The provisions of this chapter constitute regulations and provide for matters which affect and relate to the sanitary control of the water supply reservoirs and tributary watercourses for the city. Where applicable, they are effective within a radius of 5-1/4 miles from the intake of the company within the drainage area, with the upstream limit of Reservoir No. 2 at the center line of the Dixie Highway Bridge over the North Fork River at the foot of Seaton Hill, all in Danville, Blount and Newell Townships. ('64 Code, § 36-2)