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Mr. Mike Boulay <br />Diviriom ojMimeratr amd Geohgy <br />September 30, 2004 <br />Page 2 <br />S. noire and update Appendix C of Section 7-12 to include design flow and riving information for all culverts shown <br />on Exhibit 7- 19. The new culvert designs rubmitted with this revision for Culverts 19A, 24A, and 45A an <br />acceptable <br />Response: <br />1. Permanent culverts have been listed on pg 7-12-1 <br />2. All permanent culverts aze shown on Exhibit 7-19, Postminiug Drainage Control <br />3. Appendix C has been updated to include hydrologic and hydraulic calculations for the <br />permanent culverts <br />4. The nomograph has been removed from Appendix C- SEDCAD designs fox the permanent <br />culverts have been copied from Appendix 12-2, Culvert Calculations, and are attached for <br />insertion into Appendix C of Appendix 7-1$Post-Muting Drainage Control. <br />5. Culvert Desimts (pg 7-12-Sa) section has been updated. <br />6. A discrepancy war noted between the summary sheet for the channel design (page 7-12-40) and the channel profile <br />(Exhibit 7-20 Sheet 1 of 23) for channel PM-1 Lauver. The depth offlow for tfie vegetated portion of the channel it <br />not conrirtent behveen the channel profile and the channel design rummary sheet. The conrtrrrction depth should <br />alwayr be taken from the capacity analysis, which in this care it retardance clam B w/freeboard (2.49 ft.). For a <br />discussion of capacity analysis versus stability analysis, p/eare refer to page 99 of the SEDCAD 4 Design Manual <br />Thin it correctly shown on theprofzle, but the summary sheet rbou/d be revived Thu inconsistency war noted for other <br />channel rummary sheets and profiler including those for PM-9, PM-12, and PM-15. Please ensure consistency <br />between the rummary sheets and channel profiler and alwayr take the construction depth from the capacity analysis. <br />Response: The Channels Summary sheet has been revised. <br />The original SEDCAD demonrtrotion forPM-12 it contained ou page 7-12-27 of the permit document. Bared on <br />this demonstration, the original channel design utilised a peak discharge of 8 cfr and indicated a vegetater~ V- <br />rhaped channel Channel PM-12 bar been recently reconstructed as a riprap channel due to the erosive mnditivns <br />noted in the vegetated channel No new SEDCAD demonstration war rubmitted far PM-12 However a new <br />channel design war rubmitted indicating peak discharge of 1.0 cfr, which a inconrirtent nath the approved <br />SEDCAD run. This it the design drscharge for new channel segment PM-12A. The new rammary sheet <br />accompanying the channel design inda'cater veg. andgravel will be utik'Zed in the channel. Please correct the channel <br />design, rummary sheet, and channel profile to indicate the correct peak discharge for PM-12. <br />Response: Updated SEDCAD demonstrations (hydrology and hydraulic) for SIIPM-12 aze included <br />in this package. <br />8. The channel design and profile rubmitted for PM-17 utilize incorrect design flow and slope valuer. The peak <br />discharge from the existing SEDCAD run it 3.4 cfr and the nape ar indicated on the previous profile should be 2- <br />13%. Please revise the channel design and profile far PM-17 accordingly. <br />Response: An updated SEDCAD run fox PM-17 has been included as part of the PM-12 SEDCAD <br />demonstration. This demonstration shows that the peak discharge for PM-17 is 0.25 cfs and the <br />slopes indicated on the channel profile presented on the previously submitted profile aze correct <br />