Building Review



Public Works Storm Water
Review No:1 Previous miscellaneous comments have not been addressed completely. 1. The drainage calculations dated August 25, 2008 need to be revised. The pervious concrete area is draining directly into the detention volume therefore should be included in the detention volume sizing. 2. According to section D on sheet C4 the gravel sub-base below the pervious surfacing will be sloped towards the sub-drain pipe. The detention volume and percolation rate calculations do not take into account the sloping gravel sub-base. Please revise. 3. The percolation rate calculations do not include an adjustment factor for the effective surface area based on variability within the soil profile and bottom sedimentation. Please include an adjustment factor or provide justification for not including an adjustment factor in the calculations. 4. Please make clear on the plans the depth of gravel below the proposed sub-drain pipe. Demonstrate that the required detention/retention volume is provided below the proposed sub-drain pipe. 5. The inlets in the pervious concrete/paver areas should be elevated to allow all runoff to percolate through the pervious surfacing as indicated in the calculations. 6. If permeable pavers are chosen please provide manufactures specifications and analysis demonstrating that the infiltration rates through the pavers are comparable to infiltration rates through pervious concrete. 7. The ends of any perforated line shall be provided with a minimum 6 inch cleanout and inspection access riser reaching the ground surface. 8. Provide calculations demonstrating that the proposed rock rip rap energy dissipaters are adequately sized. Show that the velocity downstream of the proposed energy dissipaters meet the permissible velocities for bare soils shown in figure SWM-19b in the Santa Cruz County design criteria based on site specific soils. 9. Submit a review letter from the project geotechnical engineer approving of the final drainage plan including the outfall designs. 10. Please make clear on the plans the locations of the proposed downspouts for each of the 4 buildings and demonstrate how runoff will be directed to the gravel sub-base below the pervious surfacing. 11. Please provide a cross section construction detail of the proposed landscape swales. 12. Please include in the plan set the silt and grease trap detail, figure SWM-12 from the design criteria. 13. Zone 5 fees will be assessed based on the net increase in impervious area due to the project. You may be eligible for fee and impact credits for pre existing impervious areas to be demolished. Please submit documentation of permitted structures, paving, and baserock areas to establish eligibility. Documentations such as assessor’s records, survey records, permit records, dated photos, or other official records that will establish and determine the dates built, the impervious area footprint, or to confirm previous permits received is acceptable. If it is documented that impervious areas were constructed prior to 1969, permit documentation is not needed. 14. Please revise the impervious area calculations on sheet C1 and TS-0 to include the semi-pervious concrete/paver area. Semi-pervious surfaces are assessed at a 50% rate. 15. Site plans shall specify maintenance requirements such as; what needs to be maintained, how often each drainage improvement needs to be maintained, what to look for indicating maintenance is required, and what the maintenance procedures are for each specific drainage improvement. A recorded maintenance agreement is required for the proposed pervious pavement and silt and grease traps. Please contact the County of Santa Cruz Recorder’s office for appropriate recording procedure. The maintenance agreement form can be picked up from the Public Works office or can be found online at: http://www.dpw.co.santa-cruz.ca.us/Storm_Water/FigureSWM25B.pdf 16. Public Works staff will inspect the installation of the drainage related items. Once all other reviewing agencies have approved the building permit plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works. Please submit a construction estimate for all drainage related items. Please deposit 2% of the construction cost or a minimum of $640.00, directly to Public Works. 17. If the project disturbs one acre or more, the applicant is required to obtain an NPDES stormwater permit from the State Water Quality Control Board (SWQCB). Review and inspection of such projects shall complement the stormwater permit requirements. Processing fees will be required, in addition to the SWQCB permit fees, by various County departments, including Public Works, Planning and Environmental Health. The applicant is encouraged to discuss the above comments with the reviewer, Travis Rieber, to avoid unnecessary additional routings. Please call the Dept. of Public Works, Storm Water Management Section, from 8:00 am to 12:00 noon if you have questions. Review No:2 2^nd Review Comments Previous comments have not been addressed completely. 1. The detention system has been redesigned and now includes 3 separate detention ponds under the pervious pavement. Each of the three detention ponds and orifices should be sized separately based on the amount of runoff being direct to each. The pervious pavement areas are draining into and impacting the available detention volume therefore must be included in the detention volume sizing. 2. Please provide calculations demonstrating that each of the detention ponds will completely drain within 48 hours from the cessation of storm runoff. The site soil percolation rate will be needed for these calculations. Please see comment #3 from the first routing when calculating the percolation rates for each of the detention ponds. 3. If permeable pavers are chosen please provide manufactures specifications and analysis demonstrating that the infiltration rates through the pavers are comparable to infiltration rates through pervious concrete. 4. Please make clear on the civil plans the locations of the proposed downspouts for each of the 4 buildings and demonstrate how runoff will be directed to the gravel sub-base below the pervious surfacing. 5. No documentation has been provided to receive credit for existing imperious areas onsite. Zone 5 fees will be assessed based on the net increase in impervious area due to the project. You may be eligible for fee and impact credits for pre existing impervious areas to be demolished. Please submit documentation of permitted structures, paving, and baserock areas to establish eligibility. Documentations such as assessor’s records, survey records, permit records, dated photos, or other official records that will establish and determine the dates built, the impervious area footprint, or to confirm previous permits received is acceptable. If it is documented that impervious areas were constructed prior to 1969, permit documentation is not needed. 6. The recommended BMP maintenance list on sheet C5 needs to include specific maintenance requirements such as; what to look for indicating maintenance is required, and what the maintenance procedures are for each specific drainage improvement. A recorded maintenance agreement is required for the proposed pervious pavement and silt and grease traps. Please contact the County of Santa Cruz Recorder’s office for appropriate recording procedure. The maintenance agreement form can be picked up from the Public Works office or can be found online at: http://www.dpw.co.santa-cruz.ca.us/Storm_Water/FigureSWM25B.pdf 7. Public Works staff will inspect the installation of the drainage related items. Once all other reviewing agencies have approved the building permit plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works. Please submit a construction estimate for all drainage related items. Please deposit 2% of the construction cost or a minimum of $640.00, directly to Public Works. The applicant is encouraged to discuss the above comments with the reviewer, Travis Rieber, to avoid unnecessary additional routings. Please call the Dept. of Public Works, Storm Water Management Section, from 8:00 am to 12:00 noon if you have questions. Review No:3 3^RD Review Comments Plans are tentatively approved pending signoff by the Director of Public Works. Once all other reviewing agencies have approved the civil engineering plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works.

