HomeMy WebLinkAbout1997.02.03 - Preliminary 100-Year Flood Plainf trE -ts J-I>J ( 11"'.+>r.aL
IPolsfb Englneedng ond
206 South Uncoln Street, Sulte 2ol
Porf Angeles, Woshlngton 98i162
(360) d52-5393 FA)( (360) 457-9319
lnc.
Febnrary 3,,1997
City of Port Townsend
Deparfinent of Public Works
5210 Kuhn Sheet
Port Townsen4 WA 9836t
ATTN: Mr. Doug Mason
RE; Basins 6 &7
heliininary I 00-Year Flood Plains
DcarDoug,
Plcase i'rnd enclosed the p,reliminary flood plain exhibits for Basins 6 &7, The present intent of
the exhibit is to show the approximate extent of flooding and to provide a basis for
understanding the relationship between area ponds as both wetlands and drainage stnrctures. The
ponds act as temporary storage devices to hold runoffuntil it can *L^ absorbed into the soil.
Additionally, the ponds are presumcd to be low quality, seasonal wetlands. While no functional
determination has been made, it is assumed ihal when a determination is made, the ponds will
have high scores in Flood/Storm Water Control and low scores for Flabitat Value. The firnction
scores will have a significant impact o how the ponds wrll be utilized.
The flood plain reflects the basin when fully developed at the current zoningdensity. No
allowances were made for the reduced density due to current development (4 to 6 units per aore)
or tbr future infiltration in areas of SCS Class A soils. I have made no attempt to maximize the
use of the ponds through grading changes, or to calculate the possibility of using either pond tbr
storm water mitigation for offsirc areas. While these changes should be considered" they were
beyond the scope of work for this analysis.
Please note that a nurnber of existing residences are within the proposed flood plsins as well as a
number of lots which couldbe developed.
Sincerely
Civil Engineer
cc: JN95103
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