‘Selfish next-door neighbour killed my plants. Can I sue?’

Dear Eileen,

It never fails to surprise me how unthinking some neighbours can be. Bad behaviour does not always equate to unlawful behaviour, but in this case I do think you have legal grounds for taking this further, if so you wish.

Unless it is diluted adequately, chlorine can indeed be toxic to plants – including lawns. 

And I do not wish to alarm you, but chlorine can also permeate concrete and corrode any steel inside, and can therefore have an adverse impact on the integrity of concrete structures, such as garages and exterior steps.

The first avenue to explore is criminal damage under the Criminal Damage Act 1971. 

Criminal actions usually require an intention to carry out the offence, but with criminal damage it may be deemed to be committed “recklessly” when a person knows a risk exists and, in the circumstances, it was unreasonable to take that risk. 

In your situation, this would involve Mr Big House knowing there was a risk your garden may flood if he discharged his swimming pool water in your direction (seems an obvious “yes”), and it was unreasonable for him to take that risk (again, the outcome speaks for itself, and the fact he directed the water in your direction goes against him).

 So, you could see if the police will go and talk to him on this basis. 

The police will appreciate seeing the log of the incident kept by the fire service. Ask your friendly firemen to disclose that to you, and give it to the police. The log is contemporaneous evidence of what happened when, and who was responsible.

If the police pursue this, justice may be served that way. And it will set up a civil claim, if you decide to bring one.

Mustering any civil claim has a cost risk to all involved. To protect your position in this regard, check if your home insurance policy includes cover for legal expenses. 

If it does, you should be able to get an indemnity for the cost of exploring the case to sue Mr Big House, in that the policy will cover that cost. This could be a big win for you already, as it is a tactical advantage against any opponent who has to pay their own costs.

To sue successfully you will need to show a direct connection between the dead plants and the chlorine. This is not necessarily a straightforward task. 

Again, the fire service log will be helpful, but you will also need some kind of robust expert evidence from a horticulturalist to confirm that the plants have died because of the chlorine – or at least that chlorine in certain quantities will kill plants (which I believe is uncontroversial). 

You will also need to quantify your loss, in terms of putting together a cost to replace the plants and any connected work. For instance, this could include paying someone to re-plant if you are no longer able to endure that physical exertion.

Although you have asked me “Can I sue?”, I appreciate that being at the centre of full-blown civil litigation may not be what you are seeking. 

Hence, seeing if the police will intervene is, in my view, the optimum way forward. And even if there is not sufficient evidence to prosecute for criminal damage, asking the police and fire service to speak to Mr Big House and put him “on notice” may be a deterrent for future bad behaviour. 

One last avenue to explore is the retrospective planning permission granted for the swimming pool. 

Your gut feeling about it not being constructed without proper drainage may be correct, and raising your fears with the planning authority would be prudent. 

It is common for outdoor swimming pools not to require planning permission, so maybe Mr Big House needed permission because his house is listed, or in a conservation area – or maybe he has an indoor pool (you do not say either way). 

But if it is subject to planning laws conditions may have been imposed about drainage, which should be explored.

Whatever you decide to do, I hope your garden recovers soon. 

Email your legal questions to Gary: askalawyer@telegraph.co.uk