HomeMy WebLinkAboutCouncil Workshop Minutes 11.25.2003 MINUTES
COUNCIL WORKSHOP
NOVEMBER 25, 2003 6:30 P.M.
COUNCIL CHAMBERS
A Council Workshop was held in the Council Chambers and called to order by Mayor Bud
Johnson at 6:30 p.m. on November 25, 2003.
COUNCIL MEMBERS PRESENT:
_x_Lauren Van Roekel _x_Doug Poehls
_x_Ken Olson _Mark Mace
Gay Easton x Daniel Dart
_x_Dan Mears x John Oakes
OTHERS PRESENT:
Jan Faught Becky Shay,Billings Gazette
Mike Zuhoski Larry McCann
Jody Guillaume Steve Klotz
Dick Fritzler Kirk Spalding, Engineering Inc.
Chuck Rodgers Mary Embleton
Lary Tanglen,Laurel Outlook Mark Anderson
Public input
Citizens may address the Council regarding any item of City business not on the agenda. The duration for an
individual speaking under Public Input is limited to three minutes. While all comments are welcome, the Council
will not take action on any item not on the agenda.
• Jan Faught distributed information from Industrial Communications & Electronics
regarding a repeater site for the Fire Department and the Laurel Ambulance Service.
Aviation Technology Week
• Chuck Rodgers is the liaison for Aviation Technology Week, which is scheduled for May
10-14, 2004.
• Chuck distributed an overview of Laurel Aviation and Technology Week.
• City of Laurel has provided garbage service, traffic control, and port-a-pots for the event.
o Chuck asked the city to increase the number from 22 to 30.
• Chuck thanked the city for their participation and support of Aviation Technology Week.
Appointment of new police officer
• Mike Zuhoski introduced Jody Guillaume,the new police officer.
• Jody has served as a Laurel Reserve for one and one-half years.
• Jody has completed the Academy and will become POST-certified in one year.
• Appointment will be made at the council meeting on December 2, 2003.
Update on abatement of property
• Lary McCann explained the opportunity for the City of Laurel to obtain the lease to the
property at the comer of Main Street and First Avenue.
• Dean Rankin will relocate his store to South 4'h Street.
• Lease from the railroad would be $15,000.
Council Workshop Minutes of November 25,2003
• Would allow the city to open the underpass and do away with the sharp corner.
• Would allow more room for a left turn lane from the underpass.
• Possible to use funding from the HOME Grant for community development.
• Scale leases would not be affected.
• Dealings with the Department of Commerce and the Montana Highway Department still
need to be addressed.
MDT Update
• Steve Klotz stated that MDT plans to install a left-turn signal at the stoplight on Main
Street.
• Steve stated that Urban Highway Funds could only be spent on the urban highway
system.
o Includes East and West Railroad, which need replacement.
• Steve explained how the funds could be borrowed from MDT for the projects.
o Additional funds would not be available until 2008 or 2011, depending on the cost
of the 80' Avenue Project.
Sign in Firemen's Park
• Community members have expressed a desire to honor Laurel community members
currently serving in combat situation overseas and those who have served in the U.S.
military in the past.
• Proposal to erect a sign in Firemen's Park listing the military personnel serving.
• Proposed sign would be 8 feet by 4 feet.
• Sign will be available soon for veterans and current military personnel to sign.
• Sign will be located on the east side of the Chamber of Commerce building and will not
be a permanent sign.
• Resolution for the sign will be on the December 2"d council agenda.
81" Avenue Project, Part II: General Proiect Information/Storm Water Issues
• Kirk Spalding, the Project Manager of Engineering, Inc., distributed information to the
council.
• The proposed scope of the work includes total reconstruction of the segment of Eighth
Avenue from West Main Street to West Seventh Street and partial reconstruction from
West Seventh to West Ninth Streets.
• Improvements to the segment of Eighth Avenue between West Seventh and West Ninth
Streets would include reconstructing the curbs at the major intersections, new lighting,
new traffic striping, and reconstruction of pedestrian facilities to meet ADA
requirements.
o Needs a 20-year design life
o MDT project is for surface and stone drain improvements.
o City project is for water and sewer replacement.
