HomeMy WebLinkAboutGrading Plans - 04/09/2020Engineering Analytia, Inc.
January 29, 2020
Rev 3.0 — March 16, 2020
Dan Mogen, EI, CFM
Development Review Engineer
Water Utilities Engineering
City of Fort Collins
700 Wood Street
Fort Collins, CO 80522
Grading/Stormwater Plan Accepted
(Building Permit Released)
Accepted by: Dan Mogen
Date: 06/29/2020
Project No. ll 1066
825 Laporte Avenue
Lot 8 Blk 291
Loomis
B1809199 & B1808930
Note: this plan was accepted after the fact on 4/9/2020
(after the permit was issued) as the original plan did
not indicate all changes indicated in this update.
RE: Drainage Memo — 825 Laporte Ave, Fort Collins, CO
Dear Mr. Mogen,
Engineering Analytics, Inc. (EA) has been retained by Jacob Clyde Construction to provide a
drainage memo to the City of Fort Collins regarding the home addition at 825 Laporte Ave., Fort
Collins, CO.
I visited the site on January 24, 2020, meet with Jacob Eichhorn, and observed the current site
conditions. I reviewed the Site Plan developed by Avis Ward dated 11/27/2019 (Attachment A).
I also reviewed preconstruction photographs and area of concrete flat work prior to construction.
The preconstruction photographs and concrete flatwork prior to construction is provided in
Attachment B. The areas of existing concrete flat work prior to construction are shown in on the
Site Plan provided in Attachment A:
• Back Patio — The area of the back patio was about 260 square feet prior to construction
and consisted of wood decking overlying concrete (See photographs in Appendix B),
which drained to the alley. The current construction of the back patio consists of the
same surface area that also drains to the alley. Thus, there is not change in drainage
associated with the back patio.
• Central Area of the Lot — This area contained about 504 square feet of concrete flat work
in the central area of the lot.
• Driveway — Was about 1,560 square feet of pavement. There is about a 50% reduction
in the area of the existing driveway.
Prior to construction there were three main roof areas that drained water as discussed below:
• Garage — The garage had about 600 square feet of roof with 50% of the roof draining to
east and 50% draining to the west. The downspout on the west side extended to the
property line.
• First Story of the House - No changes were made or proposed to this part of the
residence.
1600 Specht Point Rd. Suite 209 Fort Collins, CO 80525 910.488.3111 www.EngAnalytics.com
P:1111066 Ward Addition 1 Engineer^ing Analytics, Inc.
Drainage Report
Ward Residence
• Second Story of the House - The second story of the existing house has a roof area of
about 936 square feet with 50% of the water draining on the north east corner of the
house and 50°/o of the water draining to the north west corner of the house in the center of
the lot. The downspout at the north east corner of the house discharged to the east
property line.
The current Site Plan indicates that 200 square feet of roof/home is to be added to the existing
residence, thus increasing the impervious area on the lot. At the time of my site visit the addition
was complete.
The proposed construction includes about 1,400 square feet of new concrete on the north, east,
and west side of the house. The location of this concrete is shown in a cloud bubble on the
attached, annotated, site plan. In the area of the new 1,400 square feet of concrete there was 500
square feet of existing concrete. The resulting the net increase in concrete flat wark on the east,
west, and north side of the residence is about 900 square feet.
The following drainage improvements have been made or are recommend to be completed to the
residence, garage or site to mitigate the additional runoff impacts due to the increase in
impervious area in the central area of the lot. The annotated in Attachment A site plan calls out
the areas of drainage improvements.
• Second story roof drainage and addition to the north east will be directed into a drain pipe
which will discharge toward Laporte ave. The drain pipe will discharge to a drain pan or
other means of conveyance at the northeast corner of the garage. The drain pan will
maintain a minimum slope of 1%. To maintain grade the roof runoff will be conveyed in
a solid pipe along the fence rail to the northeast corner of the garage. The drain pan will
discharge to Laport ave. This adjustment to the gutter removes all water flow from the
addition and the second story roof that was discharging toward the lot on the east side.
