Storm Overflow Chamber (Engineered Unit)

A combined-sewer overflow chamber: a fixed pass-forward throttle to the works, a screened overflow weir whose crest is derived from the consented setting, a powered screen and a passive unscreened bypass.

Which simulation? Running this unit uses the client-side, PLC-style scan simulation in your browser, not the server-side biokinetic process simulation. See Which "simulation" this section is about.

Published. Seeded at published since 2026-10-24, so every Engineer in a tenant whose plan includes the engineering suite sees it in the stencil.

Slug	storm-overflow-chamber
Name in the library	Storm Overflow Chamber (Engineered Unit)
Category	Process Units/engineered
Seeded	version 0.1.0, maturity published
Interface points	5 — inlet, pass_forward, spill, signals, power
Asked on drop	7
Control loops	10 generated graphs

What it models

The first engineered unit whose only product is a record: the pass-forward is a fixed orifice and the spill is a weir crest, so the control system measures, rakes and reports (spill events and duration). The weir crests are derived: the screened crest at the chamber level that passes the consented setting, the unscreened bypass crest at the design spill with the screen at its design blinding. The pass_forward port publishes the continuation sewer's pipe-full capacity as the real ceiling, not just the setting.

Two rules to know

• The weir crest must sit below the incoming sewer's soffit. The crest is derived from the setting. If the setting you choose (or the rule set's DWF multiple) puts the crest at or above the incoming sewer's soffit, the chamber would back up the network before it spilled, so the unit refuses the configuration with a validation error. Lower the setting, or raise the incoming sewer (its invert or bore).
• A static screen raises a manual-clean alarm. A static screen has no powered rake. When the screen differential reaches the clean-start setting, the alarm schedule raises Static screen blinding: manual clean required (P2) so that an operator cleans it by hand. A powered screen rakes itself and does not carry this alarm.

Source

Template: packages/web/flow/templates/library/level-1/storm-overflow-chamber.ts; seed: ParametricTemplateSeeder (StormOverflowChamberId). Placing it works as described in Placing an Engineered Template. As with the other units, nobody has recorded watching it run in a browser.