Memorandum 15-100 Impervious Coverage in Bridge Creek Watershed District

SUBJECT: RECOMMENDATION FROM HOMER ADVISORY PLANNING COMMISSION REGARDING THE PROPOSED AMENDMENT TO HCC 21.40.070, REQUIREMENTS, REGARDING STANDARDS FOR IMPERVIOUS COVERAGE IN THE BRIDGE CREEK WATERSHED PROTECTION DISTRICT.

For approximately one year the Planning Commission has discussed the Bridge Creek Watershed Protection District (BCWPD). The commission considered increasing the amount of impervious coverage from the current allowance. After the testimony received from two public hearings, where every property owner in the watershed was sent direct notification, the Commission decided against an increase. The Planning Commission’s draft ordinance does allows development proposals in the district (those eligible to exceed 4.2% impervious coverage) to be completed with less delay and clarifies a more uniform procedure for impervious surface mitigation.

Non-ordinance recommendation for the BCWPD

Platting fees be waved when vacating lines to increase lot sizes.
Increase City efforts to purchase one property a year.
Examine ditch cleaning policies and work with DOT on Skyline Drive maintenance including minimizing road ditch clearing to minimize possible negative effects to the watershed.
Ask Public Works not to use calcium chloride for dust control.

Current Procedure

All lots in the BCWPD are allowed up to 4.2% of impervious coverage, lots smaller than 2.5 acres are allowed to provide mitigation for review at the Planning Commission for up to 6.4% of impervious coverage. The standards for mitigation are not defined in code. Taking the plan to the Commission incurs additional time compared to standard permits that may be issued by the Planning Department. Not having defined standards for the calculation of mitigation leads to staff suggesting the measures which then need to be ‘sold’ to the Commission. There is little consistency between mitigation plans or outcomes and this creates a lot of uncertainty for developers.

Proposed Amendments

1.) The Commission recommends that the City Planner review and approve mitigation plans without having to go before the Commission.

2.) Reseeding is prescribed by a date specific so that vegetation has an opportunity to be established before the winter and the opportunity for runoff is decreased.

3.) Standards are proposed for design of the mitigation plan. The storm water event that is defined as the same that is required elsewhere in code, rainfall at a rate of 1.5 inches per hour for 3 hours. While common methods of approved retention forms are listed, others may be approved.

4.) The calculation of impervious surface for the purpose of mitigation is based on professional engineering standards. Prescribed calculations for typical driveways, walkways, and structures are those an engineer uses to create an appropriate mitigation plan. Other methods still have an option for other calculations in case someone wanted to install a ‘green roof’ or other non-typical measure.

Eliminated is the subjective nature of partially excluding driveways without having any specific expectations. Currently, the commission may decide to grant someone some sort of exclusion, but they have no standards in code for this provision. This leads to inconsistency among applicants and can alter the carefully thought out provisions for impervious throughout the district.

The proposed amendment was a subject on 12 Planning Commission meetings. The meetings of the October 15th, November 5th and April 15th were public hearings where the entire Bridge Creek Watershed Protection District was sent a notice. While testimony was varied, a great deal was against creating the opportunity for additional impervious coverage. Allowing the Planner to process permits was universally accepted.

Planning staff review of the zoning code amendment as required by HCC 21.95.040.

21.95.040 Planning Department review of code amendment. The Planning Department shall evaluate each amendment to this title that is initiated in accordance with HCC 21.95.010 and qualified under HCC 21.95.030, and may recommend approval of the amendment only if it finds that the amendment:

a. Is consistent with the comprehensive plan and will further specific goals and objectives of the plan.

Discussion: Comprehensive Plan Chapter 4, Goal 2: “Maintain the quality of Homer’s natural environment and scenic beauty.” A strategy stated to accomplish this goal includes “recommend that appropriate standards be adopted so that where development does occur it is designed to respect environmental functions and characteristics.” Examples giving include “site development policies for drainage, vegetation, and grading.” This amendment is directly correlated toward accomplishing this goal.

Staff response: This amendment is consistent with the Comprehensive Plan.

b. Will be reasonable to implement and enforce.

Staff response: This code amendment will be reasonable to implement and enforce. Standards for mitigation calculation are more certain than current policy.

c. Will promote the present and future public health, safety and welfare.

Staff response: The public health, safety and welfare is promoted in the creation of targeted standards to help mitigate potential negative impacts on the Bridge Creek Reservoir.

d. Is consistent with the intent and wording of the other provisions of this title.

Staff response: This amendment is consistent with the intent and wording of other provisions of this title. The amendments have been reviewed by the City Attorney and are deemed consistent with the intent and wording of the other provision of this title.

21.95.010 Initiating a code amendment.

Staff response: The Planning Commission initiated the code amendment, per 21.95.010(b).

21.95.030 Restriction on repeating failed amendment proposals.

Staff response: This section of code is found to be not applicable.

Att.

Proposed draft ordinance
Staff Reports with attachments
Excerpts of Planning Commission minutes

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