Building Review



Public Works Storm Water
Review No:1 Application with stormwater management report and civil plan sheets by Roper Engineering dated January 24, 2019 has been received. Please address the following: 1) Provide an updated stormwater management report that addressed the following: a) Section C.2: Describe on the project plans and in the recorded maintenance agreement what pollutant generating activities are/will be conducted on the site and what permanent and/or operation source control measures will be implemented to prevent the discharge of pollutants, as applicable. b) Section C.3.a: Please provide information on the project design and provide analysis consistent with this section. Show how the mitigation facilities have been designed to take all areas draining to them into account in terms of sizing and bypass. - Provide analysis demonstrating the pond will drain within 48 hours. Include a subdrain at the top of the rock storage section if needed. - Provide final analysis showing how the actual drainage areas have been accounted for when sizing the biofiltration, detention and flow control facilities. c) Section C.3.c: Please include a narrative introduction to the concept of stormwater management on the site in the Stormwater Management Report that addresses each of the Site Design and Runoff Reduction measures called for in this section. 2) This site may require coverage under the State’s General Stormwater Industrial Permit. Parcel and contact information will be forwarded to the Regional Water Quality Control Board regarding potential General Industrial Permit coverage. 3) Provide final stormwater management plans that are consistent with the final analysis and which include construction details and specification for stormwater mitigations, stormwater routing, flow control facilities, safe overflow provisions, methods for minimizing clogging and maintenance, etc.. - Provide additional grading and spot elevations where the existing and proposed paved areas meet west of the existing storage shed demonstrating how all runoff from the unpermitted paved areas will be routed to the proposed pond prior to discharge to the existing channel. - Plans shall be updated to provide minimum dimensions of the proposed pond ensuring mitigation volumes are provided. - Update detail for the pond to include notes for no compaction or liners of the pond consistent with Section C.3.b.iii of the CDC. 4) If the applicant chooses not to provide the downstream assessment of the private path, on-site mitigations should be designed to retain and detain runoff to predevelopment levels per the CDC minimum design storms for the unpermitted impervious areas and the applicant/property owner shall provide a hold harmless agreement that assumes all liability/responsibility for not providing and mitigating to the assessment. The draft document shall be provided to County staff and Counsel for review and shall include language that holds the County and Zone 5 harmless. The final document shall be recorded and copy provided to Public Works. 5) Provide a recorded maintenance agreement(s) for proposed mitigation facility(ies) and for the source control measures proposed in compliance with Section C.2 of the CDC as well as the prohibitive signage at the inlets. See Figures SWM25-B in the CDC for examples. The maintenance agreement shall include one attached exhibit that shows the stormwater management facility location/s on the project site along with delineations of the subwatershed area/s draining to each facility. The maintenance agreement shall include a second attached exhibit that lists at a minimum, for each stormwater mitigation: the operation and maintenance requirements, inspection and maintenance intervals, and symptoms of system failure or not functioning as designed. The annual report shall address each item from the attached exhibit and shall include date/s of inspection, name/s of inspector/s, and a detailed list of maintenance and repairs completed. The annual report shall include photos, as necessary, to document operation, maintenance and repairs completed. See Section B Design References, references j (Appendix H) and l (Chapter 6) for examples. See 2^nd Nature’s BMP RAM Protocols for methods for annual inspection, testing and reporting (http://2ndnaturewater.com/documents/BMPRAM_FieldProtocols.pdf) 6) This site receives runoff from upstream offsite areas. Provide a recorded document that acknowledges that the parcel does and will continue to receive upstream runoff, that the property owner is responsible for maintenance of the drainage pathway through the parcel and that the County and Flood Control District are not responsible for the upstream runoff or for maintenance of the drainage pathway. 7) Provide final approval letter from the geotechnical engineer approving of the drainage plans. The letter should refer to dated plans and approve of any design infiltration rate used in mitigation sizing. 8) Zone 5 fees will be assessed on the net increase in permitted impervious area due to the project. This project may be eligible for fee credits for existing impervious areas if documentation is presented demonstrating these areas are permitted or were built prior to 1969. Aerial photos from 1975 available at UCSC online archives may be used for establishing coverage. 9) Inspection of the construction of the drainage related items will be conducted by a Public Works inspector. Please provide the engineer’s estimate for the drainage related items. A 2% deposit for at cost inspection will be assessed. A hold will be placed on the building permit for a preconstruction meeting with the Public Works Inspector. Please call (831) 454-2160 to schedule the meeting at least 48 hours prior to construction. A second hold will be placed for the final construction inspection sign-off.

