This article confronts present main stream planning approaches against the perspective of ecological sustainability, as relevant for Rule of Law countries and based on a modern environmental law approach. It discusses the setting and implementation of environmental goals against the general experience of massive implementation deficits regarding environmental policies all over the world. In this confrontation, environmental planning, with at least some principles picked up from New Zealand's Resource Management Act, and much more taken from modern environmental law theory on legal operationalisation, is compared to adaptive management approaches which also allow for modifying the environment related goal if implementation fails or seems very difficult. The concept of adaptive environmental planning (AEP) is suggested as a possible road to choose for planning for sustainability, while maximizing development within the framework legally defined by means of environmental limits. This article presents five criteria, all of which must be met by AEP planning. One of these relates to a planning hierarchy which, among other things, leads to the conclusion that coastal planning, if it is intended to aim at sustainability, can not be dealt with in isolation, although such planning might have to meet very complex problems at the regional level.