4. Resolution 5590 - Willows SID #345201 Ist Avenue East
PO Box 1997
Kalispell, MT 59903
Phone: 406-758-7720
Fax: 406-758-7831
www.kalispell.com Ipublic_works
MEMORANDUM
August 20, 2012
To: Doug Russell, City Manager
From: Susie Turner, P.E. Public Works Director/City Engineer ,5tr
Date: 8/29/2012
Re: The Willows Subdivision Stormwater Improvements
Background:
The Willows Subdivision experienced flooding in the spring of 2011 due to a plugged 12" discharge
pipe from the Willows stormwater detention facility. The residents of the Willows approached the
City and requested the City take over maintenance responsibilities for the detention facility and
associated discharge piping. The City agreed to provide this service based on the stormwater
detention facility and discharge system being updated to current City Standards. The improvements
needed to meet current City Standards include re -development, upgrade, and installation of the
following:
• Detention facility sizing
• Outlet structure
• Side slopes
• Offsite flows
• Water quality treatment
• Maintenance access
The residents of the Willows came to a consensus the improvements would improve and enhance the
subdivision and decided to proceed with the development of a Special Improvement District (SID).
An engineer was hired to develop a preliminary engineering report which provides a cost estimate for
the design and construction of the stormwater improvements.
On August 13, 2012, City Council participated in a presentation outlining the Willows stormwater
development and the proposed preliminary engineering report for the improvements. Questions arose
concerning the offsite flows (bypass flows) in regards to who is responsible for that portion of the
construction cost, and whether the City should participate in some of the offsite flows construction
costs. Following discussion, Council requested options for consideration based upon potential
participation in the offsite flows associated with the 18" pipe for this project. This report will outline
the percentages of offsite flows associated with this project and offer several alternatives for
participation and funding for the Council to consider.
The Willows Detention Facility is located at the downstream end of a large drainage area. Flows
from areas within the large drainage area can be broken into three sub -delineated drainage basins.
1. The Willows Drainage Basin (includes offsite vacant field to the north)
2. Muskrat Slough Drainage Basin
3. Leisure Heights
4. County Facility
The flow contributions from each sub -delineated drainage basin are as follows:
TABLE 1
Flow Contribution
Drainage Basin
Flow Contribution
(cfs)
Notes
The Willows
13.3
Post Developed 100 year flows
Muskrat Slough
2.53
Flows calculated from max allowable flows from
pipe outfall structure at Willow Glen Drive
Leisure Heights
6.39
Post Developed 100 year flows
County Facility
9.16
Post Developed 100 year flows
The preliminary engineering report outlined utilizing an 18" pipe to bypass the offsite flows from
Muskrat Slough, Leisure Heights, and the County Facility. The flows from the Willows Subdivision
were designed to discharge through the existing detention facility 12" discharge pipe and utilize
some of the flow capacity of the bypass pipe. The table below summarizes the flows, capacities, and
percentages of the pipes. The Willows will utilize the entire capacity of the IT' pipe and 36% of
the bypass pipe. The remaining capacity of the bypass pipe will be utilized by the other sub -
delineated drainage areas.
TABLE 2
% Contribution to By ass Pipe
Drainage Areas
Total Flow
Contribution (cfs)
12" Pipe
Contribution
(cfs)
Bypass Pipe
Contribution
(cfs)
% Contribution to
Bypass Pipe
Willows
13.3
3
10.3
36%
Muskrat Slough
2.53
0
2.53
9%
Leisure Heights
6.39
0
6.39
23%
County Facility
9.16
0
9.16
32%
Total
31.38
28.38
Based on 12" pipe at 0.3% slope with 3 feet of head
Please note, the figures used to calculate the % contribution were based on the preliminary
engineering and are subject to change, however the same methodology will be used once the final
design report is complete.
The preliminary engineering report includes the estimated total costs for construction, engineering,
and administration/financial, as shown in Table 3. Portions related to the bypass flows are
highlighted.
2
TABLE 3
Cost Estimate — Phase 1
ITEM
NO.
DESCRIPTION
EST.
