Hello and thank you for your question. I will be very pleased to assist you. I'm a practicing lawyer in England with over 10 years experience.
From what you say am I correct to say that you have not modified your land in any way that has led to run off onto their land but rather this is a natural occurrence resulting in water draining onto your neighbours land please?
The legal position is that if the run-off is being caused by natural flow of water across or under the neighbouring land then they have no redress against the you just becausethe water happens to source or run across your land. However if it is being caused by activities or modifications to your land which from what you say is not the case then they do potentially based on the duty of care they refer to
In the event of a dispute a surveyors report can be required to clarify the position as to both source and the reason for drainage. If the neighbours wish to make a claim against you then it is for them to seek evidence against you to show that drainage onto their land is being caused by works you have carried out to your land.
If they can demonstrate such evidence then they may be able to fashion a claim against you but in the absence of evidence of water running onto their land other than by natural means, they would not have the basis of a claim against you as you are not liable for natural water flow off your land.
In these circumstances it is up to you either to come to a joint arrangement or make your own separate arrangements as you each see fit
Is there anything above I can clarify for you?
She would appear to be relying on the (from what you say) incorrect presumption that the drainage is being caused by works you have carried out. If this were the case she would be absolutely correct potentially. However there is no case law I am aware of that has made a landowner liable to neighbours for natural water flow
You may consider putting her to strict proof and cite specific authority by reference to legislation or case law if she believes she knows otherwise. I will be happy to look at any references she provides though I cannot see she will be able to supply anything substantive.
A pleasure. If I can assist any further as the situation develops please do no hesitate to let me know.
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