Public Works Storm Water

Review No:1

Previous miscellaneous comments have not been addressed completely.

1. The drainage calculations dated August 25, 2008 need to be revised. The pervious concrete area is draining directly into the detention volume therefore should be included in the detention volume sizing.

2. According to section D on sheet C4 the gravel sub-base below the pervious surfacing will be sloped towards the sub-drain pipe. The detention volume and percolation rate calculations do not take into account the sloping gravel sub-base. Please revise.

3. The percolation rate calculations do not include an adjustment factor for the effective surface area based on variability within the soil profile and bottom sedimentation. Please include an adjustment factor or provide justification for not including an adjustment factor in the calculations.

4. Please make clear on the plans the depth of gravel below the proposed sub-drain pipe. Demonstrate that the required detention/retention volume is provided below the proposed sub-drain pipe.

5. The inlets in the pervious concrete/paver areas should be elevated to allow all runoff to percolate through the pervious surfacing as indicated in the calculations.

6. If permeable pavers are chosen please provide manufactures specifications and analysis demonstrating that the infiltration rates through the pavers are comparable to infiltration rates through pervious concrete.

7. The ends of any perforated line shall be provided with a minimum 6 inch cleanout and inspection access riser reaching the ground surface.

8. Provide calculations demonstrating that the proposed rock rip rap energy dissipaters are adequately sized. Show that the velocity downstream of the proposed energy dissipaters meet the permissible velocities for bare soils shown in figure SWM-19b in the Santa Cruz County design criteria based on site specific soils.

9. Submit a review letter from the project geotechnical engineer approving of the final drainage plan including the outfall designs.

10. Please make clear on the plans the locations of the proposed downspouts for each of the 4 buildings and demonstrate how runoff will be directed to the gravel sub-base below the pervious surfacing.

11. Please provide a cross section construction detail of the proposed landscape swales.

12. Please include in the plan set the silt and grease trap detail, figure SWM-12 from the design criteria.

13. Zone 5 fees will be assessed based on the net increase in impervious area due to the project. You may be eligible for fee and impact credits for pre existing impervious areas to be demolished. Please submit documentation of permitted structures, paving, and baserock areas to establish eligibility. Documentations such as assessor’s records, survey records, permit records, dated photos, or other official records that will establish and determine the dates built, the impervious area footprint, or to confirm previous permits received is acceptable. If it is documented that impervious areas were constructed prior to 1969, permit documentation is not needed.

