You could sue your neighbor for nuisance.  Nuisance is a serious and unreasonable interference with the use or enjoyment of your property.Damages (monetary compensation you are seeking in a lawsuit) would be an inadequate remedy because of multiplicity of lawsuits as the flooding of your property is an ongoing problem.  Damages are also inadequate because land is unique.When damages are an inadequate remedy, you can pursue an equitable remedy which in this case would be an injunction.  A court will balance the benefits and burdens to the parties in deciding whether or not to grant an injunction.  The benefit to you of not having your property flooded will be balanced against the burden of the cost to your neighbor of preventing the flooding with a drainage ditch or some other measure to stop the flooding.The court may grant a temporary restraining order which would be in effect until a preliminary hearing, at which time the court will determine whether to grant a preliminary injunction which will be in effect until trial, at which time the court will determine whether or not to grant a permanent injunction.