HomeMy WebLinkAboutTR 35337 HYDROLOGY REPORT-020 Spyglass Ranch Tract 35337
Hydrology Study M
5. Main outlet Q used to confirm WSE inside baffle chamber. Q not used in
determining the route rating curve.
Tables 7 summarizes the outlet structure design for Basin #2.
Table 7: Basin #2 Outlet Structure Design Summary
Outlet Structure Openings
Number Invert
orifices Dia. or Invert elev.
or W (in) Area (sf) Elev. above Remark
H (in) (MSL) bottom
(ft)
Stage 1 4 1.5 0.049 1292.00 2.74 At baffle wall
Stage 2 5 12 3.927 1295.85 6.15 At baffle wall
Stage 3 4 8 1.396 1297.18 7.65 At baffle wall
Main Outlet 1.0 48 12.566 1291.20 0 At headwall
Baffle Wall Weir (Stage 4)
Invert Weir
elev. Crest
L (FT) Above Elev.
bottom (MSL)
(ft)
8.0 9.55 1298.75
As already discussed, there is no storm mitigation requirement at this
location since the intended outlet is the Wasson Canyon Basin, an 11MS4"
improved drainage facility owned and operated by RCFCD. However, in this
case, since the goal is to match the approved 100-Year flows in the
existing RCB culvert, the basin outlet is designed to mitigate the 100-Year
storm flows. Table 8 provides a summary of the basin detention
performance.
Table 8: Basin #2 Detention Basin Route Summary
Duration QPK3 (cfs) QPK (cfs) Max Water
QPK (cfs)
UHA into UHA out of Depth in
(hr) basin basin reduction Basin (ft)
1 168.5 72.5 96.0 7.6
Notes:
1. UHA = unit hydrograph for Area "A"
2. Q is 100-Year Strom Frequency.
3. QPK for UHA is calibrated to match the rational method Q.
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