I live in Chiang Mai almost 3 years already and I love it. Not willing to move.

However, I miss doing some water sports, especially Kitesurfing or Windsufring.

Kayaking or white water rafting are not in my interest.

Any idea if somewhere in Chiang Mai province some people do kite or windsurfing ?

Probably your best bet would be to look at the local reservoirs and dams

They used to have windsurfing boards for rent at Huay Tung Tao, the reservoir near 700 year stadium. I saw them the first time years ago, but they may still be available.

Seems it's only swan-shaped paddle boats at the lake now.

apart from that, the nearest beach is way south of here...

Other than and a few perfect 15kt north wind days in January not enough consistency.

The only other time there seems to be any wind here seems to be associated with downpours and thunderstorms.

You're in the wrong county. If your able to find wind surfing here, I should be able to find a ski resort.