Water distribution
Pressurized networks
The Water skill turns Nexma into a pressurized water-distribution platform. It models the network from treatment plant to customer meter, validates pressure across the whole graph, and sizes pumps against elevation. Where a fiber project worries about optical loss, a water project worries about head — and this ontology makes that the organizing rule.
What this skill models
The ontology captures a hydraulic network with the entity types, link types, and constraints a distribution engineer expects.
- Entity types.
TreatmentPlant,PumpStation,StorageTank,Valve,Hydrant,Meter,PressureSensor, andPressureZone. Each carries typed properties — flow rate, static head, valve class, meter size. - Link types.
TransmissionMain,DistributionMain, andServicePipe. Every pipe carries diameter, material, roughness coefficient, and design pressure. - Key constraints. A minimum of 40 PSI at meters and a maximum of 60 PSI in distribution mains; flow conservation at every junction; and valve-isolation segments that must remain reachable for maintenance.
The ontology ships the reference data a designer would otherwise table-lookup: AWWA pipe-class tables, Hazen-Williams roughness coefficients by material, standard hydrant flow ratings, and pressure-zone elevation bands.
What Jax can do
Jax reasons hydraulically because the Skill binds its capabilities to this ontology.
- Generate distribution layouts. "Lay mains to every parcel in this polygon. Hold pressure at or above 45 PSI everywhere. Use 8-inch DI on collectors, 6-inch on locals." Jax routes mains along the street network and sizes pipe to hold the budget.
- Size pumps from the elevation difference, including head loss for fittings.
- Validate pressure across long branches and across pressure-zone boundaries, flagging any over-budget path inline.
- Place hydrants on a coverage grid with spacing rules that vary by land-use class.
- Plan valves so isolation segments stay small enough to repair without a major service interruption.
Pressure simulation runs through the Nexma MathEngine and writes results back to the world model, so meters show their simulated pressure under design demand the instant the run finishes.
Tip: Set the controlling tank or pump head before generating mains. Static head sets the ceiling for every downstream node, so fixing the source first keeps the pressure solve from chasing a moving target.
Constraints and standards
The skill enforces the rules a distribution design must satisfy to be approvable.
| Concern | Rule enforced | Standard |
|---|---|---|
| Service pressure | 40 PSI minimum at meters | Ten States Standards |
| Main pressure | 60 PSI maximum in distribution | Ten States Standards |
| Pipe sizing | Class by pressure and material | AWWA / ANSI-AWWA C150 |
| Friction loss | Hazen-Williams by material | AWWA reference tables |
| Isolation | Every segment valve-reachable | Distribution design practice |
Export targets include GeoJSON, EPANET INP, and shapefile from Project to Export.
Out of scope today: wastewater and stormwater (a separate skill, planned), real-time SCADA writebacks (read-only operational dashboards only), and detailed cathodic-protection design.
Where to go next
- Electric distribution — the same generate-validate pattern for power.
- Skills overview — the full catalog.
- The ontology — how constraints like the pressure budget are defined.
- Nexma MathEngine — the simulation layer behind the pressure solve.