• The presentation included the following items:
o Site layout, existing vs. project final
o Source/area of storm water inflow.
o Definitions of peak flows/hydraulic concepts
o Italian Ditch vs. Italian Drain vs. Laurel Storm Ditch
2
Council Workshop Minutes of November 25,2003
■ With this project, the engineers are not looking at improving the Italian
Ditch (Italian Drain — Laurel Storm Ditch) from the 8` Avenue Ditch to
the River.
■ The engineers are looking at not aggravating the existing conditions from
the confluence point of the Italian Ditch and the 8t'Avenue Ditch.
• The best way to do that is to get that water out of there, keeping in
mind that this water would most likely find its way down there
eventually by going over the top of West Main Street and other
means in its current state.
■ Mayor stated that the statement that they are not aggravating the existing
conditions could be changed slightly that they are not addressing the
conditions.
o Recap of previous studies specific to Laurel
o Italian Ditch flows
o Existing and proposed storm water contributions from 8`s Avenue
o Flow capacity of restrictions from 8"'Avenue to the River
o Owner of restrictions in Italian Ditch from 8t° Avenue to the River
■ Kirk stated that the MDT would have to address this.
o Basic components of the proposed overflow connector to South Pond
o Schematic of system and major components
o Ballpark cost of the system
o Time to design the system
o Time to construct the system
o Ongoing maintenance associated with the overflow connector option
o Responsibility of ongoing maintenance associated with the overflow connector
option
■ Kirk stated that this would require an agreement between the MDT and the
City of Laurel.
• A copy of the handouts will be attached to the original set of minutes in the clerk-
treasurer's office, and a full set of the project plans is available in the Public Works
Department.
Police car agreement with the City of Billings
• City of Billings will lease a car for Officer Pitts to use as a High Intensity Drug Traffic
Area(HIDTA)vehicle.
• City of Billings is willing to insure the vehicle if the City of Laurel reimburses any
damage costs.
• Alan Hulse, MMIA,reviewed the contract.
o MMIA does not insure the City of Billings.
o Alan advised that the City of Billings sub-lease the vehicle to the City of Laurel.
o Vehicle would be covered under the MMIA insurance for a minimal cost.
• Contract will be reviewed further.
Clerk-Treasurer—Mary Embleton
• Mary distributed information regarding the auditor's remarks, wastewater reserves,
administrative charges,the ME&A letters, and the HOME Grant Program income.
• Auditor's remarks
3
Council Workshop Minutes of November 25,2003
o Auditor's remarks are written suggestions on how the city can improve
operations.
o Preliminary Report contained five reportable conditions, seven other matters, and
one Findings and Questioned Costs.
o Final report will be issued soon.
■ Publish notice in the newspaper
■ City to issue response in thirty days to the Department of Administration.
• Wastewater reserves
o Background on Bond
■ Issued in 1991 for$605,000 for twelve years
■ "Refunding Revenue Bonds"
• To pay off 1983 Bond Issue
• Lower interest rates—9.4%to 6.3%
o $75,000 Bond Reserve can be transferred to Replacement and Depreciation
o $5,300/month set aside for bond payments also available for R&D
o Current R&D is $156,000
o $10,500 for sewer improvements can be added also
o Total needed for CDBG is $268,000
o Need to propose how to put savings into operating.
• Administrative charges
o Water, sewer, and garbage pay for General Fund services:
■ Legislative
■ Executive
■ Financial
■ Legal
• City Hall building
■ City Shop building
■ Dispatchers
■ Public Works Director
o Budget/Finance Committee will review and discuss administrative charges.
• Explanation of two letters from Montana Engineering and Administration regarding the
CDBG Grant
o Budgetary Amendment proposal
■ Accounting numbers not appropriate
o R03-112 already amends the sewer budget
o Tracking of Grant dollars
■ Grant administration different from city accounting purposes
■ ME&A will track line item costs.
• HOME Grant Program
o Casey Joyce is the administrator of the Grant.
o Program income sources
■ Participants did not qualify to stay in Program
■ Repay grant proceeds from sale of home
• Four of 31 participants have repaid
• $55,000 returned to Program
• Must be spent on HOME Programs before new grant monies can
be distributed
o Homebuyer Assistance
4
Council Workshop Minutes of November 25,2003
o Rehabilitation
o Program income expenditures
• Cannot be used to apply for new grant
■ $4,900 paid to Big Sky Economic Development Authority is not eligible
HOME expense
■ General Fund will have to reimburse HOME Fund.
o New agreement with BSEDA is needed
■ Current agreement is "open-ended".
