I live on an island in British Columbia and it does get high rain fall at times. It is hard to build soil here and it often is leaning a bit toward the acidic side. Over the years I have just used mulch. cardboard and at times of high rainfall during peak winter I will cover my beds with a tarp to minimize soil and nutrient leaching. Of course come spring you need to remove all of these things so the soil can warm up. You could also experiment with winter ground covers to build nutrients and hold your soil intact, this I find is the best method because its little input for a lot of action and output, of course depending on what you plant you will have to turn it over in the spring. Another factor to consider is what type of soil you have, A simple test can determine that( it can be found in the book the soul of soil) once you know this you can help the soil structure along by either building it up with organic matter (you should do anyway) or possible De-compaction of soils high in clay or that have been over grazed or over worked. My teacher gave an example of using a yoU bar digger or fork that can be found at lee valley or you could make one yourself. By simple just moving through the compacted area and just lifting the soil, not turning it, you get more effective drainage and aerobic activity in the soil.
I hope this has helped
