Xjyuk

It's a coastal city with lots of sunshine in a modern setting. You have everything you need and more. All you have to do is desalinate the water and it's done. Took less than a minute research.

OK, you have to scale it a little better than in the link.

Channel the seawater to shallow fields, coated with water resistant foil to prevent seeping it to the ground. It should be a few cm water in each field. Transparent vinyl (or what it's called) close above it. It lets through the sunlight, speeding up the water evaporation. The vinyl catches the evaporated water droplets and with a slight tilt, they will flow to a prepared storage (or the agricultural fields). The salt remains, which they have to collect, but they can sell it for good money.

The amount of water is only dependent on the size of the fields.

An extreme possibility, which requires some suspension of belief: This town lives in a small plain surrounded by mountains. Local winds bring heavy fog 24/7 which is trapped in large collector/condensers.

Well, even if there is almost no rain, there still may exist some rain. People can dig large holes or build containers in which they store water from rainy periods and use it along the year.

Also, it's possible for the desert to have underground water sources that can be accessed via wells.

One other thing that I could think is the use of plants. Desert plants are good at retaining water, so maybe you could have a special plant that can get water from very lower levels in the soil and be used as a water source.

Many of this can change according to other aspects of your geography, of course, like mountain ranges and hidden underground water sources.

Qanats.

https://whc.unesco.org/en/list/1506

https://en.wikipedia.org/wiki/Qanat

A qanat or kariz is a gently sloping underground channel to transport
water from an aquifer or water well to surface for irrigation and
drinking, acting as an underground aqueduct. This is an old system of
water supply from a deep well with a series of vertical access shafts.
The qanats still create a reliable supply of water for human
settlements and irrigation in hot, arid, and semi-arid climates, but
the value of this system is directly related to the quality, volume,
and regularity of the water flow. Traditionally qanats are built by a
group of skilled laborers, muqannīs, with hand labor. The profession
historically paid well and was typically handed down from father to
son. According to most sources, the qanat technology was developed in
ancient Iran by the Persian people sometime in the early 1st
millennium BC...

Qanats are super duper cool. They are ancient engineering marvels which still do what they are supposed to do millennia later. These underground aqueducts move water from distant sources (often miles away!) to arid lands and offer a bunch of side benefits - in addition to clean water, qanats can provide cool air. Read on how having a qanat pass under your house offers cool air pulled up thru the house via a chimney.

Behold! A time-tested method for desalinating water

Wiki how shows us a modern method similar to that I used as a teen in the Scouts. (Image from Wiki How.)

The process is simple: evaporate the salt water and let it condense on plastic, then drain the plastic someplace useful.

Here is a video showing how to do it with some plastic bottles found on the beach.

Here is a video showing a larger operation.

This system can be easily scaled so long as you can support whatever material is being used to condense the water. Honestly, it's conceivable you could do this over whole acres, letting in seawater through a gate and draining into a cistern.

Assuming your oceans are salt water, these are a few ideas that occurred to me:

Use wide-bandgap semiconductors to perform photo-electrolysis -- separating the hydrogen and oxygen using photons ( 2 photons + 2 H2O -> 2 H2 + O2 ). This is a technical possibility today, the development to make it engineering solution is still in progress. Then, ignite the gases and you have pure H2O again.

Evaporators:
The village has dug channels for water at high tide to fill wide shallow ponds enclosed in plastic tarping. The heat of the sun evaporates the water, leaving the salt behind, then water is condensed in shaded metal tubes that act as heat exchangers -- looks like large stills

Orthographic lifting + modified natural caves + passive heat exchangers:

The village sits on a wide peninsula surrounded by mountains that funnel the air higher and higher to a canyon or pass at the top. The mountains are honeycombed with natural caves, that people extended using explosives so they open on the other side of the mountains. The moist winds cool as the rise and pressure drop -- a consequence of orthographic lifting -- and air going into the caves is cooled further. The water condenses in underground reservoirs. This all only works because of the strange and unique geography and limestone or sandstone mountains in this area.

If the city is located close to the sea, the winds blowing from the sea inland will carry some humidity.

Overnight the falling temperatures can lead to the humidity condensing, therefore a series of drapes oriented parallel to the wind direction can act as condensing surface, letting then the water flow into channels to a reservoir.

Actual solutions used in the coast of the Atacama desert:

• 
  Fog collection. The wind from the sea does bring some water, which you can collect, but it's limited, not very scalable.


• Desalination of seawater is still expensive, not very scalable. You can lower standards (taste, purity) to get a little more water, which could fuel your conflicts. Military sea vessels get water through desalination, using a combo of temperature, osmosis and pressure (thanks to their engines).

Other:

• Pipes from oases.


• Underground streams.


• Water trucks.

All in all, current technology will limit your settlement's population, unless you can bring water with pipes or something else.

FWIW, cities in the Atacama desert rely on external sources, and need to ration water.