Staff working for Irish Water suffered 21 cases of assault or abuse in the past three years, records show.
They included threats with a machete, cars speeding towards them, rocks being thrown at vans and intimidation in the early hours.
There were 10 instances of aggression against staff or contractors working for the water utility last year alone.
The machete incident happened in Galway when a crew were threatened by an angry homeowner.
"The male was standing on his property waving the 500mm machete at the contractor crew installing boundary boxes in the footpath outside his house," it was reported.
Two attacks happened in Co Donegal on people working for Irish Water.
In March, "one of a contractor's traffic-management operatives was assaulted by a member of the public. Unsure if he needed medical treatment. The operative reported the incident to gardai".
The second attack came in June.
"Contractor operative was attacked by a stranger. Operative received several blows to the head before gardai arrived and arrested the attacker. Operative taken to hospital," the report said.
Three Dublin City Council employees working for Irish Water were verbally abused by a gang last year.
"While one individual shouted obscenities and referred to employees as 'scumbags', 'kn**kers', and 'Irish Water scum', another photographed their vehicles," it was reported.
In Tipperary, a "contractor operative was confronted by an aggressive member of the public who threatened and verbally abused him".
In 2018, five assaults or threats were recorded, including a sinister incident in the early hours in Dublin.
"The incident took place at 2am when gang of 4/5 persons questioned crew about their work and looked for ID," said the Irish Water records.
In Mayo in 2017, an Irish Water worker started to reverse her vehicle when she noticed a cardboard box had been placed against the rear wheel.
When she got out to remove it, she saw abusive graffiti had been daubed on the vehicle.
Six other incidents were reported in 2017, including a member of the public harassing a staff member on the phone then turning up at Irish Water offices to continue the abuse.
In north Dublin in March 2017, two cars, one silver, one red, approached a work site at speed.
"As the vehicles passed by, silver car swerved towards an operative. Operatives had to jump on to the bank to avoid the car," the report said.
"There were four people in the silver car and three in the red car. They started roaring down towards the crew."
The two cars crashed into each other, and the gang later returned to threaten the workers again.
In Limerick, a contractor who drove to repair a leak had his van damaged when children threw rocks at it.
Asked about the attacks and threats to employees and contractors, a spokeswoman for Irish Water said: "We have no further comment to make."