Actually the link above doesn't go to the article which I believe the poster intended it to go to, as the article on Business 1 changes from day to day. Yesterday's Business 1 article is now archived
here. Now if the contents of that linked web page doesn't change then it should take you to the correct article.
To summarize: Heavy rain sends sewage from a break in a main sewer line into Kalapaki Bay, beach closed. Yes the Kauai Marriott Resort & Beach Club is on Kalapaki Bay so their beach would be closed.
FWIW, I stayed at this property a few years back. While the grounds of this property are beautiful, the pool is the largest, the restaurant and services OK to good, the rooms at this hotel are very mediocre and dated, and I did not used the beach or go into the water as neither were appealing. Now, I scuba dive and love beaches and frequent many throughout the world so it is not like I don't do beaches. There was just something about it, like it wasn't clear, it wasn't turquoise, and there was an industrial feel to it. BTW, the stunning courtyard at this hotel brings a entirely new meaning to the term "Marriott Courtyard".