EPANET Water Distribution Networks (.inp)

@modelscript/epanet (languages/epanet) provides native parsing, hydraulic simulation, DAE lowering, and formal verification for US EPA EPANET pressurized drinking water distribution networks and municipal water infrastructure.

---

Supported Extensions & Standards

Extension	Format	Description
.inp	EPANET Input File	Industry-standard network topology, pipes, pumps, valves, and water quality decks

---

Key Capabilities

1. Todini Global Gradient Method (GGM) Hydraulic Solver

• Implements the Todini Global Gradient Algorithm (todini-ggm.ts) for quadratic/nonlinear pipe network equilibrium:
  • Conservation of Mass at Junctions:$$\sum _{k\in \text{in}(i)}{Q}_k-\sum _{k\in \text{out}(i)}{Q}_k=D_i$$
  • Conservation of Energy across Pipe Loops:$$h_i-h_j=h_{L,ij}=r{Q}_{ij}|Q_{ij}{|}^{\alpha -1}$$
• Supports Hazen-Williams, Darcy-Weisbach, and Chezy-Manning head loss friction models.

2. Multi-Component Hydraulic Elements

• Pumps: Head gain curves modeled via 3-point polynomial and power-law relationships ($h_p=h_0-a{Q}^b$).
• Tanks & Reservoirs: Dynamic elevated storage tanks with hydrostatic pressure differential equations:$$A_{\text{tank}}\frac{dh}{dt}=\sum Q_{\text{in}}-\sum Q_{\text{out}}$$
• Control Valves: Pressure Reducing Valves (PRV), Pressure Sustaining Valves (PSV), and Flow Control Valves (FCV).

3. Direct DAE Lowering & Modelica Projection

• Compiles the entire municipal pipe and tank network into @modelscript/runtime's DAEBuilder SoA linear memory arena.
• Projects EPANET networks into standard Modelica.Fluid pipes, reservoirs, and centrifugal pumps for joint thermo-fluid studies.

---

Static Analysis & Pre-Flight Linter Rules

8 rules7 error1 warning Run with msx epanet lint

Code	Rule	Severity	Message
M8101	isolated-hydraulic-node	error	Hydraulic node '<nodeId>' is isolated with no connecting pipes or pumps.
M8102	negative-pressure-risk	warning	Junction '<nodeId>' elevation (<value>m) exceeds maximum network source head (<value>m), risking cavitation and dry-out.
M8103	non-monotonic-pump-curve	error	Pump head curve '<curveId>' violates decreasing monotonicity: head increases from <value> to <value> between flow <value> and <value>.
M8104	zero-length-pipe	error	Pipe link '<pipeId>' has non-positive physical length (<value>m).
M8105	zero-diameter-pipe	error	Pipe link '<pipeId>' has non-positive internal diameter (<value>mm).
M8106	duplicate-node-id	error	Duplicate node identifier '<nodeId>' detected in water network topology.
M8107	duplicate-link-id	error	Duplicate link identifier '<linkId>' detected in water network topology.
M8108	unreferenced-node-in-link	error	Link '<linkId>' references undefined endpoint node '<nodeId>'.

Generated from languages/epanet/src/lints/rules.ts. All languages →

---

CLI Usage

# Lint an EPANET municipal water network
msx epanet lint MunicipalWaterNetwork.inp

# Solve steady-state network hydraulics (Todini GGM) and print pressures
msx epanet solve MunicipalWaterNetwork.inp

# Lower network dynamics into ModelScript linear DAE arena
msx epanet to-dae MunicipalWaterNetwork.inp --out=network.dae.json

# Project into standard Modelica.Fluid components
msx epanet to-modelica MunicipalWaterNetwork.inp -o MunicipalPipes.mo