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normal (uniform-flow) depth for a given discharge in rectangular, trapezoidal, triangular, or circular channels using bisection method","exampleAgentPrompt":"What is the normal depth for a rectangular concrete channel (Manning n = 0.013) with a bottom width of 3 metres, a bed slope of 0.001, and a discharge of 5 m³/s using SI units?","exampleUseCases":[{"title":"Irrigation canal design check","prompt":"I'm designing a trapezoidal irrigation canal with a bottom width of 2 m, side slopes of 1.5, Manning n of 0.025, bed slope of 0.0005, and a design discharge of 3 m³/s — what normal depth should I design for in SI units?"},{"title":"Concrete stormwater pipe sizing","prompt":"For a circular concrete storm pipe with a diameter of 1.2 metres, Manning n of 0.013, slope of 0.002, and peak flow of 1.8 m³/s, what is the normal depth of flow in SI units?"},{"title":"Natural channel flood depth estimation","prompt":"I have a natural trapezoidal channel with bottom width 5 ft, side slopes of 2, Manning roughness 0.035, slope 0.004, and a flood discharge of 120 ft³/s — what is the normal depth in US customary units?"}],"resultDescription":"Returns the computed normal depth (metres or feet), along with derived hydraulic properties including flow area, top width, average velocity, Froude number, flow regime classification (subcritical/supercritical/critical), channel shape, and unit system used. May also include a summary, disclaimer, and degraded-result flag if the solver had convergence issues.","failureModes":["No solution found if discharge is too large for the given geometry (e.g., flow exceeds pipe capacity) — returns error or null normalDepth","Invalid or missing required parameters (shape, flow, n, slope) return a validation error","Unsupported shape string returns an error — only 'rectangular', 'trapezoidal', 'triangular', 'circular' are accepted","Missing geometry for shape (e.g., no bottomWidth for rectangular) causes a parameter error","Zero or negative slope or flow values may cause bisection failure or undefined result","Very flat slopes or extreme roughness values may cause slow or non-convergent bisection"],"whenToPreferThis":"Choose this endpoint when you need to solve for the unknown normal (uniform-flow) depth given a known discharge, channel geometry, roughness, and slope — specifically using bisection on Manning's equation. It is the right choice for open-channel hydraulic design tasks where depth is the unknown. Use it over Manning flow endpoints (which give Q given depth) when depth is what you need to find. Ideal for engineers designing canals, storm sewers, culverts, and natural channel assessments.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-02T18:32:44.652Z","isFirstParty":false,"canonicalSlug":"hydrology-open-channel-calc-normal-depth-a3b1e376"}