1171.13 PRESERVATION OF NATURAL FEATURES, TREES.
   Natural features, brooks, lakes, hilltops and other focal points within a subdivision or development, and distant views outside the subdivision or development shall be integrated in the design to obtain natural variations and interest in each neighborhood, Trees, topsoil and other natural resources or existing features that would add value to the development or to the City as a whole shall be preserved and utilized in the development or subdivision to the extent practicable. The Planning Commission may require that as many natural features as can be reasonably utilized in the final development plan be retained and that the grading be adjusted to the existing grade at the trees.
(a)   All trees to be retained shall be protected during construction according to the following:
(1)   Tree Protection Zone. The development plan or subdivision plat shall show the number and location of existing trees as required by these regulations and shall further indicate all those marked for retention. All trees to be retained shall be included in the tree protection zone and such zone shall be designated on the development plan or subdivision plat.
A.   The trees protection zone shall at a minimum encompass the critical root zones of all existing trees.
B.   The critical root zone is a circular area surrounding a tree, of which the center is the center of the tree trunk and the radius is the distance from the outside of the trunk to a point twelve times the tree’s diameter at breast height (DBH), which points constitute the circumference of the critical root zone.
C.   The critical root zone shall extend to a depth of five feet below surface ground level.
(2)   Placement of Tree Protective Barriers. On the site, trees within the tree protection zone shall be protected according to the following:
A.   Prior to construction, tree protective barriers shall be placed around all trees to be preserved and any other vegetation that is located near construction activity and which is to be saved. These barriers shall be located so as to totally encompass the perimeter of the tree protection zone.
B.   Protective barriers shall remain in place until construction is complete, landscaping is installed, and an occupancy permit has been issued.
C.   No land disturbance, including grading or filling, shall occur within the tree protection zone except as may be approved by the Building and Zoning Inspector and the Engineer when an aeration system is installed. Commercially available aeration systems are subject to approval by the Building and Zoning Inspector.
D.   Areas within the tree protection zone shall be free of all building materials, dirt, chemicals (including gas, oil, and contaminated water), construction debris, vehicles, and development activities.
(b)   Land that the Planning Commission finds to be unsuitable for subdivision or development due to flooding, improper drainage, steep slopes, rock formations, adverse earth formations or topography, utility easements, or other features that will reasonably be harmful to the safety, health, and general welfare of the present or future inhabitants of the subdivision or development and/or its surrounding areas, shall not be subdivided or developed unless adequate methods are formulated by the developer and approved by the Planning Commission, upon recommendation of the Engineer, to solve the problems created by the unsuitable land conditions. Such land shall be set aside for uses as shall not involve any danger to public health, safety and welfare.
(Ord. 1997-117. Passed 9-16-97.)