Floodplain.pdf

November 23, 2021

Katie Gibble Ada County Highway District 1301 N Orchard Street Boise, ID 83706 kgibble@achdidaho.org

Re: CFH21-00150 & CFH21-00151 / 200 E. Mallard Dr. / Floodplain & River System Permit

Dear Katie Gibble:

Your application for an administrative level Floodplain & River System Permit has been reviewed per Section 11-08-03, 11-03-04(19) and 11-05-06.1 of the Boise City Zoning Ordinance. Based upon the plans and application information submitted to the Boise City Planning and Development Service Department date stamped received on October 21 and 22, 2021, the application is approved.

SUMMARY

The applicant is requesting a floodplain and river system permit for proposed bridge and roadway improvements over Loggers Creek and its associated riparian setback. It is also located outside the required setbacks along the Boise River. The Ada County Highway District (ACHD) is proposing to replace the existing Mallard Drive bridge over Loggers Creek. The new bridge will include a larger box culvert design to convey the Logger Creek flows. The bridge replacement and roadway improvements are located within regulatory floodplain (AE zone).

The Planning Director can approve Boise River System permits that meet specific criteria.

The proposal meets these criteria as the project does not affect more than 100 lineal feet of river bottom or bank, nor more than one-half acre of Class A or B lands. The riparian area along Loggers Creek is considered Class A Lands. However, public infrastructure (i.e. right-of-way and bridges) are allowed within Class A lands.

These improvements must be constructed in strict conformance with the most recent Boise City Floodplain and River System Ordinance (B.C.C. 11-08) and Title 44 of the Code of Federal Regulations. Detailed conditions of approval are required by Public Works, as outlined in the memo dated November 10, 2021 and these conditions are listed below.

mailto:kgibble@achdidaho.org

Page 2 of 6 | Administrative Approval | CFH21-00150 & CFH21-00151 | 200 E. Mallard Dr. | Issued Nov. 23, 2021

• All disturbed areas shall be stabilized and revegetated as soon as possible.

• Permits from the U.S. Army Corp of Engineer and the Idaho State Department of

Water Resource are required for this project. The applicant shall comply with all jurisdictional requirements noted in these permits.

• A LOMR will be required for this project and must be submitted to FEMA within 6 months after the project is substantially completed or a CLOMR can be submitted at any time before the project is completed. In addition, Title 44 of the Code of Federal Regulation require the submittal of new technical data regarding the changes to the FEMA FRIM panels. Therefore, the applicant is required to submit new data as soon as possible and not later than six months after the information becomes available to the Administrator.

BOISE CITY ZONING ORDINANCE

Flood Hazard Regulations

Section 11-08-03 (2) Standards

A. Uses

1) Except for levees, all new development shall utilize methods and practices that minimize development and prevent the increase in flood damage potential to other properties or other adverse impacts including but not limited to, bank erosion resulting from higher velocities, increased heights of floodwaters, extended flood duration, or alterations that may promote channel blockage.

Finding: The project shall use methods that minimize and prevent the potential for increased flood damage to other properties. A condition of approval requires all disturbed areas caused by construction be stabilized and revegetated as soon as possible.

2) All new development shall utilize materials and utility equipment resistant to flood damage.

Finding: A condition of approval requires the applicant to comply with the jurisdictional requirements of the U.S. Army Corp of Engineers and Idaho State Department of Water Resources as noted in their permits. These permits will verify that these requirements are satisfied.

3) All new construction and substantial improvements to structures shall be anchored to prevent floatation, collapse or lateral movement of the structure.

Finding: All structures associated with the street improvements and bridge replacement shall be anchored to prevent floatation, collapse or lateral movement.

4) All manufactured homes must likewise be anchored to prevent flotation, collapse or lateral movement, and shall be installed using methods and practices that minimize

Page 3 of 6 | Administrative Approval | CFH21-00150 & CFH21-00151 | 200 E. Mallard Dr. | Issued Nov. 23, 2021 flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (Reference FEMA’s “Manufactured Home Installation in Flood hazard Areas” guidebook for additional techniques).

Finding: The application is not for a manufactured home or structure.

5) Drainage practices shall be utilized which minimizes exposure to flood hazards.

Finding: The construction work will utilize Best Management Practices that minimize exposures to flood hazards.

6) Manufacture and/or storage of material which is buoyant, flammable, toxic or explosive is prohibited.

Finding: The project does not include the manufacturing or storage of buoyant, flammable, toxic and explosive materials within the floodplain.

7) River crossings shall be designed to withstand the flows and velocities of the base flood discharge.

Finding: The application does not include a Boise River crossing.

8) All development and structures shall meet or exceed the requirements of the Boise River System Ordinance (Chapter 11-05-06 of this ordinance if applicable).

Finding: A Boise River System Permit (CFH21-00151) is included in this review.

9) Water velocities within the floodway fringe are not significantly increase as to cause adverse effects on the site or to surrounding properties.

Resources as noted in their permits. These permits will verify that these requirements are satisfied.

Finding: A condition of approval requires the applicant to submit new data and information regarding changes to the FEMA FRIM panels to the Administrator.

10) Require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.

