Hey guys I'm a relatively new GM and am looking for some advice on how to make a group trudging through a sewer entertaining. So far I'm planning on having one combat situation in it but beyond that all I have thought of is somethings like the roof collapsing(as the sewers are relatively old and dilapidated) and some jumping checks to get over some disgust deep sewer water. So any and all advice would be greatly appreciated thanks in advance to anyone that helps.

How about the refugees that have camped in a large junction with raised areas, needing food and medical assistance as well as help finding some foragers that went missing. They know the tunnels well...

Lots of chances for all kinds of skills:

Coordination due to slippery footing: failure = Strain, enough Threat might require a Resistance roll against disease

Stealth: setbacks from splashing

Skulduggery: get past a rusty grating

Computers: there are old waste monitors, maybe they can be rigged to trigger a sluice opening

Negotiate/Charm/Deception/Coercion: see orcface999's post

Survival: how to avoid certain animals, both small...and large...; also for navigating and figuring out where certain passages lead

Mechanics or Education: determining the purpose of equipment or how the passages are constructed

etc

Thanks for the help guys that gives me a lot of things to think about and work with greatly appreciate your advice.

Don't forget adding setback dice.

It's Star Wars... throw in a monster

My guys don't like having tons of fighting only like 2-4 encounters per session and I already have an fight that's gonna happen in them they are going into the sewers to find someone that has been captured by some slavers who are hiding out in the sewers. But maybe falling into some sewerage and having a monster pull them down so they have to make an Athletics Check to escape so again thanks for that idea never even crossed my mind until i ready your post DidntFall.

Courageous rodents steal supplies from their packs and belts when they aren't looking, which leads to a short but eventful chase as the character tries to retrieve their lost lightsaber from the sewer-rat. Something brief but a little more light-hearted than "surprise sewer squid!"