Build reproducible watershed modeling pipelines in Python.
Practical, production-grade guides for hydrologists, environmental engineers, and Python GIS teams. Condition DEMs through roads and culverts, route flow with D8 / D∞ / MFD, vectorize and order stream networks, delineate watersheds at continental scale, build design storms, and fit flood-frequency curves — all from one consistent automation playbook.
What you will find here
Watershed Modeling is a focused reference for automating hydrologic workflows in Python. Every page is built around concrete, reproducible patterns: which library to reach for, why a routing algorithm behaves the way it does on a given terrain, and how to wrap it in a defensible pipeline with logging, idempotency, and topology validation.
Whether you are moving from desktop GIS to a code-driven pipeline, integrating LiDAR into an operational workflow, or scaling watershed delineation across a continent of tiles, the content here favours the algorithmic depth and engineering rigour that production agency-grade work demands — not surface-level tutorials.
The collection now runs to 84 pages across four sections and 22 topic areas, every one of them carrying runnable Python, a validation protocol that can fail, and hand-authored diagrams of the mechanism being described. Recent additions cover hydro-conditioning through road embankments, stream-network vectorization and ordering, tiled processing for datasets larger than memory, design-storm construction, and flood-frequency and low-flow statistics from gauge records.
Start here
New to automated watershed modeling? These guides establish the foundation — from acquiring your first DEM to producing a validated stream network and simulating the runoff hydrograph it drains.
- How to Download SRTM DEMs for Python Hydrology Workflows
- Best Practices for Filling Sinks in High-Resolution LiDAR Data
- Implementing D8 Flow Routing with RichDEM Python Bindings
- Tuning Flow Accumulation Thresholds for Ephemeral Streams
- Partitioning Large Watersheds into Sub-Basins with RichDEM
- SCS Curve Number Runoff Estimation
- Hydro-Conditioning for Culverts and Road Crossings
- Stream Network Vectorization and Ordering
- Precipitation Forcing and Design Storms
Browse the sections
Four sections cover the full hydrologic pipeline from raw elevation data through hydrologically sound catchments to simulated runoff hydrographs and the gauge statistics that check them. Each section drills into specific implementation guides with code, validation strategies, and the operational pitfalls that only surface in production.
Hydrology Data Preparation & DEM Processing
Acquire, harmonize, and condition DEMs into hydrologically sound surfaces — CRS alignment, pit filling and breaching, culvert and road-crossing conditioning, resolution tradeoffs, and SRTM/LiDAR acquisition.
Explore sectionFlow Routing & Stream Network Extraction
Implement D8, MFD, and D-infinity routing, tune flow accumulation thresholds, and turn the result into a connected, ordered stream network with RichDEM, WhiteboxTools and pysheds.
Explore sectionWatershed Delineation & Catchment Synchronization
Map outlets, partition basins, validate boundary topology, and synchronize nested catchments — including tiled and parallel processing for datasets larger than memory.
Explore sectionRainfall-Runoff Modeling & Hydrologic Simulation
Drive HEC-HMS and SWMM from Python, build design storms and unit hydrographs, calibrate against gauged flow, and fit flood-frequency and low-flow statistics from the gauge record.
Explore sectionAll topics
All 84 pages, organised by section and topic. Jump directly to the technique or pipeline stage you need — conditioning, routing, delineation, forcing, calibration or statistics.
Hydrology Data Preparation & DEM Processing
Flow Routing & Stream Network Extraction
Watershed Delineation & Catchment Synchronization
- Basin Partitioning Strategies for Automated Watershed Modeling
- Boundary Topology Validation for Automated Catchment Delineation
- Nested Catchment Delineation: Automated Python Workflows
- Outlet Point Mapping & Validation
- Pipeline Orchestration: DEM to Watershed Automation
- Tiled and Parallel Watershed Processing