It depends on the look you want from your lawn :-) Some are very OCD about their lawns and insist they be only pristine, weed-free turf grass. Others - like myself - will allow in the infiltration of various plants other than obvious large weeds, like dandelions, dock or thistles. My lawn includes the aforementioned violets, lawn daisies, some sort of creeping veronica, some random patches of ajuga and wild strawberry, clover and creeping charlie. There are even a few hardy cyclamen that have seeded themselves around.

I also never water my lawn. It may receive some overspray when I water planting beds but otherwise, NO irrigation other than rainfall. And I live in a summer drought area with almost zero rainfall between July and October. I just allow the lawn to go dormant. It rapidly springs back to life in fall.

We have violets everywhere on our property. I have let them grow in shady beds under old tall evergreens, even transplanted them to those beds where they make a great ground cover. But I don’t let them invade the lawn. They die down for the winter and your lawn will look ratty and full of bare spots from Nov to May, and the winters aren’t as snowy now in 5b as they used to be, so not as much snow cover.

Is your lawn fairly shady? I'm having trouble with the idea of broad leaved shade tolerant plants being more drought tolerant than grass.

So I guess the first question is, why do you feel the grass needs to be watered?

I'm not sure violets would grow everywhere in a yard. I got a lot of them in some of the shadier areas of my lawn, but not so much in the open sun areas. Other stuff grows better in the sunny areas.

But like gardengal, I got all sorts of stuff growing all over in my lawn as well as grass. I try to encourage them, or wait if I can to give them some seed time.

I have some swaths of wild chives that I love to let grow- I get a good early spring crop of them for processing into a few things,. They have a nice flush above everything else starts growing up, so makes picking them clean easy. Every year the swaths grow a bit more.

I wish I knew an easy way of sowing in a bunch of little crocus bulbs. I'd do in a bunch in the very front yard down by the road.

I have a ton of violets in my yard. I just mow them after they bloom. If you don't water much and mow, your yard will end up full of stuff that can survive your treatment. It won't look like a picture postcard lawn, but it should be green and walkable.

I had Vinca years ago. It's not native, invasive and grows too high to walk on. I suspect it doesn't handle mowing well, but I never mowed mine.

Vinca starts looking ratty here in Northern NV without a lot of water in the hottest summer months.

have you thought about a Buffalo grass? or similar. (No personal experience myself but is looks interesting)

my experience has been that violets will take over, even where you don’t want them, and are difficult to get rid of once that happens (zone 4a Ontario).

Do you have neighbors who wouldn't appreciate having their lawns perpetually invaded by your violets (because, they are aggressive, spreading both underground and by above ground seeding)? Not that they really have a right to dictate what you do... but something to think about.

Vinca is a bad idea as explained above. You might look into an herbal lawn as an alternative (IDK what would be good for your zone and climate).

My front lawn is entirely turf type tall fescue. I never water it, I only treat it with corn gluten meal, and it is thick and weed free - occassionally something will pop up along the edges, taken out in seconds with a knife when I am mowing. I do have to mow every 5 days or so however.

@raee_gw zone 5b-6a Ohio I think my violets spread from my neighbors who have let them run rampant :p I do have vinca elsewhere and was thinking to just.....let it grow and not mow. It's an incredibly sloped and shaded east facing front yard so walking on it would be minimal. I thought the violets were cute but I think I'm inclined to opt towards something that'll play nicer with others. Maybe clover :p

How big an area do you have? Maybe post some pics and then perhaps you’ll get some suggestions which may, or may not, be better than what you have...?

Shady, sloped and not for "lawn" use - I might plant a mix of lamium and some other spring blooming perennial plants (like pulmonaria and bulbs), and let the violets and vinca do their thing.. I actually have this in a couple of shady beds - the other plants grow happily through the vinca so they provide some color and interest, the vinca is green through winter, and no maintenance other than yanking out an obnoxious weed once in a while and trimming the vinca around the edges once a year to keep it in bounds.