(A) Purpose. The provisions contained herein are adopted to protect public and private property from damage or destruction resulting from the natural erosion processes occurring within the ravines and bluffs along the shore of Lake Michigan, or abnormal or accelerated ravine and bluff erosion resulting from land development and construction activities occurring on adjacent or nearby properties, and to protect the fragile ravine and bluff ecosystem from unwarranted damage or destruction caused by land development and construction activities.
(B) Applicability. The provisions contained herein shall apply to all land development construction activities on all properties abutting ravines and bluffs as delineated by hashed lines on Appendix F.
(C) Requirements and restrictions.
(1) Building setbacks.
(a) From ravines. All building construction shall be on table land, but in no case shall any structure or building foundation be located closer than 20 feet to the ravine area.
(b) From bluffs. All building construction shall be on table land, but in no case shall any structure or building foundation be located closer than 75 feet to the bluff area.
(2) Construction activity.
(a) Adjacent to ravines. All construction activity; i.e., grading, excavating, filling, terracing, tree removal, stockpiling of excavated material, is prohibited within 20 feet of the ravine area, except as may be necessary to provide site drainage improvements, as may be approved and/or required by the City Engineer.
(b) Adjacent to bluffs. All construction activity, i.e., grading, excavating, filling, terracing, tree removal, stockpiling of excavated material, is prohibited within 50 feet of the bluff edge, except as may be necessary to provide site drainage improvements, as may be approved and/or required by the City Engineer.
(3) Site landscaping. Upon completion of construction activities, minimal grading and clearing of existing vegetation may be allowed within the bluff or ravine area in order to install new vegetation and lawn landscaping. However, no such grading, clearing or landscaping will be permitted within 20 feet of the ravine edge or within 50 feet of the bluff edge.
(4) Site drainage. A site grading permit, approved by the City Engineer, shall be required before any site grading work may take place. Measures shall be required to control stormwater runoff from impervious areas, lawns and footing drains. Wherever feasible, such runoff shall be collected and carried to established storm drainage facilities located away from the ravine or bluff area as the case may be. If discharge into an established storm drainage structure is not feasible, drainage shall be collected and discharged into the ravine channel or from the top of the bluff to its base in a manner which minimizes disruption of the ravine or bluff slope and potential erosion of the bluff slope and potential erosion of the bluff toe or the ravine toe and channel, subject to the specific approval of the City Engineer.
(5) Channel modification. Where the City Engineer finds that an unstable ravine or bluff slope or toe exists or is likely, or where the configuration of the ravine channel has resulted in erosion or suggests the probability of future erosion, channel, toe or slope stabilization measures may be required by the City Engineer.
(6) Required information. Prior to submission to the city of a request for tentative approval of a plat of subdivision or review of an application for a building permit, the owner or agent of the owner of property, subject to this section, shall submit to the City Engineer all applicable site information, including, but not limited to, topography, existing trees and vegetation, ravine and/or bluff conditions (including establishment of the limits of the ravine or bluff area), geological and soil conditions, proposed plans for landscaping and lawn installation, and such other information as may be deemed necessary by the City Engineer in order to implement the policy and requirements of this section.
(D) Review guidelines and approval procedures.
(1) The City Surveyor and Engineer may approve encroachments into the bluff or ravine setback area for the construction of landscape features, auxiliary buildings (slab foundation), bridges, wood decks or other similar facilities, if the City Surveyor and Engineer finds that:
(a) The proposed construction is appropriate only for the requested location;
(b) The proposed construction will have no significant impact on the ravine or bluff area; and
(c) The proposed construction is of relatively low value, except for items related to ravines such as vehicular bridges.
(2) The Zoning Board of Appeals may consider variations from the requirements of this section for construction of habitable facilities such as room additions or new residences, and construction of significant auxiliary buildings. In considering such variations, the following guidelines, in addition to the four findings of fact as set forth in § 159.042(F)(4)(b) shall be considered:
(a) Construction in the 20 foot setback for the 22 degree slope intersect could be recommended if there exists adequate toe of slope improvements;
(b) Construction in the 22 degree slope angle could be recommended if there exists adequate slope or other improvements that effectively increase the stable slope angle;
(c) Variation from building on land that exceeds 10% slope but is outside of the 20 foot setback from the 22 degree slope angle could be recommended if entire slope shows no indication of instability; and
(d) Variation from any restriction could be recommended if the requested construction is less nonconforming than the existing residence and the ravine or bluff slope does not show any indication of instability; or if the applicant submits evidence based on current geotechnical engineering practices such as the Simplified Bishop Method of stability analysis whereby variables of soil shear strength, ground water level, unit weight of soil and slope angles are considered which result in the determination that the particular slope is stable at an angle greater than 22 degrees.
(Prior Code, § 46-15) (Ord. eff. 1-15-1972; Ord. 91-1(A), passed 1-7-1991)