• HOME requires a stated maximum fee for administration.
■ Resolution for new agreement on December 2"d agenda.
CIP
• Mayor explained the concept of the CIP.
• Council needs to review the CIP and make funding decisions.
o Budget process can be used to rank and fund projects as appropriate.
• Council discussion regarding the CIP
• Proposed projects for council funding are:
o Repeater stations for the Laurel Fire and Ambulance
o Comprehensive Park Plan
• Discussion regarding need for a long-range equipment replacement schedule
• Mayor stated that resolutions would be prepared for the repeater stations and
comprehensive park plan.
Executive review
• Discussion regarding Mayor Johnson's impending resignation.
• State statute allows thirty days to fill vacancies.
• Discussion regarding need for a smooth transition and how to accomplish it.
• Mayor's resignation will be considered at the December 16t' council meeting.
• Council will appoint a new mayor.
Resolutions:
• Sign in Firemen's Park
• Police car agreement with City of Billings (will be removed from 12/2/03 council
agenda)
• Resolution authorizing the Mayor to sign an agreement with BSEDA for administering
the HOME Program.
Announcements
• Dedication of the Laurel Lions Family Park open-air pavilion is scheduled for Saturday,
November 29d', from 6:00 to 8:00 p.m.
• Discussion regarding a Joint City-County Meeting.
o City of Laurel will host and schedule the next meeting in January 2004.
• Discussion regarding workshop with the Local Government Center.
o Mayor and council will participate in a workshop on Saturday, January 17d'.
o Mayor, council, and department heads will attend the workshop on Saturday,
January 240i.
5
Council Workshop Minutes of November 25,2003
Attendance at the December 2"d council mectin
• No discussion.
The council workshop adjourned at 9:12 p.m.
n ,
Cindy Allen
Council Secretary
NOTE: This meeting is open to the public. This meeting is for information and discussion
of the Council for the listed workshop agenda items.
6
Eighth Ave — Main to 91h Street
City Council Presentation
November 25,, 2003
{ 1 . Overview and Scope of Work
The project was nominated by MDT to include reconstruction of the
existing road section to mitigate high maintenance costs, lack of ADA
(Americans With Disabilities Act) accessibility, surface deterioration,
lack of storm water intakes, and inadequate storm drain size. MDT
personnel conducted a Preliminary Field Review on February 4, 1999.
The proposed scope of work includes total reconstruction of the segment
of Eighth Avenue from West Main Street to West Seventh Street and
partial reconstruction from West Seventh to West Ninth Streets.
Improvements to the segment of Eighth Avenue between West Seventh
y and West Ninth Streets would include reconstructing the curbs at the
major intersections, new lighting, new traffic striping, and
reconstruction of pedestrian facilities to meet ADA requirements.
➢ 20-yr design life
➢ MDT project is for Surface & Storm drain improvements.
➢ City project is for water & sewer replacement.
fr
2. Site layout, existing vs. project final
Ab
TYPICAL SECTION NO, I
[JA 11.1
W
Y -F(-, T f
fwl.
.. .. . .................
rl h rf)
. ..............
m "S?-A r............. .....
-m-T . ............
L'i T.,:AD 04
x�---
...........l..w.........
ci E
61 ft 9 iL L
MP V.FOis
H11 150
A
RMERIM AGG, TREAT,
6.4
L--1
TYPICAL SECTION NO. 2
1 -j(j TO
to T
di.0 N.P, Tip,
...........
..-J,. F
2z I
AAr.
WX U-
t.j, _� -- - - --- T'--�=-- --+`+--- 4,f�', W!
ra .E
A
r,ul LUH!wl_�
E
HICMT b'I
WD W:c rn"[,
RL, OR M.
L(i
4L
00)R E CiA ILL
6 1 T U 1A 1\1 0 U S
TDRIA
IT
AffAW
u T&Tl���
-----------
2c. Location of existing storm drain system
and water/sewer in relation to construction
section.
