HomeMy WebLinkAboutSDP200600112 Review Comments 2006-11-03 of ALettet
County of Albemarle
Department of Community Development
Memorandum
To: Gerald Gatabu,Current Development planning and zoning review
From: Jonathan Sharp,Current Development engineering review
Date: 3 Nov 2006
Subject: Dominion Office Park,Phase I(SDP200600112)critical slope waiver request
The critical slope waiver request has been reviewed. The engineering analysis of the request follows:
Description of critical slope area and proposed disturbance:
The critical slope area is a wooded area which slopes down to the Rivanna River. The critical slope
areas are located below and directly adjacent to the current building and parking/loading area. The
proposed critical slope disturbance is for additional parking spaces to accommodate a proposed
building expansion. (There is very little undeveloped land on the site which is not critical slopes, so the
proposal is to have the lower parking spaces(7 spaces), landscaping,and stormwater structure(Filterra
and rip-rap)extend into the critical slope area. A retaining will be put in place behind the parking
spaces to minimize grading and disturbance of critical slopes. Guardrail will be provided on the wall to
provide safety. The existing water quality structure(Filterra unit)will be relocated in order to provide
water quality for the entire proposed parking and loading area. The critical slopes disturbed will be
approximately 11%of the critical slopes on site(about 2000 square feet). Figure 1 on page 3 shows the
disturbance of critical slopes.
Areas Acres
Total site 1.09 acres approximately
Critical slopes 0.47 ac 43%of site
Critical slopes disturbed 0.05 ac 11%of critical slopes
Exemptions to critical slopes waivers for driveways, roads and utilities without reasonable
alternative locations:
This disturbance is not exempt.
Compliance with Zoning Ordinance 18-4.2:
"movement of soil and rock"
Proper slope construction,control of drainage, and vegetative stabilization will prevent any movement
of soil. Most or all of the soil movement in areas of critical slope will be fill. It appears that the
retaining wall will need to be constructed by hand,and this is the intent of the applicant.
"excessive stormwater runoff"
Peak stormwater runoff rate will increase slightly(1 cfs or less for the 2 and 10 year storm). This will
not be a problem downstream as the runoff will flow directly into the Rivanna River.
"siltation"
An erosion control plan has not been proposed,as it is generally not required for proposed
developments with less than 10,000 square feet disturbance. It will be difficult to capture any lost
sediment as the area to be constructed in is very steep.However,the amount of disturbance is very
small. One available precaution is to require an erosion and sediment control plan as a condition to the
Page 2 of 7
critical slope waiver. (Disturbing less than 10,000 square feet does not automatically exempt someone
from providing a erosion control plan,the program administrator reserves the right to consider it
exempt or nonexempt.)
"loss of aesthetic resource"
This area will be partly visible from the Rivanna River during the winter;however,there is not much
of a change. There is already a building and loading area there,the only change will be a retaining wall
instead of a natural slope down from the building/loading area of the site. It appears that at a minimum
3 trees will need to be removed in order to put in the proposed development(see pictures 4 and 5 on
page 7)The remainder of the tree buffer between the development and the Rivanna River appear to be
able to remain in place.
"septic effluent"
This project is serviced by public sewer.No septic systems or drainfields are proposed in this project.
Based on the review above,there are no engineering concerns which prohibit the disturbance of the critical
slopes as shown.
Page 3 of 7
Figurel: Dominion Office Park, Phase 1, Major Site Amendment
Request for Critical Slopes Waiver
a
0 ItS0 C 30 Goss ess
1.56
(4)5
p
*"sr allallr mmi WWI arr SNIP 11111111111.1e
erra
Critical Slopes
Development in Critical Slopes
34
Proposed Development
•
Page 4 of 7
Figure 2: Existing Conditions•.
{ , I .... . I
0
'r*, r•1", ...... 4:, '.4*-..., ',...t
it , i‘ \ " '
.
‘ 1‘',V.‘1.\‘ 'A- .
4'141,5), S kt
" 4-'4 V t:.'4.4'' '''''' ' * s'• i*Ii), tt*
*461,,, kl ‘ •C "4 4., .1
kl 'r.ttlt j 1 t A t t
% ' •
N.,,, A 1 ''It‘9% ik ''' •, ....5' ,,,.........
*XiSttng .e, .
