21 A surveyor in establishing in a concession in a single front township a side line of a lot that was not surveyed in the original survey shall proceed as follows: 1.  If intended in the original survey, the surveyor shall establish the side line on the same astronomic course as the boundary line of the concession at the end from which the lots are numbered, or, if such boundary line was not surveyed in the original survey because it was wholly broken by a lake or river and if intended in the original survey, the surveyor shall establish the side line on the same astronomic course as the boundary line at the other end of the concession, but where a proof line was surveyed in the original survey, the surveyor shall establish the side line on the side of the proof line that is farthest from the end of the concession that is intended to govern the course of the side line on the same astronomic course as the proof line. 2.  If not intended to be established on the same astronomic course as the boundary line at either end of the concession and if intended in the original survey, the surveyor shall establish the side line at the angle with the boundary line at the end of the concession from which the lots are numbered as shown on the original plan and field notes, or, if such end was not surveyed in the original survey because it was wholly broken by a lake or river and if intended in the original survey, the surveyor shall establish the side line at the angle with the boundary line at the other end of the concession as shown on the original plan and field notes, but where a proof line was surveyed in the original survey, the surveyor shall establish the side line on the side of the proof line that is farthest from the end of the concession that is intended to govern the course of the side line on the same astronomic course as the proof line. 3.  If the end boundaries of a concession were not surveyed in the original survey because they were wholly broken by a lake or river, the surveyor shall establish the side line at such angle with the front boundary of the concession as shown on the original plan and field notes, or, if parts of the front boundary of the concession have been surveyed on different courses, the surveyor shall establish the side line at such angle with the course of each of the parts as shown on the original plan and field notes, or, if such angle is not shown on the original plan and field notes, the surveyor shall establish the side line at such angle with the front boundary of the concession as the Minister may direct. 4.  If the end boundaries of the concession were not surveyed in the original survey because they were wholly broken by a lake or river and a proof line was surveyed in the original survey, the surveyor shall establish the side line on the same astronomic course as the proof line. 5.  If the end boundaries of the concession were not surveyed in the original survey because they were wholly broken by a lake or river and two or more proof lines were surveyed in the original survey, the surveyor shall establish the side lines that are between the township boundary from which the lots are numbered and the second proof line from such boundary on the same astronomic course as the first proof line from such boundary, and the surveyor shall establish the side lines that are between the second proof line and the third proof line from such boundary on the same astronomic course as the second proof line, and the surveyor shall establish the side lines that are between the third proof line and the fourth proof line from such boundary on the same astronomic course as the third proof line, and so on through the concession. 6.  If the concession is wholly broken in front by a lake or river and no posts were planted in the original survey on the banks of the lake or river to regulate the widths in front of the lots in the broken front concession, the surveyor shall establish the side lines in such broken front concession in accordance with this section from the corners of the lots on the front boundary of the concession in the rear thereof to the lake or river. 7.  If the concession is partly broken in front at either end by a lake or river and no posts were planted in the original survey on the banks of the lake or river to regulate the widths in front of the lots broken thereby, the surveyor shall establish the side lines of such broken lots in accordance with this section from the points on the rear boundary of the concession determined by dividing proportionately as intended in the original survey the distance between the end of the concession and the intersection of the last ascertainable side line with the rear of the concession as shown on the original plan, but where such end of the concession is wholly bounded by a lake or river and no measurement was made in the original survey along the rear of the concession to the lake or river, the surveyor shall determine the points from which the side lines of such lots shall be drawn by measuring along the rear boundary the widths of the lots as intended in the original survey from the intersection of the last ascertainable side line. 8.  If the concession is partly broken in front by a lake or river and the lake or river does not extend to either end of the concession and no posts were planted in the original survey on the banks of the lake or river to regulate the widths in front of the lots broken thereby, the surveyor shall establish the side lines of such broken lots in accordance with this section from points on the rear boundary of the concession determined by dividing proportionately as intended in the original survey the distance between the intersections of the last ascertainable side lines on both sides of the lake or river with the rear boundary of the concession.  R.S.O. 1990, c. S.30, s. 21.