Drain water for fruit trees

We have a couple of avocado trees that bear lots of baby fruits. I expect rain to be little by this time until June. The leaves are yellowing and falling some fruits are also falling I want to save I much of it. since we are washing clothes 15 meters from the tree, I can make the water for washing clothes drain to the trees. My concern is since wash water will have soap, will it harm the soil ecosystem?

I think it may depend on the kind of soap. There are natural soaps which easily break down or decompose and are safe for gardens and soil, and then there are not so natural soaps with chemical degreasers and surfactants, even harsh phosphates, and these kinds of soaps and detergents I myself would avoid putting anywhere I'm trying to nurture soil. A lot of detergents, and sometimes soaps depending on the ingredients, are alkaline, and can quickly alter a soils pH.

As James said, it depends upon the soap being used. I use a fairly mild detergent and no bleach or fabric softener for my laundry. I discharge both the wash and rinse water onto my trees. I have not seen any detrimental effects yet from doing this for the past 40+ years. But I do move the discharge hose around so that it is not discharging the water in the same spot day after day. Where I'm living right now I use the laundry water to irrigate banana and pineapple plants.

Like James and Sue said, with mild or biodegradable soaps you should be safe, it's also worth noting that many natural soaps and detergents are super basic (high number pH) and contain phosphates. This can be a real benefit for acidic soils and fruiting plants (like your avocado trees) so with some planning you can turn your laundry chore into a serious benefit for your orchard.

Thanks everyone for the advice. I will use clean water for now. We are still using the store bought soap. Maybe its time to make soap.