The region in which you will be sent has really not been created for a calm life of Jupiter. A swampy river, few building land, cold weather and intractable Gaul. But you are accustomed to worse.
Build in the Roneum-Delta as fortified as possible a north-wester base, maybe with a small garrison. Most of all one thing: fullfil the demands of Rome. Times are hard and lot of people are only waiting to capture your post!
Do take care of one building: the pump station. You will have no possibility to establish another pump station on top of the hill or anywhere else because the experts from Rome are not available. Moreover the river with its dirty water is not suited for supply.