But what happens when you find your Hydro Plant not working or operating? Well, read on for some general tips to prevent this from happening and what to do when – or if – it does.

Where Do You Need to Build Your Hydro Power Plant? 

To build a Hydro Power Plant (or Dam), you need to have reached a population of 12,000 in your city and have access to flowing water. There are a number of maps that have rivers as standard pieces of the environment, or you can make your own using Cities: Skylines’ terraforming functions.

One of the first things you need to be looking for when placing your Hydro Dam is the level of the land on either side of your river. Ideally, you should be placing it where there are cliffs or high embankments. If you place it near low-lying land, you risk flooding the surrounding area.

Next, you have to take into consideration the flow of the water you wish to build across. A stretch of water with bigger arrows denotes a fast flow. For smaller stretches of water, big arrows are key to water flow, but if you wish to build across a very wide bit of water, flow strength isn’t entirely crucial. Here, the sheer volume of water flowing through your Hydro Plant will compensate for the water’s slower flow.

Water flows at different strengths in Cities: Skylines. 

I Think I Have Found a Good Place, But Now My Dam Isn’t Operating

The big thing to remember when building a Hydro Plant is that the effect is not immediate. Reports from Reddit and Youtube suggest that it can take as much as 5 mins of IRL time for the Hydro Dam’s mechanics to kick in and the plant to start generating electricity.

During this waiting time, lots of things can happen. Every time I placed a dam in one of my simulations, it triggered a tidal wave. This is one of the reasons for building your dam in a rocky area. If I hadn’t already protected part of my city with flood barriers, I would have had residents under water. Luckily, water does disperse, so it wouldn’t have been forever.

Placement is absolutely key, so what could also be happening when your Hydro Plant doesn’t work is that the dam has been placed near the mouth of a lake. Even though the graphics might show that there is a strong current coming out of the lake, at the end of the day, a lake does not have a constant supply of water. This might mean that the water flowing through the dam might just stop.

The Reddit image below shows what happens when a dam appears to not be working. While it may look like you need to change things around a bit, start with waiting a while to see if everything kicks in before destroying the dam and potentially causing some catastrophic event for your city.

Image posted on Reddit by user Linkery


I’m hoping that this has given you some hints as to how to place your Hydro Plant dam and how to avoid any issues that may occur with your Hyrdo Plant not working. Make sure you check back to GameSkinny for more tips and tricks for Cities: Skylines.

Make sure to check out our other Cities: Skylines guides and fixes below: 

Got Dead Bodies Piling Up In Cities: Skylines? Here’s the Fix!  Cities: Skylines Mods Not Showing Up? Here’s How to Fix It!  Cities: Skylines Mass Transit DLC Transport System Guide Cities: Skylines Mass Transit Traffic Guide