Comparison

HydroSewer vs Culvert Studio

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

HydroSewer

Features
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HydroSewer is a professional stormwater and sewer network analysis tool powered by the EPA SWMM 5 engine. Build, analyze, and simulate drainage networks from your phone or tablet. KEY FEATURES - Import standard EPA SWMM input files (.inp) and simulate them with the EPA SWMM 5 engine on your device, with no account and no cloud - Junctions, outfalls, storage, conduits, pumps, weirs, orifices, and subcatchments on an interactive canvas - Step through results over time: depth at nodes, flow and velocity in conduits, and more - Edit node, link, and subcatchment properties; renaming or deleting an element updates the data that refers to it, and broken references in older projects can be repaired - Give a node its sewage flow (DWF), with an optional hourly pattern, and a direct inflow; before a run, the app flags flat pipes, unset manholes, or no inflow at all - New network, Save, and Save as in the menu; Demo Village, a sample network, to try it all MAP BACKGROUND (OPTIONAL) - Your network over Google Maps, map or satellite, with adjustable visibility - Find your area on the map: tap your town and HydroSewer proposes the coordinate system that fits, if it knows one - Or set UTM, or a Transverse Mercator grid in Advanced - A .inp that declares a supported EPSG code (Q_VAR_PROJECTION) lands in place with no setup - Local coordinates? Line the network up by tapping a node and its place on the map, a few times - You turn the map on. It needs a connection; without one, the network is shown without it LAY OUT A NETWORK IN THE FIELD Start a new network and tap Use my location: the map centers where you are and a dot shows your position as you walk. Add each manhole by tapping its place on the map; your location never places or moves one. A preliminary layout, not a survey. FIELD NOTES - Attach notes and photos to any manhole, outfall, or pipe: as-built discrepancies, observations, a "check this" for the office - Open or resolved; elements with open notes are highlighted, and one list gathers every open note - With location allowed, a note records where it was taken and how accurately, with Show on map - Saved in your project, never in the .inp file CORE FEATURES WITHOUT INTERNET Modeling, simulation, saving, and field notes work with no connection, wherever the signal doesn't reach. Apart from the store's purchase service, only the optional map background uses the internet, through Google Maps. PRIVACY Transparent Blue Water does not receive your data. When you turn on the optional map background, Google Maps receives the map area you view. Your GPS reading, if you allow it, is used on your device and never sent anywhere; a note's position stays in your project and its PDF until you share them. FREE, WITH NO SIZE CAP No cap on network size, field notes, or photos; the map background is free too. HydroSewer Pro is an optional one-time purchase that adds: - Export the network as a standard SWMM .inp file - Export node and link results to CSV, every time step - A PDF report of your field notes with your logo, model data per element, the photos, and map links to where notes were taken - Save a network's alignment on the map IMPORTANT HydroSewer is an independent engineering tool. Results are computed by the EPA SWMM 5 engine and must be reviewed and verified by a qualified, responsible engineer before any design, construction, permitting, or other professional use. HydroSewer does not certify or guarantee compliance with any code, standard, or regulation, and is provided "AS IS" without warranty of any kind. HydroSewer is not affiliated with, endorsed by, or sponsored by the U.S. Environmental Protection Agency (EPA). References to EPA and SWMM are used solely to identify the simulation engine. Map data and imagery: Google Maps.

About

Culvert Studio

Features
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Culvert Studio is a free, educational showcase of our engineering-software capabilities β€” built to demonstrate the kind of tools we can create for professionals in civil engineering, drainage, stormwater, and hydrology. WHAT YOU CAN EXPLORE - Rational Method + Manning's equation for peak-flow and culvert sizing - Recommended culvert size, design flow, and velocity β€” in seconds - Inlet/outlet control analysis with performance curves and headwater checks - Multi-barrel, orifice, weir, and tidal-tailwater analysis for coastal culverts OFFLINE CANADIAN IDF DATA - 565 IDF weather stations across all 13 provinces and territories - 28,900+ data points β€” rainfall intensity/duration/frequency curves, fully offline - No internet required at the job site VISUALIZE & VERIFY - Interactive 2D/3D culvert profile with design-flow animation - Velocity, HW/D, and compliance checks against provincial drainage manuals (ON, AB, BC, SK, MB, QC) - Save projects and calculations; export reports as PDF or GeoJSON/KML MORE THAN A CALCULATOR - Bridge hydraulics, fish passage, detention, channel, and drainage-network tools - Environmental data integration: tidal (CHS IWLS), snow (ECCC), hydrometric (WSC) - Bilingual English / FranΓ§ais AN EDUCATIONAL DEMONSTRATION Culvert Studio is provided as an educational, experimental showcase of what we can build β€” not as a substitute for professional design software. Always have results verified by a qualified engineer. Built for Canadian conditions. Works offline. If you work in civil engineering, drainage, stormwater, or hydrology, we'd love to hear from you. Request a feature, suggest an improvement, or contact us about a custom solution.

Screenshots

HydroSewer4 screens
Culvert Studio4 screens

Verdict

The call

The clearest difference is in-app purchases: Culvert Studio at none against HydroSewer's 1. Culvert Studio also leads on update cadence (daily vs every 3 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. HydroSewer sells 1 one-off in-app purchase. Culvert Studio asks for nothing beyond the download.

UpkeepUpdate frequency

HydroSewer ships an update every 3 weeks, Culvert Studio daily. The most recent releases landed on October 28, 2026 and October 18, 2026 respectively.

Scorecard2 real differences Β· 4 level
HydroSewer versus Culvert Studio: the parameters behind the verdict, then further details
ParameterHydroSewerCulvert Studio
PriceFreeFree
Update frequencyEvery 3 weeksDaily β€” better
AdsNoNo
In-app purchasesYesNo β€” better
DevicesiPhone, iPad, iPod β€” betteriPhone, iPad
Requires iOS15.0 β€” better16.0
Further details β€” not scored
Size51 MB43 MB
Age rating+44+
DeveloperTransparent Blue Water LLCJagdeep Singh

In-app purchases

1 purchases

HydroSewer

One-time1
  • HydroSewer Pro$14.99
None

Culvert Studio

No in-app purchases

Questions

Is HydroSewer free?
HydroSewer is free to download, with in-app purchases available.
Is Culvert Studio free?
Culvert Studio is free to download, with no in-app purchases.
Do HydroSewer or Culvert Studio have ads?
Neither HydroSewer nor Culvert Studio shows ads.
Which is updated more often, HydroSewer or Culvert Studio?
HydroSewer ships an update every 3 weeks, and Culvert Studio daily. Most recently, HydroSewer was updated on October 28, 2026 and Culvert Studio on October 18, 2026.

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