If you're planning a development anywhere near a stream, a drain, a piece of wetland, a lake, the ocean, native vegetation – pretty much anything other than a grazed paddock suburban street – you’re likely going to need to engage an ecologist. That ecologist can tell you whether the natural features present are something that you need to work with and protect, and how to do that. It's important to get advice from an ecologist early because that helps avoid costly redesigns later in the process, and the associated time delays.