A. Existing Structures and Related Improvements. Structures and related improvements that were legally built or vested prior to the effective date of the ordinance codified in this chapter that do not meet the requirements of this chapter may continue to exist in their present form, and may be altered, including remodeled, reconstructed, or expanded, if such alteration complies with the provisions of this section and all other applicable sections of this chapter.

B. Existing buildings that were legally built or vested prior to the effective date of the ordinance codified in this chapter may be altered only one time within the lifetime of the structure, and:

1. The expansion of the footprint is outside a landslide hazard area or landslide hazard area setback unless required for safety or seismic upgrades;

2. Any expansion of the footprint is located only within a critical area buffer. No expansion of the footprint is allowed within a wetland or fish and wildlife habitat conservation area;

3. Any expansion of the footprint within a critical aquifer recharge area is located outside the aquifer recharge protection area pursuant to BIMC 16.20.100.E.

4. Cantilevers over critical areas are not allowed;

5. The expansion of the footprint at ground level does not exceed 500 square feet;

6. Any expansion of the footprint is used only as indoor living space or to accommodate accessibility;

7. Any expansion of the footprint is no closer to the critical area than the existing footprint; and

8. If a building is harmed or destroyed by more than 50 percent of its square footage, the building must be reconstructed in compliance with the requirements of this chapter.

C. Existing property improvements other than buildings, including driveways, parking areas, yards and landscaped areas, play areas, storage areas, decks less than five feet in height, patios, and similar improvements that were legally established or vested prior to the effective date of the ordinance codified in this chapter may be altered if:

1. Any alteration is in substantially the same location as the original property improvement;

2. Any expansion of the footprint is located only within the required buffer. No expansion of the footprint is allowed within the critical area itself and cantilevers over critical areas are not allowed;

3. Any expansion of the footprint is no closer to the critical area than the existing footprint; and

4. Any expansion of the footprint within a critical aquifer recharge area is located outside the aquifer recharge protection area pursuant to BIMC 16.20.100.E.

D. Existing electric transmission and distribution lines that traverse or are directly located in wetlands may be altered, maintained and upgraded in ways that do not meet the precise terms of an exempt activity in BIMC 16.20.040 if:

1. The applicant demonstrates that the proposed alterations, maintenance or upgrades provide the least impact to regulated wetlands necessary in order to provide utility services to the public;

2. The alteration, maintenance or upgrade is the minimum necessary and there is no practicable alternative location or construction activity with less adverse impact on the functions and values of the critical area;

3. Replaced poles shall not be moved more than 20 feet from the original location. New poles added as part of an upgrade must be installed within a 20-foot distance of the existing distribution and/or transmission line infrastructure.

a. If the applicant can demonstrate a lower overall impact to the wetland, new or replaced poles may be located farther than 20 feet from existing infrastructure with a minor conditional use permit;

4. Proposed vegetation removal is unavoidable and is demonstrated to be a present or future danger to the transmission or distribution lines. Vegetation removal shall follow the procedure under BIMC 16.20.090.C. Any area of disturbance shall be revegetated with appropriate native vegetation at not less than preconstruction functions and values or greater, upon completion of construction or within a timeframe proposed to and approved by the director. The director retains the right to require additional mitigation if the proposed revegetation does not sufficiently protect the functions and values of the wetland and its buffer. The utility shall ensure that such vegetation survives or is replanted if the replanting fails within a minimum of five years;

5. The alteration, maintenance or upgrade does not pose an unreasonable threat to the public health, safety, or welfare on or off the development proposal site; and

6. The alteration, maintenance or upgrade avoids and minimizes the impact on critical areas in accordance with required mitigation sequencing under BIMC 16.20.030 and demonstrates no net loss as defined in BIMC 16.20.190.A.59, and is consistent with best available science.

7. The director may require additional mitigation measures if they are deemed necessary in accordance with the required mitigation sequencing described in BIMC 16.20.030.

E. Buffer modifications pursuant to BIMC 16.20.110 and 16.20.140 shall not be granted for existing development.

F. Alterations permitted by this section must comply with other applicable city code or land use review requirements and require submittal of a critical areas permit application in accordance with the permit and review procedures required for the affected critical area(s). (Ord. 2024-04 § 2, 2024; Ord. 2018-01 § 2 (Exh. A), 2018)