This results in a reduction of 468 square feet (48'x9.75', half of the second story roofj +
200 square feet (addition) to the central area of the lot.
• A portion of the second story roof drainage to the northwest, which was discharging
directly on the east property line will be directed toward the back of the house to reduce
concentrated flow to the west. Prior to the remodel the roof downspout on the west side
of the house discharged onto the property line. Thus, there is no adverse impact from this
change.
• The concrete from the front door of the house on the west side of the garage will slope to
the front yard at a minimLim slope of 1%. This will result in a reduction of 550 square
feet the central area of the lot.
• The downspout on the east side of the garage will be moved to the northeast corner of the
garage and discharge into a drain pan other means of conveyance to drain to Laporte ave.
with a minimum slope of 1%. The "drain pan" will be elevated as needed to maintain
grade to the street. This is 216 square feet reduction of flow to the eastern lot.
• The downspout on the north west corner of the garage discharges to the front yard. This
results in 225 square feet (30' x 7.5') reduction of flow to the central area of the lot.
March 16, 2020 2 Engin�eering Analytics, Inc.
Drai�iage l�eporl
{f�ard Residence
The new addition and concrete flat work result in an increase in impervious area of about 1,100
square feet. The above improvements result in diverting runoff from approximately 1,659
square feet for flat work and roofs to the front of the lot toward Laporte ave. Thus, resulting in
no addition impact to the adjoining properties to the east, west or alley from the proposed
improvements.
RespectfuIly Submitted,
Engineering Analytics, Inc.
l!(
..
�
�'Jasori - r�w P.�' 4.��28
F'roject Engine :
-�• 3-/�-z
9'•
O'A
�AA��������
A9arch 16, ZO?0 3 Engineerrng Analytics, Inc
ATTACHMENT A
SITE PLAN
Existing House
Total 5Q. FT. = 1,932
Main LVL 5Q. FT. = 1,312
Upper LVL SQ. FT. = 620
Existing Garage 5Q. FT.= 122
Existing O�ce/8onus Rm. SQ. FT. = 418
r cn
3 �
(0
? �
O ��
o .
�
co
�
� 4'-0
r
�
Proposed Rddition/Remodel
SQ. FT. of Addition = 200
Total SQ. FT. of Home = 2,132
Main LVL 5Q. FT. = 1512
Upper LVL SQ. FT. = 620
Garage 5Q. FT. = 286
Govered Porch SQ. FT. = 314
5Q. FT. 5outh (rear lot) of Genter Line = 5Q. FT. South (rear lot) of Genter Line =
Residence = 1,932 Residence = 2132
Office/Bonus Rm = 236 Garage= 49
Garage = 0 Note�Lot drainage to remain Govered Porch=190
substantialiy unchanged. Front Half of Lot SQ. FT. _
Front Half of Lot 5Q. FT. = The 6arage that will be Garage = 23"f
Garage = 122 replacing the existing is the Govered Front Porch = 152
Office/Bonus Rm = 242 same footprint and no
modifications will need to be
made to the existing grading. y.�est L'roperty
`/ \a Line 16�.5' �
I Pi� 5�} i� _ i� �-- Pi� - Pi� Pr� i
�—'f' Breakpoint ,�
� 8 � � �\�\\\\\\��\�\\\ ;. � 130 . 83 9 15/16'
: ` �::
�
0 20' I I �
1
~>65'-6 9/1
stinq Driv�
REAR SE�BALK= 6-�
FRON-5ETBAGe= �5-FT
51�E 5ET0AGK= 5�F-
829 LaPorte Ave
� z
� (D 7
-P 3
,. Pi�'. . -Pi�l � �
0
�
15' �
�; ,� �
��' 7�' � �1 :..�' ►, —> � F, �
—P�_' F�_ �—PI FIL FIL =IL =�.L F;L F�L PiL �'�LI _
� 8reakpoin� ��i �
East Pro erty
l�ine 16l 5' " � z
Garage/Govered porch Elevation of finished floor (FF) is b" above gra�e LaPorte Ave
House addition FF to match existing house FF
�
N
�
D
�
O
�1
�
rn
<
rn
r
D
�
O
A
�
rn
<
rn
0
�m.
