What are the benefits to having a pond onsite?

We’ve got 5 acres that we are introducing sheep, goats and chickens to, as well as an orchard and veggie garden. I keep coming across people digging ponds on their properties and I wanted to ask, at a high level, what the benefits are if you already have wells (we’ve got two good producing wells)?

I can quickly think of two reasons:

The farmer does not have to fill a water trough as the stock can drink out of the pond.

The farmer can stock the pond with fish and go fishing instead of filling the water trough.

We put a natural swimming pond in the middle of front yard garden.  We are on a deep well for the house and we recently installed  a shallow well high up on our hill side.  The pond has a large shallow area that is full of pea gravel and aquatic plants that hosts 4 to 5 of frogs and toads.

Benefits of our current pond.  
A plunge pool to cool off in the heat of the summer.
The gutters of our house are hooked up to it so we don't have water pooling around our foundation during major rain events.  
We built a patio space next to it so we can chill out while watching the frogs, fish, birds, and dragonflies use the pond.
The frogs, toads, birds and dragonflies dramatically reduce the insect damage to my  veggie and fruit plants.  This work force is amazing and I want to add another pond to the backyard to get the same benefit.    
The pond over flow waters a swale and swale berm full of fruit trees and shrubs.  
I use the pond water for irrigation for the plants near the pond which reduces well water use.
I have a water source to use in a power outage.  While it would need to be treated to make it safe to drink it is a nice back up to flush toilets and such when the power is out.
My cat loves drinking out of the pond. He also loves all the critters the garden and pond provide for him to chase.  
You can grow edible fish in the pond.  We will be adding a second pond to our back yard and want to stock it with at least native catfish.
If you have a fire the fire department can use that water to help put it out.
It can help create season extending micro climates to keep slightly warmer loving plants alive over the winter. Our pond berm is one of the last places to get frost damage in the fall.  

Although we keep no animals other than pets (dogs and cats) we have an old 1/4 acre stock pond that was on site when we built the house.  The pond is a wonderful resource for all sorts of wildlife.  Deer visit daily.  All sorts of birds are attracted to the pond, including ducks and blue herons.  We also have a nice population of turtles that lives in the pond.

Eric

More benefits of our pond.  
Another benefit of the pond is the reduction of mosquitoes.  We thought we would have a bigger problem with them with the addition of the pond.  Since we built in lots of shallow areas for plants and other aquatic life the mosquito larvae have too much competition to thrive.  

My husband added a shallow gravel filled area with some bigger stones you can sit on with your feet in the water.  This area of the pond is an absolute favorite of children and dogs to play in.  

Ponds have many useful functions. There are a dozen or more in this forest. Some are natural, some are man made. Ranging from about 1 to 35 acres. Some are stocked some are not. One was built for cattle in the past. I think they provide a lot of benefits to animals & also have natural beauty. I enjoy sitting on my front porch at dawn & watching all sorts of wildlife coming to get a drink. I frequently see deer, coyote, fox, tortoises, & many types of waterfowl. There are some white herons that are almost like pets. Ponds help with flood control. They also can help with fire control in the event of a wildfire. The fire in this pic was part of a controlled burn though. Another very useful function is easy water availability in the even of long power outages. Where else can one use a baby fish cannon?

I watched that short beaver film on YouTube and I must say, if I moved, multiple ponds would be an absolute necessity at some point. They’re amazing as shown.