.t Main to I st
Is
Won masit--p
was "Not
LJ-
qr-
INK
-MA*TiVM
"am
wm mem um
. ... .... .... ...
c[N� F �, �"' [#t#�r� i��}�ies �=E#r !i[E�lElw![ 11![E EsirelE lEl■ t � �"� � � "'��
p
uZ O� �s
I
nd to 3rd
irg
T
k 3___,
IF vs@ a ass alls @-.I a
1 77
:7, 1 7-,
-wk ZU-t
"Ps
t,
dl�
v
A
alr
e -
AQI WWd-1 14,
^ + �ati�trrrrrsrrissr�s sror_rrrirrrrrrrrr�`srers . slsaa� si" "�*^ iri rrrr�
�...
wrrjriEl.ifrrtigrflfr�rl�l��lrl lrrsr USElr�ar rrrrall °vf
lmmaogovt
-77
Pi0�
4 th
to 5th
r _
B-
i
s„P
OWE
Or
sv
r7l
yds.
i ssiaaairaii aaa asasa ssasa■siiIW
a�essraea 'm `
�i '4
mme
�.4* [ rirl?'r r�i� � i}gists t�rr�rrrr■ e; tsi `-...: ;
"
q19 01 ql�
6th
t0 7th
�, � � � ■�yz�Ji
3 r.
APP-
eMAE
Esc'.
Mi b.,
7th to 8th
A, n
7 2 0, xr-`
34
-� o.
" b = ` ''r e ■ �re1� of �. rrrr_irrr■ iiiiurrrrrrrirrr�ii r —
;. r
HUM -
.�> NE fin' lapse.
-
;z. c` -
m. -_ -� _�/ !41i#■�YifliiifiiliY 1L;/■ll Eiiiit !!// ! filth!!///!ii - :- �if .
�.
lr.
wimi
ISM
41
u
o1 4
u�
2c. Storm water layout — Existing vs. Project
final (see handout)
3 . Source/Area of storm water inflow. Constant
vs. storm event springs vs. runoff)
AF
Cl9 3223 n
inn sn�. .. - - AVA
�' I IEELL�+��III1tt� -0
HO
'' �,,•,� EXCSTIN AGE I .
w
. ,
. P3 p
L'
- BllVY,[■L� j
i u 12 L4
L M7
AREA J BaoAspi h
34.542 ha (85.355 ac)
y
. LOl CE31 J�1 f
U 3 URE: I ERR FP sp-
AREA K e
-4 g, 6.83Tha(f6.894ac7
3 A $a
F rat f �sg
FIGURE 1 STORM DRAINAGE MDT RESP❑NSI
SCALE 111000
3 .2 Collection area changes
12th
car;-
•Y
Xv
a R 11 L�
9, <48 3 ) Eis1 ili
a
� I
41, cy �-. ... 1ai:d
ne j AREA I
! Ave. ,
71,123 he (175,748 ac)
! \ rt3
EXISTJN AGE
P L4
C
I 8.446 ife!s
rose ¢.7
f AREA b a
! 7.895 he f19Sos act P, i
aaE
e�
7.137 ha (7 36 �
i
P M9
AREA 4 n;
6.463 he (15.970 cc)
P3
?r7rECFPri + AREA 3. ���
J 7,315 he.<18.076 nc) c. v Smmp
t. IW49 he 112,971 a ;
ot
FIGURE 2 STORM DRAINAGE EXHIBI
SCALE
4. Definitions of peak flows/hydraulic concepts
➢ 5 yr, 10 yr and 20 yr storm events— are those precipitation events (storms) with
rainfall intensities expected to occur only once every 5, 10 or 20 years for a selected
duration, respectively....(see next two slides)
➢ Peak flow— the highest flow rate for a watershed during the selected storm event
➢ Time to Concentration - time for runoff to become established and flow from the
most hydraulically remote part of the drainage area; this does not necessarily equate
to the furthest distance from the outfall. This time is used in conjunction with
hydrologic data for the design storm to determine the intensity for calculating the
peak flow.
➢ Rational Method Q=C14) is used to determine peak flow for watersheds under 200
acres in size; where Q = peak flow, C = runoff coefficient, i = intensity (incheslhr) for
the watershed time to concentration, and A = area in Acres.