o>
S
o �
f w
_wo
od� -
ooa �
��O O
z
�
�
W
H
�
o�
��
<�
DATE:
ii/z�iis
SCALE:
,•-,a
SHEET:
5P
Proposed concrete and drainage improvements
Existing House Proposed AdditionlRemodel
Total 5Q. FT. = 1,932 5Q. FT. of Addition = 200
Main LVL 5Q. FT. = 1,312 Total SQ. FT. of Home = 2,132
Upper LVL SQ. FT. = 620 Main LVL 5Q. FT. = 1512
Upper LVL SQ. FT. = 620
Existing Garage 5Q. FT.= 122 Garage 5Q. PT. = 286
Existing O�ce/8onus Rm. SQ. FT. = 4"f8 Govered Porch 5Q. FT. = 314
5Q. FT. 5outh (rear lot) of Genter Line = 5Q. FT. South (rear lot) of Genter Line =
Residence = 1,932 " �"�'�' "�`.-` ' �'�� ; Residence = 2132
OfficelBonus Rm = 236 SlOpe to c�Yalri "� Garage= 49
Garage = 0 to grass 1% Govered Porch=190
Front Half of Lot 5Q. PT. _ `-� `���'�����������'' Ga agealf23� ot SQ. FT. _
Garage = 122 Govered Front Porch = 152
REARSE�BALK=6-FT
FRON-5ETBAGe= �5-FT
51�E 5ET0AGK= 5�F-
�-,,� �,,-- _
., . r,,�.-
r � � �� ���• , ��-�fJ#�icelF�an�� Rt�= 242
� ,�,,- - -
> Adjust second story gutter to divert 1/3 of roof flow to al�ey � � Downspout to drain to grass �
�
._—_ ___ � .�t, ,,r cR , ,_ � ___� ���� ��� ��s _� ..�_�� '� ���� ���s�.....����.����•�- z
� � West Lroperty '' � � �
� � `. Line 161.5' � ,_ i .P t�-n
� � - 1,�., �� � IL P/L �- /L�� PIL� � I �
� �`� � �
�c 8 � �\\\\\\\\\\\\\\\\� I �� � "?30' ,... 83 9 15/16� . ., . � J 15' � �
�
r
�
maintain existing downspo�t, ,�i
�, ,-� .-. : ,� �-� , , ,-:, � r. �-n-.-� rY��
Roof drainage to be collected and
hard piped to street
��,-»,.� ,-.__".w_ , ,�.,�a � ,��_>_._. , .�.s.,._�_
9 — �� --��,
East Property ��
Line 16i.5'
� „-. . -�. �-.� . , . �� �. . .
�
� � Install "drain pan"
r D ;
� � to carry water to
�
� �: street
A rn,
A �`� Slope ar1%inin ,
< "�:
rn �
� t. .>_, �_._,,,_:
__ _.___
_ _ _I _
I \ �
� , ,-_�� � � ,Y.-Y �, V �.� r� � �-.
� �� z > Downspout to drain to front of lot ?
