hi and welcome if it was me i would move some of the old water into the new pond.there will be all sorts of benificial insects and things in the old water. also it would help the new pond to mature quicker.but thats only me others may tell you different.good luck.

All Newts have special protection under Law in the United Kingdom. You need to get advice from the local council before you damage, destroy or disturb your Newts, otherwise you can be prosectuted as they are considered to be very rare. It is illegal to catch, touch or disturb them in any way! It is illegal to damage their habitat as well.
If your old pond needs moving you will have to make a very strong case to the council, I'd advise talking to the authorities first. Hopefully for you they will adopt your new pond but as they return each year to their "home" pond you might not get very far.

Hi Kennyboy
Thanks for your comments. I think I will probably follow your advice but will wait to see other comments as well.

Hi Crv1963
Thanks also for your comments. As far as I am aware, the law in the UK currently states that you may not sell or trade newts. I believe what you are referring to only applies in Ireland.
I do, however want to preserve the newts as I am a keen conservationist. I just want to get it right and welcome any advice to enable me to do this.
By the way, two newts have now taken up residence in the new pond so I am already hopeful!

It may pay to visit the website www.overthegardengate.net/wildlife/frogs and newts to identify which species you have. Good luck!

The Smooth Newt is increasingly valued in garden ponds (usually arriving out of nowhere) as garden ponds have become increasingly important for Newts and Frogs due to the loss of countryside ponds and/or pollution.

Smooth Newts (Common Newts) are protected by law in Great Britain against being sold or traded and in Northern Ireland they are fully protected by prohibiting the killing, injuring, capturing, disturbance, possession or their trade.

Garden ponds don't usually require planning permission in the UK
My real concern is when to move or alter a pond? better to wait as spring/early summer is their breeding time in the ponds and disturbing them then could results in more losses than usual.

Thanks for all the comments - just to be specific, the new 'pond' is in exactly the same location as the old one. The old 'pond' was in fact a water storage tank sunk in the ground. The new pond is a much larger dug out pond with a liner. The tank still exists adjacent to the new pond and contains the original water and smooth newts. I take the point about the timing of this.
My original question was really about whether there was any value in transferring the old pond water which is currently green and a little slimy?

I think most people reuse pond water and certainly all the advise I could find was about conserving and reusing this water in a new pond. If you are in a hosepipe ban area you will not be able to fill it via a hose anyway.