Construction of a new stormwater collection system in East Spokane is forcing closure this weekend of South Thor Street at Hartson Avenue starting at 6 p.m. Thor will be closed to through traffic starting at Hartson and extending up the South Hill on Ray Street to 29th Avenue. Local traffic can access neighborhood areas during the construction in the vicinity of Eighth Avenue. Freya Street will be used as the detour route for through traffic. The closure will last until Sunday evening. On Monday, crews will close Freya Street at 6 a.m. from Hartson to 29th while work moves to that location. Again, local traffic can access Freya south of the construction zone. Ray and Thor will be the designated detour route. The Freya closure will last until the end of August because of a need to make multiple utility improvements, including installation of a stormwater collection and delivery pipe. A new stormwater retention tank has been installed at Underwood Park to the west. City officials said the closures will likely result in motorists cutting through on neighborhood streets, so extra caution is advised during the closure periods.