� J
�r. r���,, ..,,. �.����.����.��,��.a�.�a���_� �
�Proposed concrete flat woi k � "
r inside red lines -
825 LaPorte Ave. -V2
`o
�m
��
o>
F
o �
f w
�wo
od� -
opQ �
��O O
z
�
�
w
�
�
o�
��
No
<LL
DATE:
8/11/18
SCALE:
t°-ia
SHEEf:
5P
ATTACHMENT B
PRECONSTRUCTION SITE PLAN AND PHOTOGRAPHS
Pre construction concrete locations
r cn
3 �
(0
? �
O �
o �—
�
co
�
r 4-�'0
r m
�
�—�
Existing House
Total 5Q. FT. = 1,932
Main LVL 5Q. FT. = 1,312
Upper LVL SQ. FT. = 620
Existing Garage 5Q. FT.= 122
Existing O�ce/8onus Rm. SQ. FT. = 418
Front Half of Lot 5Q. FT. _
Garage = 122
Office/Bonus Rm = 242
Proposed Rddition/Remodel
SQ. FT. of Addition = 200
Total SQ. FT. of Home = 2,132
Main LVL 5Q. FT. = 1512
Upper LVL SQ. FT. = 620
Garage 5Q. FT. = 286
Govered Porch SQ. FT. = 314
5Q. FT. 5outh (rear lot) of Genter Line = 5Q. FT. South (rear lot) of Genter Line =
Residence = 1,932 Residence = 2132
Office/Bonus Rm = 236 � Garage= 49
Garage = 0 (No{e�Lot drainage to remain Govered Porch=190
substantialiy unchanged.
The 6arage that will be
replacing the existing is the
same footprint and no
modifications will need to be
made to the existing grading.
r �
-P�� 54' �� -
- �—'f' Breakpoint ,
8' � � \ \�
� '��. \ o _
\ �� � � �� N
�� \\' m \ ���;
��\����o
ed�ii,�.,- r �
n�i�
��-Em ��.�,
Front Half of Lot SQ. FT. _
Garage = 231
Govered Front Porch = 152
West L'roperty
Line 16�.5' �
829 LaPorte Ave
REAR SE�BALK= 6-�
FRON-5ETBAGe= �5-FT
51�E 5ET0AGK= 5�F-
� z
� (D 7
3
_.,, .... O M
_� isa�— —� — ►; . " _ �
F�_ �—�-- FIL FIL =IL =�.L F;L—` F�L Fi� F_
8reakpoin�
East Pro erty I
l�ine 16l 5' " � z ,.�._�,,, �
, ='d",e��
Garage/Govered porch Elevation of finished floor (FF) is b" above gra�e LaPorte Ave
House addition FF to match existing house FF
�
N
�
A
�
O
�
�
rn
<
rn
r
D
-tl
O
A
m
<
m
0
,m.
�>
S
o �
f g
_wo
od� —
opQ �
��o 0
z
�
�
W
�
�
o�
��
a0
DATE:
ii/z�iis
SCALE:
,•-,a
SHEET:
5P
a
'�'�
_�
� ' _ - -�_ 1-a
N
F � _�'
� _
_ � � �t,
� +" k
� ,� � �,
r. /�_
� Y .1 ��
'�L� I
}
a ,
. •I r
�:. . � � �.�
� 'Y
t , .�, -
� �„
- .
� -'�
,��
�j� , .
w�� ��: . �
1 r -
y ' ��__ y
��
� �
• �,
� _ �...�.i's �
`*�C'�; � " ' ` _
e�.e
..�,' • _���. ,.,
�".•
- -^�I,�
� ' �'�� I�IICIII11111i.
.
�
,
�._�
f
� �'�' •
w un" ���'�� +•�i��� \ � �- �
�'� �, �• '`+� .'�� �-�
����.s ` f
-� �����p :��
,�; . .IP�,. �,._q.ai,. ,�" , .
�,v�t.,�;,: 1 � "` �� �. ti .
� � yt cl �� ��' '� 4 ;
• ,a,•}._� M
a
� ,,�r ,i, ^ ��. ` � ryc
� ' , � ��:� � n
� , �; A. �r� ��;:
. ,�
�
��
\
. � \��,
' ^ `.��
�� , � � � i
�� ..
_ � �
'k:, �� �r,�� f ! ���
� .��r
� �' "•' �c'�.;�,, . �
�
,�
.�
�..
1'N.Y�.•
. .2a`.�i
f
�
� ,
y
�
a � a�`�
wr
'a, , �' . �,
a.Y,sr�r � ,���+
�,.,, ,
f ;i
��"� ��.
� , .s
��.� ,�.:f.
� �¢, ,
i •���,'1,.
�
+�.:� ��` ,
ti � ' `.
