HomeMy Public PortalAboutdowners comments.pdfLisa Schaaf
From: Downer Davis <dkdbus@gmail.com>
Sent: Friday, August 02, 2019 10:59 AM
To: George Shaw
Cc: Lisa Schaaf
Subject: Re: FW: PN 19-1000 - TIMA Expansion SWMR Submittal
I offer the following comments on the Engineer's Thursday, August 01, 2019 5:17
PM submital you forwarded to me Fri, Aug 2, 2019 at 8:09 AM.
Drainage Report:
• It is anticipated that no drainage will leave the site under these design
conditions. I'm not sure how this statement can be correct. Additionally, it's not
necessary as runoff is definitely leaving the site
now. The volume of run-
off generated from the roof top will be approximately 114 -cubic feet using a 25 -
year 24-hour storm
event with an intensity of 0.33 -inches (from GSMM Volume 2 for Savannah) "Run-
off" means just that, "run" "off" of the area under consideration. The volume of
storage provided by the 6" gravel base beneath the building is approximately
870.4 -
cubic feet using a porosity factor of 0.4 for gravel. The Blue Book with the CSS,
only allow 0.32 or 0.3 (immaterial and I'm not looking it up at this
time). Additionally, the ground had comparable storage that has not been
considered. Since the soils are Group A (Attachment C - Web Soil
Survey), it
assumed that the infiltration rate is 6"/hour or 2,176 -cubic feet per hour. This
means the infiltration practice will drain in
approximately 30 -minutes or less. The site will effectively accommodate the 25 -
year 24-hour storm event onsite without
contributing to any conditions downstream of the site. Great point, since the peak
hour is around 3.23 inches and total 24-hour rainfall is approximately 8 inches per
hour.
• Energy dissipation at the discharge from the downspouts..
• Since we're on the Atlantic Ocean, if the reference to the Pacific can be removed,
that'd greatly reduce the likelihood of some unnecessary conversation involving all
in the email distribution.
• The drainage area needs to be clearly shown in the report. I can follow where it is
from the description and the plans, but an exhibit needs to be added or the topo
marked up.
Construction Civil Plans:
1
" T h e s a m e s y m b o l i s u s e d f o r t h e p r o p o s e d c o n c r e t e p a d a n d t h e a r e a t o t h e n o r t h
l a b e l e d c r u s h e r r u n . A s t h e E n g i n e e r c o n s i d e r e d b o t h i m p e r v i o u s , i t d o e s n ' t a f f e c t
m y c o n c u r r e n c e . H o w e v e r , f r o m a n A D A p e r s p e c t i v e a n d t h e I i k e l y h o o d , i t ' l l b e
p a v e d , I r e c o m m e n d t h e E n g i n e e r c h a n g e t h e h a t c h i n g s y m b o l t o b e d i f f e r e n t f o r
t h e c r u s h e r r u n , s t a t e i t t o b e a n e i t h e r / o r , c h a n g e i t t o c o n c r e t e , e t c . . . . a t h i s
o p t i o n .
" T h e g r a d i n g p l a n s h o w s r u n o f f f r o m t h e a r e a s n o t u n d e r r o o f t o c o n t i n u e t h e p r e
d e v e l o p m e n t p a t t e r n o n t o T o t s t o t h e n o r t h a n d e a s t . I t t h a t i s t h e c a s e a n d t h o s e
p r o p e r t i e s a r e o w n e d b y t h e C h u r c h , p l e a s e c l a r i f y . A s I u n d e r s t a n d t h e s c h o o l
h a s n o a g r e e m e n t f o r t h o s e a d j a c e n t p r o p e r t i e s , c o n c u r r e n c e i s n e e d e d f r o m t h e
C h u r c h f o r t h i s r u n o f f .
" T h e d o w n s p o u t l o c a t i o n s o n t h e e a s t s i d e o f t h e b u i l d i n g n e e d t o b e s h o w n a n d
w i t h t h e d i s c h a r g e f l o w p a t h s h o w n t o c o n f i r m f l o w b e n e a t h t h e b u i l d i n g .
" " G r a v e l " b e n e a t h t h e b u i l d i n g n e e d s t o b e c l a r i f i e d a s # 5 7 o r
w h a t e v e r . C l a r i f i c a t i o n i s n e e d e d t h a t m a i n t a i n i n g t h e p r e d e v e l o p m e n t s u r f a c e
t o p o g r a p h y w i l l r e q u i r e t h e r e m o v a l o f s o i l p r i o r t o p l a c e m e n t o f t h e s t o n e .
