Here are just a few quotes from his The Climax of the Covenant that show that he is definitely looking at justification differently than the traditional reformed view (but I think it is a far stretch for Waters to say he is Semi-Pelagian)…
Justification by faith is “covenant membership demarcated by that which is believed.” (2) In other words it’s about Gentiles not needing to follow the Torah and it’s boundary markers (circumcision, kosher food, and Sabbath) to be a member of the covenant (3).
Paul’s purpose is missed when Romans is understood as about “individual salvation rather than as a treatise on the nature of the people of God.” (252)
“Here is the doctrine of justification, as it appears in Romans 9-11: Christian faith alone is the index of membership (10.4ff; 11.23).” (255)
With monotheism (God) and election (people of God) the core beliefs in the Jewish worldview, Paul inherits these and reinterprets them in light of Christ. Such that Wright states: “I have argued that christology is, for Paul, a means of redefining the people of God, and also a means of redifining God himself.” (266)
…but I didn’t come across (yet) any of his statements about the role of works in a christian’s life.
However, Wright definitely thinks that Christ came to deal with sins that we couldn’t. Referring to Rom 5.12-21, he writes: Christ “had to deal with the ‘many trespasses,’ and the consequent judgment, which had resulted from the sin of Adam. Thus there comes about also in v.16 the further contrast of judgment and justification. The work of Christ does not merely inaugurate a new race of humanity, as though starting from scratch. It effects a favourable verdict for those who, left to themselves, would be in the dock, unable to find a defence (3.19f.)” (37)