6Ck (0, - to be removee evo Xi\ • ' .
i
-..xisting riterre to be Retocot • i i 7
,..•%,,, RapATEO
-,-,"
..., .II. "•• -... ,.., ••
,...,
... ,...., ,
..., ,
,,, ,,,,, • .,, ^,.... '''• 0,:i to be Remove°
-, *--,-, ..•,, ''"" , -,,.„'"---.. „.,,,. • ,,., ...,,
... .,,,,, ,,,. , . xiltintillotooja-berRetecoted
,.„ -... .„ , , '-•,.. --.... ,,,..,, , •
- ,s, -,,, -...,, -• •, ..... --- ...„
...„.
-..,
— ''' --- -- -- ----— ——
., -,.. - .....,
,,,. , --- -.. ..... -•,,...„. ......
0.„ --,...„-" -,•..,--- ,...., '--.. ."`-.- , * ......
•,, ''''.... S" , .., • .... *'., ''''
NN
...°N ....... ....'.. • N, . "..,
Figure 3: Proposed Development:
;
,
I
\.• „ I', AA't \';,,. _,,,,
.....
-- ---_,
-Ts,
1..
- f--------1---- ^
*TN
t elt roposed
)
Patirldlit% 1,-- • / A
• , -....
Area ',Off Atir
Proposed , ''''
---ith,
Buildingi-.‘14"ge al**
.,'.
, ... ..„. \\. - si
Addition f
I
.11# tv-- 1 - — --- — -- _ _.. .
.
....„. ...... -,.. , ,
.... _
__
..... . _ _
Page 5 of 7
Figure 4: Proposed and Existing Overlay
—
,11 ,,
‘ \ 1
, * 1
\I
IA04 „_.1
'i;•04 ` ,,,''
,',..
-A
'''•,4 1 arm 1 ut .,,,, , ,,,,, „„,,,,,,its. ,,, xistng , -
,,-
: ''' ' \. oec6 t '
'efts a vet
\ **
1 r sit
'hvat
INI/11 ifill / '
404,
/4,. Pik tily
(vYtfit's '
, • ..,,,. /
''''Ssht.1,i41444443/44,44.4.
4E40-.. ''''' ''''''''.1,, •""*"* ."''. "..* *- '''. -
" f ----... -,---„. --- - iio ' -- ,- — 5.55 " -
_ . _..
-..-
Picture 1: Existinl Conditionsr
, „ s , r
r5,5 .
4 pl.
4 4 q 'VI IP'
0 Vi d ' 45It Orbit'
.
•*. i ,
.. '1 ‘i 4 .
t 1 i, ,..
i t.
,
,,, ,t i .. 1 At
...
, v
...
AO
".. Arn. # •, .
% — / ' r'''' ' ' # iir
• , • ,0' ' 44 4-l'i ,..1- 'TS,:
, ,,,,,..,, , 4,,,,, •-,,,,-- ,,,- ,,--
, .4 „
44? . - ..ty -, it
,10., -- e4fe. i -
4.f -,.4,-f," 1
Page 6 of 7
Picture 2: Facin. Existin, Filterra and Dumpster
i
fi•
{ { "r
�� '� -`
{
Picture 3: Facin Filterra from behind Dum ster
,�, «� 1 u. "te s> i n.1 w^ ,� `fie J' ' '
.-'i,a,s'=-:',4„t'.‘"'i'
i f,;t1.'
+'�. + ., x f u' ..' 5. ? txd"
,"' t1 a
> e'er .. xw'`i y ? ° R r.7• V t
3- $ Y �^ &ft
$6,.• .1,.., ,,,,9,!..., ... .,,..,,,t-,. .1.,,,t,14 ,;-., .1.
..
, w.„.. ... 2
+ z.,
Yn �. t ,y t
.. — s:.. :,
: . , .... _:.,:„;....„1„. ,
, . .... .... ' '
M
•
Page7of7
Pictures 4&5: Trees to be removed (denoted x's)
tom" �R r '� ���: h . t 3`?i, ,,'�,;a ,,,"u,pi
tic.h . ,,^ t''� , rz rat
Y i t e f•
,•
»
4 6 s,y+ iAp F i
4 l 'NA
"6+
t
5 „ t� t1101011
N.t
.4,*`., ' ..„4
,1,„,,,,, ...
11 ,.
a lU.> y
a� r
eta, '- `° , , 4', ill - , tp$pj s.., .- - c; r� - +.
t 'fit ^1 t + '. .�:' ` • L
•
1, ,.;,,ft..,,,,,^psa ram' 4 �. 4
� ell p k:`,� i.14 `z - Vie^ •..
lk
'a. Vow
" ....y. _ �` " 'fix-