Sewers of Waterdeep

Waterdeep's sewers run beneath the entire city, with the notable exceptions of the harbor islands and the heart of Mount Waterdeep, forming a subterranean "dungeon" between the surface and the depths of Undermountain. The uppermost portions of the sewers are in present use and fairly good repair, thanks to the efforts of the Cellarers' and Plumbers' Guild. Many older, smaller tunnels are walled up and not in use - at least, not to carry sewage.

The map shows only the largest passageways of the sewers. These are of two sorts - primary and secondary, according to size. Primary passages are 20 feet across and contain 3-foot-wide rail-less walkway ledges on both sides. Sewer workers cross passages by means of their 16-foot "catch-poles" to vault across or by the use of boards, which they lay down as temporary bridges. The catch-poles are also used for reaching below water level to clear debris from sewer gratings. Secondary passages are 12 feet across with a single 3-foot-wide ledge on one side (usually the more southerly or easterly). The countless feeder pipes (any sewer pipe less than 1 foot in diameter) and tertiary tubes (which can be crawled through by a Medium or smaller creature) are not shown.

Junction rooms are usually 30-foot-by-30-foot stone cubicles, 20 feet high with a sitting ledge near the ceiling, above the muck. Surface shafts are 6 feet in diameter with iron rungs set in the walls to use as ladders to and from the sewers. The entrance to a surface shaft is a 3-foot-wide hole capped by a removable metal (or metal-banded wood) cover.

The accompanying map is accurate, but some of its features (such as the junction rooms and surface-shafts) are distorted in size for clarity. The sewers themselves are unnamed, so those giving directions usually give them in relation to the point of entry.

Sewer Properties

Waterdeep's sewers have masonry ceilings, walls, and floors. The floors are considered to be light rubble, thanks to all the debris that has been deposited over the years, adding 2 to the DC of Balance and Tumble checks.

Air: The air supply is reasonably good (from a survival standpoint) in the sewers, as the numerous small feeder pipes bring stench-ridden air down from the surface in addition to refuse.

Ambient Noise: The echoing water flow produces lots of noise, providing a -4 circumstance penalty on all Listen checks in the network.

Disease: The sewers are filled with tainted water. Any activity that results in a character's nostrils, mouth, eyes, or ears getting wet requires a DC 16 Fortitude save to avoid contracting blinding sickness. Anyone injured by a slashing or piercing attack (including natural bite, claw, gore, and sting attacks) must make a DC 12 Fortitude save or contract filth fever. Creatures who have survived in the sewers for an extended length of time are assumed to be immune to both afflictions.

Gratings: Sewer gratings are stout, but many are often old and rusty. They could be permanently set into stone walls or set to swing open on pivots when unlocked.
Iron Gratings: 2 in. thick; hardness 10 (8 if rusty); hp 60 (30 if rusty); break DC IS (23 if rusty).

Illumination: Generally, there is no light in the sewers except beneath a sewer grate, where the filtered sunlight is equivalent to an immovable torch.

Scent: A terrible stench pervades the entire network, providing a -4 circumstance penalty on Survival checks for tracking when relying on scent.

Tracking: Walkway ledges are generally coated in a thin sheen of slime, making them "firm ground" for purposes of tracking.


Sewer Features

The following locales are shown on the sewer map.

Sewer Encounters

The sewers of Waterdeep are home to all manner of creepy crawlers, as well as bats, rats, and other various small animals. Many varieties of slimes, molds, and fungi are also found in the sewers, including brown mold, green slime, and yellow mold.

A wide variety of monsters are commonly encountered in the sewers as well. Many of these make their way through connections between the city's dungeons and the city's sewers. Many inhabitants of the city above also frequent the sewers, including members of the Cellarers' and Plumbers' Guild, merfolk from the harbor, solitary rogues, and various Agents of the Eye. Several unique creatures known to roam the sewers include the following: a deathshrieker created in the aftermath of Myrkul's destruction; the Eye itself (see The Eye), accompanied by a contingent of eyeball beholderkin and lurking stranglers; Xliilqil (LE doomsphere), who seeks revenge on the Company of Crazed Venturers for its destruction decades before; a long-missing contingent of the Cellarers' and Plumbers' Guild who vanished during the Time of Troubles (CN male cursts [augmented humans] commoner 1); and the Savants of the Dark Tide.


As a party travels through Waterdeep's sewers, every 30 minutes it has a chance for a sewer encounter, as set out in Sewer Encounter Chance. Groups moving at half their best possible speed or slower are treated as using cautious travel. Parties cloaking both sound and light use the hiding column. Passageways are considered to be primary, secondary, or tertiary, as noted above.

On the table, "Sewer Feature" refers to junction rooms, the immediate vicinity of sewer shafts, or other secret chambers (not shown) off a sewer passage. In addition, every time a party moves through a sewer feature, there is a chance of an encounter. If the party remains in a sewer feature for 30 minutes or more, there is a chance of an encounter coming to them every 30 minutes per passage connecting to the sewer feature. For example, if a junction room connects to a primary passage and two secondary passages, roll three times per half hour the party remains in the vicinity of the sewer feature.

PassageNormal TravelCautious TravelHiding
Sewer Feature25%20%10%

Random Encounters

Where appropriate, determine class, race, and alignment of each character by using the NPC generation tables in the FORGOTTEN REALMS dungeon Master's Screen or in the Dungeon Master's Guide.


Sewer Feature


Lands of Faerûn

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