Public Works Storm Water

Review No:1

Application with stormwater management report and civil plan sheets by Roper Engineering dated January 24, 2019 has been received. Please address the following:

1) Provide an updated stormwater management report that addressed the following:

a) Section C.2: Describe on the project plans and in the recorded maintenance agreement what pollutant generating activities are/will be conducted on the site and what permanent and/or operation source control measures will be implemented to prevent the discharge of pollutants, as applicable.

b) Section C.3.a: Please provide information on the project design and provide analysis consistent with this section. Show how the mitigation facilities have been designed to take all areas draining to them into account in terms of sizing and bypass.

- Provide analysis demonstrating the pond will drain within 48 hours. Include a subdrain at the top of the rock storage section if needed.

- Provide final analysis showing how the actual drainage areas have been accounted for when sizing the biofiltration, detention and flow control facilities.

c) Section C.3.c: Please include a narrative introduction to the concept of stormwater management on the site in the Stormwater Management Report that addresses each of the Site Design and Runoff Reduction measures called for in this section.

2) This site may require coverage under the State’s General Stormwater Industrial Permit. Parcel and contact information will be forwarded to the Regional Water Quality Control Board regarding potential General Industrial Permit coverage.

3) Provide final stormwater management plans that are consistent with the final analysis and which include construction details and specification for stormwater mitigations, stormwater routing, flow control facilities, safe overflow provisions, methods for minimizing clogging and maintenance, etc..

- Provide additional grading and spot elevations where the existing and proposed paved areas meet west of the existing storage shed demonstrating how all runoff from the unpermitted paved areas will be routed to the proposed pond prior to discharge to the existing channel.

- Plans shall be updated to provide minimum dimensions of the proposed pond ensuring mitigation volumes are provided.

- Update detail for the pond to include notes for no compaction or liners of the pond consistent with Section C.3.b.iii of the CDC.

4) If the applicant chooses not to provide the downstream assessment of the private path, on-site mitigations should be designed to retain and detain runoff to predevelopment levels per the CDC minimum design storms for the unpermitted impervious areas and the applicant/property owner shall provide a hold harmless agreement that assumes all liability/responsibility for not providing and mitigating to the assessment. The draft document shall be provided to County staff and Counsel for review and shall include language that holds the County and Zone 5 harmless. The final document shall be recorded and copy provided to Public Works.

5) Provide a recorded maintenance agreement(s) for proposed mitigation facility(ies) and for the source control measures proposed in compliance with Section C.2 of the CDC as well as the prohibitive signage at the inlets. See Figures SWM25-B in the CDC for examples. The maintenance agreement shall include one attached exhibit that shows the stormwater management facility location/s on the project site along with delineations of the subwatershed area/s draining to each facility. The maintenance agreement shall include a second attached exhibit that lists at a minimum, for each stormwater mitigation: the operation and maintenance requirements, inspection and maintenance intervals, and symptoms of system failure or not functioning as designed. The annual report shall address each item from the attached exhibit and shall include date/s of inspection, name/s of inspector/s, and a detailed list of maintenance and repairs completed. The annual report shall include photos, as necessary, to document operation, maintenance and repairs completed. See Section B Design References, references j (Appendix H) and l (Chapter 6) for examples. See 2^nd Nature’s BMP RAM Protocols for methods for annual inspection, testing and reporting (http://2ndnaturewater.com/documents/BMPRAM_FieldProtocols.pdf)

6) This site receives runoff from upstream offsite areas. Provide a recorded document that acknowledges that the parcel does and will continue to receive upstream runoff, that the property owner is responsible for maintenance of the drainage pathway through the parcel and that the County and Flood Control District are not responsible for the upstream runoff or for maintenance of the drainage pathway.

7) Provide final approval letter from the geotechnical engineer approving of the drainage plans. The letter should refer to dated plans and approve of any design infiltration rate used in mitigation sizing.

8) Zone 5 fees will be assessed on the net increase in permitted impervious area due to the project. This project may be eligible for fee credits for existing impervious areas if documentation is presented demonstrating these areas are permitted or were built prior to 1969. Aerial photos from 1975 available at UCSC online archives may be used for establishing coverage.

9) Inspection of the construction of the drainage related items will be conducted by a Public Works inspector. Please provide the engineer’s estimate for the drainage related items. A 2% deposit for at cost inspection will be assessed. A hold will be placed on the building permit for a preconstruction meeting with the Public Works Inspector. Please call (831) 454-2160 to schedule the meeting at least 48 hours prior to construction. A second hold will be placed for the final construction inspection sign-off.

CDI - Application Status