14. Please revise the impervious area calculations on sheet C1 and TS-0 to include the semi-pervious concrete/paver area. Semi-pervious surfaces are assessed at a 50% rate.

15. Site plans shall specify maintenance requirements such as; what needs to be maintained, how often each drainage improvement needs to be maintained, what to look for indicating maintenance is required, and what the maintenance procedures are for each specific drainage improvement. A recorded maintenance agreement is required for the proposed pervious pavement and silt and grease traps. Please contact the County of Santa Cruz Recorder’s office for appropriate recording procedure. The maintenance agreement form can be picked up from the Public Works office or can be found online at:

http://www.dpw.co.santa-cruz.ca.us/Storm_Water/FigureSWM25B.pdf

16. Public Works staff will inspect the installation of the drainage related items. Once all other reviewing agencies have approved the building permit plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works. Please submit a construction estimate for all drainage related items. Please deposit 2% of the construction cost or a minimum of $640.00, directly to Public Works.

17. If the project disturbs one acre or more, the applicant is required to obtain an NPDES stormwater permit from the State Water Quality Control Board (SWQCB). Review and inspection of such projects shall complement the stormwater permit requirements. Processing fees will be required, in addition to the SWQCB permit fees, by various County departments, including Public Works, Planning and Environmental Health.

The applicant is encouraged to discuss the above comments with the reviewer, Travis Rieber, to avoid unnecessary additional routings. Please call the Dept. of Public Works, Storm Water Management Section, from 8:00 am to 12:00 noon if you have questions.

Review No:2

2^nd Review Comments

Previous comments have not been addressed completely.

1. The detention system has been redesigned and now includes 3 separate detention ponds under the pervious pavement. Each of the three detention ponds and orifices should be sized separately based on the amount of runoff being direct to each. The pervious pavement areas are draining into and impacting the available detention volume therefore must be included in the detention volume sizing.

2. Please provide calculations demonstrating that each of the detention ponds will completely drain within 48 hours from the cessation of storm runoff. The site soil percolation rate will be needed for these calculations. Please see comment #3 from the first routing when calculating the percolation rates for each of the detention ponds.

3. If permeable pavers are chosen please provide manufactures specifications and analysis demonstrating that the infiltration rates through the pavers are comparable to infiltration rates through pervious concrete.

4. Please make clear on the civil plans the locations of the proposed downspouts for each of the 4 buildings and demonstrate how runoff will be directed to the gravel sub-base below the pervious surfacing.

5. No documentation has been provided to receive credit for existing imperious areas onsite. Zone 5 fees will be assessed based on the net increase in impervious area due to the project. You may be eligible for fee and impact credits for pre existing impervious areas to be demolished. Please submit documentation of permitted structures, paving, and baserock areas to establish eligibility. Documentations such as assessor’s records, survey records, permit records, dated photos, or other official records that will establish and determine the dates built, the impervious area footprint, or to confirm previous permits received is acceptable. If it is documented that impervious areas were constructed prior to 1969, permit documentation is not needed.

6. The recommended BMP maintenance list on sheet C5 needs to include specific maintenance requirements such as; what to look for indicating maintenance is required, and what the maintenance procedures are for each specific drainage improvement. A recorded maintenance agreement is required for the proposed pervious pavement and silt and grease traps. Please contact the County of Santa Cruz Recorder’s office for appropriate recording procedure. The maintenance agreement form can be picked up from the Public Works office or can be found online at:

http://www.dpw.co.santa-cruz.ca.us/Storm_Water/FigureSWM25B.pdf

7. Public Works staff will inspect the installation of the drainage related items. Once all other reviewing agencies have approved the building permit plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works. Please submit a construction estimate for all drainage related items. Please deposit 2% of the construction cost or a minimum of $640.00, directly to Public Works.

Review No:3

3^RD Review Comments

Plans are tentatively approved pending signoff by the Director of Public Works. Once all other reviewing agencies have approved the civil engineering plans, please submit a copy of wet signed civil plans with the DPW signature block and a vicinity map on the first sheet directly to Public Works.

CDI - Application Status