➢ Inlet flow & associated lateral pipe flows— based on contributing street surface area
and a portion of adjacent property (1/ block away from street)
➢ Trunk line flow— cumulative flow from inlet pipes and intersecting ditches
4. 1 Rainfall Intensities
for n s
TABLE 2-4
INTENSITY - DURATION FOR BILLINGS, MONTANA
INTENSITY IN INCHES PER HOUR
AT SELECTED RECURRENCE INTERVALS
TIME 2-YEAR 5-YEAR i0-YEAR 25-YEAR 50-YEAR 100-YEAR
1 min. 2.82 4.54 5.66 7.09 8.15 9.20
5 min. 2.82 4.54 5.66 7.09 8.15 9.20
10 min. 2.OB 3.20 3.95 4.89 5.58 6.28
15 min. 1.68 2.62 3.24 4.03 4,62 5.20
20 rain. 1.45 2.29 2.84 3.54 -4.06
25 min. 1.23 1.95 2.43 3.04 3.50 4.57
30 min. 1.00 1.62 2.03 2.55 3.95
35 min. .93 1.50 1.87 2.35 2.71 3.06
3.32
4O min. .85 1.37 1.71 2.14 2.47 2.79
45 min. .78 1.25 1.55 1.95 2.24 2.53
50 min. .70 1.12 1.40 1.74 2.00 55 min. .63 1.00 1.24 1.54 1.77 2.26
00
1.00 hour .55 .87 1.08 1.73
1.25 hour .49 1.19 1.36 1.53
.77 .95 1.19 1.3fi 1.53
1.50 hour .44 .68 .83 1.03 1.1g
1.75 hour .38 .58 .71 .88 .99 1.32
2.00 hour .32 .48 .Sg .T2 1.16
2.50 hour .28 .42 .50 .62 .70 .91
3 hour .23 .35 •79
6 hour .15 .21 -42 .52 .59 .66 ,
24 hour .060 .079 .092 .1113 .126 -37
.141
N0TE5:
Values from 5 minutes to 3 hours from -
Mark M. Peterson, A Statistical Anal sis of Short-Duration
Precipitation for Bfllinas, Montana, Montana State University, Bozeman,
w�ntor
Values for 6 hour and 24 hour from
National Weather Service, NOAA Atlas 2 Pill'"',,,III itation - Fre uenc Atlas
of the Western united States Volume 1 - Montana, elver prang,
III
o
0
5 . 1 Italian Ditch vs. Italian
Drain vs. Laurel
Storm Ditch
4Z,4
-
Qv F- {{ r �Iti � ___._r. ,� � �� i•` �• y -� - ads �ay.'' ise�C�' _' '�.ir'f Zi � 1 .' _
,.� 1 / 4�f '..� ��,,,,.�'' � :;� _�f'. - •-«. "� mac— 1�, �« vs, � ,'. ' +v
41 I 3 ,�.Lam:sy i,�,� i V•Y� _-! -__ __ r .- - - ``� 'f' _ -
'�`� - 'r�r✓-' ,�.� � � ��:^'.may.. _ S V ._ '35 ".`�' ��.•' - _ V.y_�.
<Qa.� J ,'ymy'�° - �• 1Zv„ '- �`1Q ,f / �: �r'^3:t� - r't' - _..� �) - - -
'r=-- ! �•�'-'�,� -f�--��1=_ram=`-._ _._..-.._- •y^._.,;�. -_ * - .,`�_ F - `� .`"''�-.;- � ,y-`• .
L12to
YN
t
P ND
AN
.-..�.. w •a�I(1-`
N� -� ........... LAUREL STORM SEWER
8th AVE. DRAIN DITCH 2,
# i` +►°� �-- i' -- ITALIAN DRAIN
PROPOSED INTERCEPTOR DITCH4s
ITALIAN DITCH or.LAUREL STM.DITCH
...---.. I•• _...
