Building a pond from scratch can seem a daunting task however it need not be, having the correct equipment and understanding what form of pond will suit your needs is half the battle.
The first thing to consider when you build a pond is where it will be located, try to view where the pond will be from many different angles, try looking from an upstairs window also, use what ever you have to mark out a make believe pond so you can see it from different angles.
You need to consider the size of your pond, this will be affected by the size of your garden and what you are considering to have in the pond. A larger pond would be needed for larger fish such as koi carp where as a smaller pond would suit goldfish or if the pond was just for newts and frogs.
Once you have defined the parameter of the pond (this is often done with string or hosepipe) and you are happy with the size and positioning you will need to excavate the area. Dig out the turf and keep going until the required depth is achieved, remember to remove any sharp stones or large lumps of mud.
When digging the pond it is recommended that you leave one side with a slop so any animals that accidentally fall in have a way of getting out, it is also a place where you fish can bask in the sun.
Once you have dug the pond you will need to lay a base, if you decide to use concrete then you will need to add some sort of wire to it to bind it together and prevent it from cracking, sand is another option, lay a layer of sand around the hole you have dug, this will protect the pond liner and help to prevent it from being punctured.Adding a layer of old carpet adds to this protection.
Once the base has been laid you need to position your pond liner, this will require some help depending on the size of your pond. Ask a friend to help with this part, hold each end and lay over the hole you have dug out, take care not to damage the liner by dragging it over rough ground or sharp stones.
Once the liner is in place secure the sides with some bricks and most importantly leave plenty of overlap.
Once the liner is in place it is time to start to fill your pond, as the pond is being filled it is important to pull the edges of the liner so it fits neatly in the contours of the pond.
Keep adding water until the pond is full then cut away any excess liner leaving an overlap large enough to lay slabs or turf on to keep in place.
Stand back and have a look at what you have created!, Now you have the job of decided which fish and plants you will add and position around your new pond.