The wind did not do the damage based on what you write: it was done by flooding due to the pumps going offline. Whether or not they went offline due to wind damage to electrical lines, the fact is that the wind still did not directly cause the damage. If the wind did not cause the damage, the insurer does not need to treat it as wind damage. The fact that the damage was due to two intervening non-wind factors--rising water; and the pumps not working (which could potentially have been remedied by your getting a generator, getting battery back-ups, getting a shop vac operated by a battery or by current from your car and using it to keep ahead of the water, etc.)--breaks the causal link to the wind sufficiently as to justify them not paying.