WATERSHED AREA BOUNDARY
27
�o
ay 28
I '
i LAUREL'S EXPANSION AREA °'° 2...# :'
ITALIAN DRAIN
WATERSHED AREA ' r
Li/`-y-49G Is.
f.;
5 .2 Ditch Definitions
Brief history of the Italian Ditch, Italian Drain, Eighth
Avenue drain and Laurel storm drain ditch according to information
presented in the Storm Runoff Capacity of the Italian Dt�ain, as
prepared by HKM Associates in 1980:
The Italian Ditch originally ended approximately I mile
,0i west of Eighth Avenue and %2 mile north of W Main Street. At this
location irrigation wastewater merely spilled out the end of the ditch
and onto nearby properties. Then, in the 1930s a ditch (Italian Drain)
was constructed from the end of the Italian Ditch to the south, across
W Main Street to the RR tracks and to the northeast where it
eventually ties in to Eighth Avenue storm ditch as it does today. The
Eighth Avenue storm drain system was originally an open drain ditch
north of W. Main Street, but was later reconstructed into the existing
Eighth Avenue storm drain system, which collects irrigation
wastewater, spring water and stormwater.
6. Recap studies s ecifi specific to Laurel
Hazard Mitigation Plan" (Prepared by Montana Engineering and Administration, PC;
anuary, 2002).
i. Suggested many improvement scenarios to reduce and eliminate flooding potential
in Laurel (slide)
ii. Plan was formally adopted by Laurel City Council on March 19, 2002
Runoff Capacity Analysis of the Italian Drain" (prepared by HKM, 1980).
i. Recommended 3 levels of improvements, the best of which, would accommodate
only 300 cfs. of flow in the Italian Drain (100-yr peak flow was estimated at 650 to
1250 cfs)
ii. Included a diversion structure between 8tb Ave and Golf Course Road for one of
the alternatives
rehensive Storm Drainage Plan" (Stevens, Thompson & Runyan, Inc., October 1974).
i. Recommended increasing storm drain on 8tn Avenue to gradually increase to a 72"
pipe at the south end of the project
4a
Y 6. 1 Flood Hazard Mitigation
Plan
..........
ST
OP
I. ! I oa
New 21" Culvert EOLORA00 AV8_
PROFILE BASEI Rg-i
�J :-iA'11T OF `I-leri Main Srmr[ '. y ~29b'1:� •- 5�
( Ove;f'aw FiLr', E I..INF ZONE E'�, ZONEI! 1s�9_91:
1� DETAILED J 6i ��
STUDY
'?nor 3300 y.
IG H VS HWAY ,0 -._:_.,.....- ......._._—_.._.......- _....._..._ _____
' WEST M11AIN SY R£ET
SOUTH FIRST
Provide co lectcr for north side cf cs�sTREtT _ ZONE C
Nest Mein to Figgins Pond. -: -- -- , —
j
A A
- -� -
}
, E5T LAUREL ��� %� "�� ZONE r •-- -
f �.Nsr j z
IrvT�lxr"�far,ce� ZONE ; Al
All w Ic3i
J3T95
= Culvert t._, [*V b N b E -
_._._. »
• ./ _— _ _ _
{ P�
all
,....5 �^TH4R
I„ c
--'
'`b
UAN 0
"`.r 'I ZONE B �.4
2 LANE A CON TAIIV ED `--`f,•—.r - ?�
-,,; :! 5 „FOURTH 5TS 4
1N C3-IAHNEL �Wveri �-�` ''�—"" :%""- _ _— _._._.._
1...: .AIT OF 4r ._ i... ,,..II. AVE
TJDYG rF� ! ZONE B—
L}
I
FIF, s _ _..-.....
s,
,... .�_ DFy'( 5 —w - - _ -- 700 YEA
i
/ i3 D{�l
C
ZONE AZ M THIS AREA TO�j,iARftOYSf TO SHOW AVE C'
Z �� �•` Cfl NT
FORREST
TO SCALE ANO DOES NOT EjiCEED BOUNOAA ES
DELINEATED. II ' - - - NIN ST
ti -.
0
�� rflViD? CO`zrriCr from i:"3 LO
OP I[ON L— : s Dro Under RR and o L
ail; U� cu
i red
4 --Gcr,skr u t f Ditch
Lend, f_' 0 4 4: Y
ly overflow, ryes town. have an rvar=.`l;w im;r f[c;v •, Use Lcure? Pnr.c� f
J �`
ores bra€ }. 7
El
C'NE Al IN Tt!]5 A
. .. _Z:..Y CIp ii _;NARfiCSV TO 3FI£jbJ
rc;_r.r,� i.
� I' .:ANr, DOES NOT
Apnrox;im to flo,vs taker frflT = > !
