection network around the contributing area
The number of basins should follow the water path, not a standard count per yard. One inlet may be enough for a small, clearly defined depression. Several inlets may be needed where runoff crosses a broad paved edge, arrives from a slope, or follows more than one route. In other cases, a basin adds cost without solving the cause because a grade correction would have kept water from concentrating there in the first place.
Ask how the contractor selected inlet locations and elevations. The grate must sit where water can reach it without creating an unintended trip or access problem, and the basin should remain serviceable after soil, mulch, snow, or planting is restored. A low inlet can collect sediment quickly; a basin placed in a high-flow path may need a different cover or surrounding stabilization.
Compare collection with other interventions
A catch basin is most useful when water is already concentrated and a buried route is practical. A channel drain may better intercept a line of runoff at a patio, walkway, or garage approach. A swale may move water visibly across an open yard, while regrading may remove the low point. A French drain addresses different subsurface or interception conditions. Compare these choices by the water source, available grade, outlet, maintenance, and restoration rather than by the inlet price alone.
Compare proposals by the complete route
Ask every bidder to identify the inlet locations and elevations, pipe route and assumptions, discharge point, excavation and access method, utility allowance, spoils or disposal, surface restoration, cleanouts, testing, and maintenance access. The proposal should also say what is excluded: outlet or connection work, difficult digging, private utilities, imported material, restoration beyond the trench, taxes, or changes caused by an unavailable discharge point.
Two bids are not comparable when one prices only a basin and short pipe while the other includes a route to a workable outlet. Request the same marked-up route and receiving point for each alternative, and ask how the price changes if the contributing source is broader, the route crosses existing hardscape, or the assumed discharge is not available. A clear exclusions list is part of the drainage cost, not paperwork after the price is chosen.
Include the receiving system in maintenance planning
The pipe and outlet need attention too. Ask how leaves and sediment will be removed from each basin, whether cleanouts can be opened, and how the outlet will be checked after a large storm. If discharge enters an infiltration feature, public system, street, swale, or neighbouring area, verify the local requirements and overflow route. Keep a route sketch and photographs before cover so a later service visit does not become exploratory excavation.