:. �
, , ,. ,
0
'-+! :.. i . � �;L �s,v�f �;� ,.P - � � � �
4 � Y
� M ���b/ � � _� J,��� J �, ��. '' i . . . `
`- ;��.� c S1 ��•1t�•,� '��� ..M ; ` :
� , ��� .i.'��r' ���' ,
. � + �i :.• = '�r` -
• . ,"',' .�+�:•� ,��� s, �,.- _
: . �' -�y, � � � • • � �
. � � 1's t`. . , •t
� . .� -
_ � � 1' � � ) .
�� r A 'i
. t ` a.�. �
..: _F'rr, `{ ` :i��+_1 ', �f •' �
` r� �' Y �. f • ' '1�tM � ��
�.��' , ~ '� t • � • y �� .1
�,sr• �: •l � � •+1r�� �
� -'�•,
��y /� � � f
�� , ,�
,
,
-� ��- � .
�.
�\` � 1 r�
.
� . �v , �',; .
\ ,` � ►�14 , .«'' .�'
�
� � �
� ' ��
I ,
,' 1 I �
� �' \_ � _ __ �� _ �i � '�,'
. . .��
- �,4� i
w
a -�
y
-''�T '1�" . � ' Y -
. Y� � !e si' + 4. �' �r��,«� ��� i
i �►. .����-���' •-�, I !
—.. �.... 'i . � �f-:
' �. ;r .� . -. r�-.. �'`-
�.r � �t� v }r�• �' .. • � -�'! I
� �... ' � _.. � " • �� �
f `� f ' o��Y � �.` -. �•
� I 1 - � � '' ^ . - ~ ` .
\' / . • - . � .� _ , �
. ' _t _ � _n
�
1 , ��� � F� . . ;;yy'
, - . ,, :� � �'
�— +�' `' � ' '
1f��a��' � i'� � "• : • � , , � ° �`;• � .
�
_ ' /
..Ai�.�l,.�'`: � :�'; �� ���
1 �
I �
i � � \ v- ,
/ �i` ,+�
� � � � �� ' � � --
�I
~ �'`
J
, � � � ' � -����� �
_; • ,
�' � �� ��� ��
�• y�. �� � � � � �( i�' ..r ' / �.. .�
'ati '-���;t � - �� �L�
r;'����� '� _ � � � �,/ - ' - -
i._�. �h`1 "f I-r •�y�\ � 4 ��� /'�f� �./ ._. .. � ""
. ._ ` � x ' . �. �`` , ^-� f / 'r—�
�..�.�-�-'*i��y
--' i� - � � f�, � i I `, � . �.�., . , �.
\ • 'ti� ��
% � y; `� . . a., � ' . " .
7'
� .., fl J ti ;��,. . �`�+ �� / � I � .. � � �'4�
1 \
» ` > . i � ��� . . ._ � . `h. � . j�"�� . - � ' I �• i
' �`1�� �' .. , :��'� , � < '` "�.I�
ii i � . �' 1'�if � � � � � �°;�>. � � �''
� ��y�. ��% �' a r , 1 I L
.' rr''i�'1.,� i � ` � � �
I� �� ,• � i
I �qq• '' � 1 / ■ y i, _� .
_ � � i ; \ �, 41�t �. t • � 1 ■ �I� 4� • `�.�
� � , , S� ' �� ■ k: ■ l /� 'Y.i Y
i f � � y , , _ = .:y i �►R� �is::
: � , , ��� � `� � _ �` `
;,� yy : :,� � � - � ` � .. � .�
. i � � - _ /' � 3_ ;�, • V'.c...._ .
—g,
'/ �. - _ .� -- _ � - �.
. . s�� -��� � 7' � J
' � .���. . �j� r7 � �- -�� � _ _ `
, �� �'�� � -�04 - �
Ar ' I � . -.. s � ��'�
� �.
I � � I'� - _ ��� y� - -. . �}�. _ - �� ��^� �1�
, .I� � � l�� , r�.��f�� i� _ - T