These three writing rubrics are staples in my fourth grade ELA classroom. We use these for each of our final pieces turned in for our portfolio. Each rubric is aligned to the common core writing standards for opinion, explanatory and narrative writing. Each rubric also includes a section for scoring L.4.2 (which applies to grammar and convention use within writing pieces).
I hope these three rubrics will become your go-to when it comes to setting expectations and grading fourth grade writing!