" T h e r e p o r t s t a t e s , " . . . i i m p e r v i o u s a r e a w i l l b e r e d u c e d i n t h e e x i s t i n g p a r k i n g a r e a s
a l o n g L o v e l l A v e n u e t o b a l a n c e
o u t t h e n e t r e s u l t s . T h e t a b l e b e l o w r e f l e c t s t h i s c h a n g e . " T h e p l a n s n e e d t o
r e f l e c t t h i s .
" P r o p o s e d u n p a v e d p a r k i n g s p a c e s n o t e d o n t h e p l a n s a r e
u n a c c e p t a b l e . S t a b i l i z a t i o n i s r e q u i r e d . I f t h e s e a r e t h e a r e a s o f r e d u c e d
i m p e r v i o u s a r e a s , t h e m e t h o d o f a c c o m p l i s h i n g t h i s n e e d s t o b e n o t e d . W i l l t h e y
b e p e r m e a b l e s t o n e ( n o t c r u s h e r r u n ) , p e r m e a b l e b r i c k p a v e r s , o r 7 E a r t h ,
g r a s s , e t c . . . i s n o t c o m p l i a n t w i t h g o v e r n i n g e r o s i o n c o n t r o l a n d s t a b i l i z a t i o n
r e q u i r e m e n t s .
T h e E n g i n e e r ' s i n t e n d e d d e s i g n r e f l e c t s t h a t . . . .
" t h e i m p e r v i o u s a r e a a n d , t h u s , t h e r u n o f f c o e f f i c i e n t w i l l b e r e d u c e d .
" t h e t r a v e l t i m e o f c o n c e n t r a t i o n a n d t o t a l t i m e o f r u n o f f l e a v i n g t h e s i t e w i l l n o t b e
r e d u c e d . ( I t ' s l i k e l y i t c a n b e s h o w n t o b e i n c r e a s e d i f n e c e s s a r y . )
E a c h o f t h e s e d e s i g n f e a t u r e s , i n d e p e n d e n t l y , s h o w t h a t r u n o f f w i l l n o t b e
i n c r e a s e d . P r e a n d p o s t r u n o f f c a l c u l a t i o n s c a n b e s h o w n d e m o n s t r a t i n g n o i n c r e a s e d
r u n o f f . T h e p l a n s n e e d c l a r i f i c a t i o n . I ' m n o t r e c o m m e n d i n g a n y c h a n g e s i n d e s i g n
m e t h o d . I u n d e r s t a n d t h e d e s i g n a n d I t r u l y w a n t t o c o n c u r . W h e n t h e r e p o r t i s
c l a r i f i e d a n d t h e p l a n s a r e r e v i s e d t o a d e q u a t e l y r e f l e c t s i t e c o n s t r u c t i o n r e q u i r e m e n t s , I
c a n c o n c u r w i t h t h i s d r a i n a g e p l a n .
D o w n e r
O n F r i , A u g 2 , 2 0 1 9 a t 8 : 0 9 A M G e o r g e S h a w < g s h a w @ c i t y o f t y b e e . o r g > w r o t e :
D o w n e r ,
2
Please review and comment asap.
George
From: Jason Ball <jason@ballmaritime.com>
Sent: Thursday, August 01, 2019 5:17 PM
To: George Shaw <gshaw@cityoftybee.org>
Cc: Perb Fortner <perbfortner@hotmail.com>; 'Carolyn Jurick' <CKjurick@comcast.net>; Brian Allen
<brian@ballmaritime.com>
Subject: PN 19-1000 - TIMA Expansion SWMR Submittal
George,
Attached is our re -submittal with the requested information. Please review and let us know if you
have any questions.
Regards,
Jason
Jason P. Ball, PE, D.PE, D.NE
Mobile (912) 662.2914
jason(a,ballmaritime.com
Ball Maritime Group
4 Cedar View Court
Savannah, GA 31410
Visit us at: ballmaritime.com
This message, including any attachments, may include privileged, confidential and/or inside information. Any distribution or use of this
communication by anyone other than the intended recipient is strictly prohibited and may be unlawful. If you are not the intended
recipient, please notify the sender by replying to this message and then delete it from your system.
3