Resources as noted in their permits. These permits will verify that these requirements are satisfied.

Page 4 of 6 | Administrative Approval | CFH21-00150 & CFH21-00151 | 200 E. Mallard Dr. | Issued Nov. 23, 2021

River System Section 11-03-04 (19) Approval Criteria

i. The proposed development is in compliance with Applicable Standards for Uses in Class

A, B, or C lands and waters.

Finding: The subject property is considered Class A lands. The proposal is in compliance with the applicable standards for uses in these Class A lands since it is a public infrastructure project (i.e. Mallard Drive bridge replacement).

ii. The proposed development complies with all the policies and standards of the Boise

Comprehensive Plan, the Boise River Plan, the Floodplain Ordinance and the Boise River System Ordinance.

Finding: A condition of approval shall require the compliance with the policies and standards of the Boise Comprehensive Plan, the Boise River Plan, the Floodplain Ordinance and the Boise River System Ordinance. Policy CC2.1(d) of the Comprehensive Plan promotes continued maintenance of streets and right-of-way infrastructure. The proposed project will improve Mallard Drive and replace an existing bridge over Loggers Creek. Policy SHCC 3.4 encourages strategies that maintain flood channel capacity in the Boise River. The new bridge design includes a larger box covert which allows for a greater conveyance of water within Loggers Creek.

Finding: A Floodplain Review Permit (CFH21-00150) is included in this review.

iii. The proposed development included measures designed to insure that natural resources functions and values are preserved or enhanced and maintained.

Finding: Natural Resource functions and values are preserved, enhanced and maintained as the proposal will replace an existing bridge and public infrastructure is allowed within Class A lands. A condition of approval will require the disturbed areas caused by construction shall be stabilized and revegetated as soon as possible with native plants.

iv. The proposed development complies with or shall comply with all local, State and

Federal laws and regulations.

Finding: A condition of approval will require that the applicant comply with all local, state, and federal laws and regulations.

CONDITION OF APPROVAL

1. Construction, use and property development shall be in compliance with plans and specifications on file with the Boise City Planning and Development Services Department date stamped received on October 21 and 22, 2021.

Page 5 of 6 | Administrative Approval | CFH21-00150 & CFH21-00151 | 200 E. Mallard Dr. | Issued Nov. 23, 2021

2. The applicant shall comply will all requirements of Boise City Code Chapter 11-08 (Floodplain Ordinance).

3. Permits for this project are required from the U.S. Army Corp of Engineers and the Idaho

State Department of Water Resources. The project must comply with all jurisdictional requirements noted in the permits. If required, these permits must be supplied to the City prior to issuance of any permits for construction.

4. All disturbed areas caused by construction shall be stabilized and revegetated as soon as possible with native plants.

5. All structures associated with the street improvements and bridge replacement shall be anchored to prevent floatation, collapse or lateral movement.

6. Applicant shall submit a LOMR to FEMA within 6 months after the project is substantially completed or a CLOMR can be submitted at any before the project is completed.

7. The applicant shall submit all new information and data regarding changes to the FEMA FRIM panels to the Administrator as soon as possible, but not later than six months after the data becomes available.

8. Compliance with the policies and standards of the Boise Comprehensive Plan, the Boise

River Plan, the Floodplain Ordinance and the Boise River System Ordinance is required.

9. Comply with the conditions and requirements of the Flood Hazard Regulation

Ordinance, including the requirements of the Boise City Public Works Department letter dated November 10, 2021. For additional information contact Jason Taylor at (208) 608-7171.

May we also take this opportunity to advise you that this approval will not take effect until after the ten (10) day appeal period has lapsed without an appeal being filed. This decision of the Boise City Planning and Development Services Department may be appealed to the Boise City Planning and Zoning Commission within ten (10) days from the date of issuance of this decision. All appeals of this permit must be filed by 5:00 P.M. on December 3, 2021. The appeal must be written, accompanied by the appropriate fee, and submitted to the Boise City Planning Division prior to the deadline set forth above.

Appeal application forms are available at the Boise City Planning and Development Services Department, Second floor, Boise City Hall, 150 North Capitol Boulevard, Boise, Idaho 83701-0500 or online under Applications at: cityofboise.org/pds-appeal.

https://www.cityofboise.org/pds-appeal

Page 6 of 6 | Administrative Approval | CFH21-00150 & CFH21-00151 | 200 E. Mallard Dr. | Issued Nov. 23, 2021

If you have any questions, please contact me at (208) 608-7087.

Sincerely, David Moser Associate Planner, Current Planning & Subdivisions Boise City Planning & Development Services

DM/

cc: Zachary Billingsley / Jacobs Engineering Groups, inc. / zack.billingsley@jacobs.com Fred Fritchman / Southeast Neighborhood Association / Ffritchman@msn.com Jason Taylor / Boise City Public Works/ jtaylor@cityofboise.org

The City of Boise Planning and Development Services Department acknowledges the ancestral, cultural, traditional, and unceded territory of the Shoshone, Bannock, and Northern Paiute people on which our land use and development decisions are made.

mailto:zack.billingsley@jacobs.com mailto:Ffritchman@msn.com