REV04064

• Permit No: M1974086
• IBM Index Class Name: Revision
• Doc Date: 5/6/1980
• Doc Name: REGULAR 112 PERMIT APPLICATION
• Type & Sequence: HR1
• Media Type: D
• Archive: No

' EXHIBIT G (Cont'd)
CONSLUSIONS AND RECO`.IhIEidDATIONS
' A drainage study was prepared for the proposed Ralston Quarry
site in response to the Jefferson County Board of Adjustment Resolu-
tion. The purpose of the investigation was to make observation of
' the existing drainage patterns of the site, calculate the storm run-
off for existing and quarry conditions and to make recommendations
' to minimize the impact of the quarry on the environment. The con-
clusions and recommendations of the foregoing report are:
' a) The existing drainage patterns of the site are such that
storm runoff is basically in a sheet flow form and does not
' enter Long Lake at a concentrated point except for the Swale
on the south. The low intensity, frequent storms produce very
little runoff. In the natural state, no apparent drainage
t problems were observed.
' b) The quarry operation, during the period where little or
no reclamation has taken place, would increase the potential
' storm runoff for the immediate basin tributary to Van Bibber
Creek over historic conditions if a detention pond were not
provided. However, the grading of the quarry will keep
' storm water originating from the quarry area from entering
Long Lake or Ralston Reservoir.
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i
d
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c)
y construct
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t
e storm
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runoff from the quarry site, the peak runoff rates from the
i immediate area will be reduced to values near the historic
rates. The effect of the quarry on the drainage environment
' at Van Bibber Creek will be muted by the detention pond such
that historical and quarry conditions runoff is very nearly
' the same.
d) The quarry site can be graded during excavation and during
' reclamation to properly drain the site and thusly essentially
eliminate the quarry's impact or effect on the drainage
environment.
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