How to read drawings

Sewer pipelines (drainage facilities) inside residential areas and private roads cannot be viewed because there is no material for personal property. Please check with the owner or user of the land or carry out a field survey.

Types and functions of sewer pipelines

Combined sewer systems	(Solid line) Combined sewer: Sewer in which both sanitary sewage (including miscellaneous wastewater) and stormwater both flow
Separate sewer system	(Dotted line) Sanitary sewer: Sewer in which only sanitary sewage (including miscellaneous wastewater) flows	(Broken line) Stormwater sewer: Sewer in which only stormwater flows In separate sewer system areas, house inlets and stormwater inlets for residential drainage are necessary.

How to view the facility plan

In the facility plan, the upward direction shows North.
The arrow (←) on the sewer pipeline indicates the direction of sewage flow.
Information on sewer pipelines is stated between manholes.
Information on sewer pipelines may be displayed near the sewer pipeline or on the leader line.
The height of the ground and the pipe bottom is an elevation, being the height from the average sea level of Tokyo Bay (T.P.).

Embedment status of sewer pipeline

The height of the ground and the pipe bottom is an elevation, being the height from the average sea level of Tokyo Bay (T.P.).
Covering is the depth from the ground surface to the upper edge of the sewer pipeline.
House connection is a pipe that connects the inlet and the sewer pipeline.
(Normally, the house connection for house inlets has an inner diameter of 15 cm, and the house connection for stormwater inlets has a diameter 20 cm.)

Types of sewer pipelines

Symbol		Meaning of symbol
		Combined branch line
		Sanitary sewage branch line
		Stormwater branch line, LU pipe, LP pipe, stormwater discharge pipe
		Combined trunk line
		Sanitary sewage trunk line
		Stormwater trunk line, rainwater discharge trunk line, effluent conduit
		Combined force main branch line
		Sanitary sewage force main branch line
		Stormwater force main branch line
		Combined force main trunk line
		Sanitary sewage force main trunk line
		Sludge transportation pipe
		Reclaimed wastewater recycling system (central waterworks)
		Air pipe
		Unknown / others
		Provisional intake pipe

Sewer pipeline cross-sectional shape

Symbol		Meaning of symbol
		Circular
		Rectangular
		Horseshoe-shaped
		Back split (circular)
		Egg shape
		LU shape
		LP shape
		Back split (rectangular)
		Multiple section
		Slipling
		Trapezoid
		Circular multiple (rectangular)
		Circular multiple (circular)
		Rectangular multiple (rectangular)
		Rectangular multiple (circular)
		Other cross-sections (rectangular)
		Other cross-sections (circular)
		Other cross-sections (rectangular / circular)
		Other cross-sections (special)
		Dual pipes
		Construction of circular pipe invert

Types of manholes

Symbol		Meaning of symbol
		Rectangular manhole (inner dimensions 90 cm × 60 cm)
		Circular manhole (inner diameter 90 cm)
		Oval shape manhole (inner diameter 120 cm × 90 cm)
		Circular manhole (inner diameter 120 cm)
		Circular manhole (inner diameter 150 cm)
		Circular manhole (inner diameter 180 cm)
		Circular manhole (inner diameter 200 cm)
		Circular manhole (inner diameter 220 cm)
		Tokyo-original assembled rectangular manhole (inner dimensions 90 cm × 60 cm)
		Tokyo-original assembled rectangular manhole (inner dimensions 120 cm × 60 cm)
		Tokyo-original assembled rectangular manhole (inner dimensions 120 cm × 80 cm)
		Tokyo-original assembled rectangular manhole (inner dimensions 120 cm × 90 cm)
		Assembled circular manhole (inner diameter 90 cm)
		Assembled circular manhole (inner diameter 120 cm)
		Assembled circular manhole (inner diameter 150 cm)
		Assembled circular manhole (inner diameter 180 cm)
		Assembled circular manhole (inner diameter 200 cm)
		Assembled circular manhole (inner diameter 220 cm)

Symbol		Meaning of symbol
		Special manhole (assembled manhole)
		Special manhole (inner diameter less than 90 cm)
		Special manhole (inner diameter 90 cm or more)
		Special manhole (with automatic sludge elutriation tank)
		Diversion manhole
		Manhole with tidal gate
		Siphon manhole - Upstream
		Siphon manhole - Intermediate
		Siphon manhole - Downstream
		Siphon diversion manhole - Upstream
		Siphon diversion manhole - Downstream
		Siphon manhole with tidal gate - Upstream
		Siphon manhole with tidal gate - Downstream
		inspection manhole
		Double use manhole
		Lamp hole
		Provisional intake
		Manhole with unknown shape
		Flow direction adjustment part

Type of public inlet

Symbol		Meaning of symbol
		House inlet
		Stormwater inlet (including for stormwater drainage, special stormwater inlet)
		Special house inlet
		Stormwater inlet (two lids) (for stormwater drainage)
		Stormwater infiltration inlet (single stormwater control inlet) (for stormwater drainage)
		Stormwater infiltration inlet (double stormwater control inlet) (for stormwater drainage)
		Stormwater infiltration inlet (triple stormwater control inlet) (for stormwater drainage)
		Small house inlet
		LU / LP stormwater drainage inlet
		Stormwater inlet for residential drainage
		Small stormwater inlet for residential drainage
		LU final special stormwater inlet (Setagaya, Ota Cities)
		Stormwater inlet for residential drainage relay street inlet (Keihinjima area)
		Stormwater infiltration inlet for residential drainage
		Stormwater infiltration inlet (for stormwater drainage) and infiltration connecting pipe
		Special inlet
		House connection (same color as the inlet.)

Type of change point or junction point

Symbol		Meaning of symbol
		Intake port, discharge port, external pipe intake part, etc.
		Wastewater treatment plant, inlet or outlet to pumping station
		Underground junction point, tubular change part, etc.
		Upstream part of private road intake pipe or road manager classification point
		Air valve
		Sluice valve
		Blowoff
		Inspection port (including cleaning port)

Symbols representing terrain, administrative boundaries, etc.

Symbol		Meaning of symbol
		Public road
		Private road
		River
		Railway (JR)
		Railway (private)
		Retaining wall (slope, etc.)
		Prefectural boundary
		City boundary
		District boundary / block boundary

Other symbols

Symbol		Meaning of symbol
		Distribution (origin of left and right pipes)
		Double use origin (origin of right pipe)
		Secondary pipe (place where the difference in elevation between the upstream pipe and the manhole bottom is large, etc.)
		Slipling (additional pipe on the outside of a pipe: measure to protect the pipe)
		Transfer symbol (actual pipes overlap: congestion area)