It is piped. At every house there is a shutoff box with a sediment filter. You're supposed to clean the filter annually, they announce when you can begin using it for the year and when they shut it off for winter so you can close the valve and not pop sprinkler heads while they pressurize the system in the spring. Another way they cut back usage is pressurizing the system later and later in the year.

I've seen people water on the wrong days all the time. I've also seen people use hoses from their houses to water on their off days. Which is kind of counterproductive as that water is the metered treated water, and the whole purpose of the irrigation system is to not use that for watering your lawn.

Oh and I forgot to mention that the golf courses aren't even profitable. They're subsidised by taxes to stay afloat because of corrupt city councils and idiots like those quoted in the article.