1 9 2 F EUA study. '�- = - ReceristrUCt CJ:VE;rts/dre-inane west
_ Sou: s t Avenue arc under Sc� t
:l::y .`L '.•KS'rtr.*if:F RAT' 1.AF•- r-_.,.'f T.. •-,Gi l.3:: tile?':l..'£,',
.CIT CF LA:'FE„ MGY`A!.H h?^^�ii:[`Jhf� $CALL
ci.LQNS[Oti:C,.^.tiwT4' �'7 " � _
'
I
7, 8 & 9 Italian Ditch Flows
(from HKM)
07. Flow capacity of Italian Ditch.
♦➢ 80 cfs due to constriction at City
maintenance yard
■
08. Constant flows in Italian Ditch, seasonal irrigation
water.
♦➢ 25 cfs average irrigation flow; only allows 55
- cfs more before flooding by City Maintenance
Yard.
09. Peak storm flows in Italian Ditch, storm and seasonal
irrigation water.
♦➢ 5-yr storm = approx 350 cfs
♦➢ 10-yr storm = approx 400 cfs
+➢ 100-yr storm =estimated at 650 to 1250 cfs
� 0. Existingand proposed storm water
contributions from WhAvenue
xisting — 63 cfs limitation due to storm drain trunkline size
roposed — 94 cfs of capacity due to upsizing of system trunkline
storm drain inlets on both sides. and new
i. Key here is that we are reducing floodin
potential of pro erties alon g
p g 8t� Avenue,
especially at the 2°d and Th street ditches.
Eighth Ave should collect all of the
stormwater during the 5-yr storm event.
4
11 . Flow capacity of restrictions
� y coons from
Avenue to the river
➢ Culvert under City Maintenance Yard — 100 cfs (HKM report)
p )
Culvert under 5te Ave South — 90 cfs (HKM report)
Culverts by Town Pump — 80 cfs (HKM report)
Culvert under I-90 — 100 cfs (HKM report)
t
12. Owner of restrictions in Italian Ditch
from WhAvenue to the River
➢ Culvert under City Maintenance Yard —
➢ Culvert under Ste Ave South —
D Culverts by Town Pump —
➢ Culvert under I-90 —
LGGGGGGG SNOIISafl(
13 . Basic components of theproposedp
overflow connector to South Pond
Reconstruct a short reach of the 8th Avenue Ditch just south of 8th
venue storm drain system outfall (south side of W Main St),
ossibly with a stilling basin design.
Construct a Headwall (with trash rack) in the ditch with orifices for
ow flow (< 63 cfs) and surge flows (> 63 cfs).
Surge flow pipe prevents mixing of Italian Ditch water with 8th
venue stormwater.
Surge pipe carries a maximum of 31 cfs from headwall to open
ditch (possibly lined) and perhaps a detention basin (for treatment of
stormwater) between Railroad Street and Railroad tracks.
Treated stormwater passes under Railroad Street near west end of
and and enters pond without scouring.
i
14. Schematic of system and major
Components (handouts)
15 . Ballpark cost of System
Construction based on current alternative: $350,000 + or -
Engineering based on assumed scope: $4000 + or
16. Time to design System
Design process could exceed 6 months to 1 year:
• survey
• agency coordination
• hydraulic analyses
• geotechnical investigation
• environmental including public involvement
• right of way and permitting
• agency review periods
•. . . . . . ..but nothing would be final until the
remainder of the 8th Avenue Project is complete
.Y
R
17 . Time to Construct System
Not long. . . . . .2 months, perhaps
It would likely be done concurrently with the early
stages of Wh Avenue street construction activities prior
to irrigation flows commencing in the Spring.
;L
18 . Ongoing maintenance associated wit
h
the overflow connector option
➢ Routine inspection after large storm
events (5-yr or greater)
➢ Clean trash rack as needed
➢ Cleaning open swale (south of RR
tracks) should only be needed after after
several significant storm events have
occurred. Very little sediment is
anticipated.
➢ Check pipe inlets occasionally for
vermin (beavers, muskrats) that might
obstruct the openings
19. Responsibility of ongoing maintenance
associated with the overflow connector option
DISCUSSION
MDT and City
Ilk QUESTIONS ?
?????? ??????