QTY
UNIT
UNIT
PRICE
EXTENSION
101
General Requirements
1
LS
$10,300.00
$10,300.00
102
Mobilization/Demobilization
1
LS
$8,200.00
$8,200.00
103
Taxes, Bonds, Insurance
1
LS
$6,200.00
$6,200.00
104
Construct Pond Outlet Structure
1
EA
$5,000.00
$5,000.00
105
Construct Diversion Structure
1
LS
$15,000.00
$15,000.00
106
18" PVC Storm Pipe
1500
LF
$25.00
$37,500.00
107
Construct new 18" overflow pipe
1500
LF
$35.00
$52,500.00
108
Install manholes for overflow pipe
6
EA
$2,000.00
$12,000.00
109
Replace existing discharge structure
1
EA
$5,000.00
$5,000.00
110
Excavation to increase pond volume
1000
CY
$10.00
$10,000.00
III
Pond slope stabilization
3000
SF
$5.00
$15,000.00
112
Construct pond access ramp
1
LS
$10,000.00
$10,000.00
113
Construct pond access gate
1
EA
$2,000.00
$2,000.00
114
Topsoil and reseed all disturbed areas
1
LS
$2,000.00
$2,000.00
115
Rip -rap for outlet to river
200
TON
$60.00
$12,000.00
116
Rip -rap for detention pond
50
TON
$60.00
$3,000.00
117
Miscellaneous Work
1
LS
$10,000.00
$10,000.00
Construction Sub -Total
Contingency (20%)
Construction Total
$230,700.00
$46,200.00
$276,900.00
Engineering Design
Construction Engineering Services
Wetland Study
Engineering Total
$27,700.00
$27,700.00
$10,000.00
$65,400.00
Bond Counsel and Related Costs
Revolving Funds Deposit (5%)
District Reserve Fund Deposit (5%)
Administrative/Financial Total
$11,000.00
$19,628.00
$19,628.00
$50,256.00
Total Project Costs
$392,556.00
The construction cost can be further broken down into items associated with the bypass flows pipe
construction. Table 4 Proportional Cost Break Down, uses the percent contributions (calculated in
Table 2) to produce a proportional cost estimated for the Willows and offsite flows associated with
the three sub -delineated drainage basins.
Table 4 summarizes, a total proportional construction cost of $41,374.21 is from the Willows
Subdivision. The remaining construction costs associated with the offsite flow or bypass capacity is
$87,625.79.
Please note, the figures used to calculate the % contribution were based on the preliminary
engineering and are subject to change, however the same methodology will be used once the final
design report is complete.
3
TABLE 4
Proportional Cost Break Down
The
Muskrat
Leisure
County
Total Off
Site Flows
ITEM
NO.
Construction Description
Cost
Willows
Slough
Heights
Facility
Cost
Construct Diversion
$15,000.00
0
$5,000.00
$5,000.00
$5,000.00
$15,000.00
105
Structure
106
18" PVC Storm Pie
$37,500.00
$13,609.94
$3,343.02
$8,443.45
$12,103.59
$23,890.06
Construct new 18"
$52,500.00
$19,053.91
$4,680.23
$11,820.82
$16,945.03
$33,446.09
107
overflow Pipe
Install manholes for
$12,000.00
$4,355.18
$1,069.77
$2,701.90
$3,873.15
$7,644.82
108
overflow pipe
115
Rip -rap for outlet to river
$12,000.00
$4,355.18
$1,069.77
$2,701.90
$3,873.15
$7,644.82
Totals
$129,000.00
$41,374.21
$87,625.79
Percent Cost Contribution
1
32%
68%
Alternatives and Options:
Alternative 1: Find that the offsite flows are representative of new development impacting the
drainage system and finance the facility upsizing with impact fees.
Option 1 Elect to not participate in the funding of the improvements.
Option 2 Elect to participate in 100% funding of the bypass improvements with impact fees
covering the offsite flow percentage (68% per the example) and stormwater assessments for
the remaining portion of the bypass project (18" pipe).
tion 3 Elect to participate in the funding of the improvements with impact fees up to the
percentage associated with off -site flows (68% per the example) for the bypass project (18"
pipe).
Alternative 2: Find that the offsite flows represent historical quantities for the Willows Subdivision.
Option A Elect to not participate in the funding of the improvements.
Option B Elect to participate in in the funding of the improvements with storm sewer
assessments up to the entire bypass project (18" pipe).
Option C Elect to participate in the funding of the improvements with storm sewer
assessments up to the percentage associated with off -site flows (68% per the example) for the
bypass project (18" pipe).
Alternative 3: Deny the petition to form the SID
Alternative 4: As determined by Council
C!
Funding Sources:
Impact fees:
The City's Stormwater Impact Fee Fund has $669,236, as outlined in the fiscal year 12/13 budget
with two projects totaling $436,500 (though that is dependent upon new development occurring to
encumber these appropriated funds.) Even with these projects, funding would be available in the
Stormwater Impact Fee Fund.
Stormwater Fund:
Funding to support the construction for the bypass piping could be used from the budget line item
Designated Capital Projects. Designated Capital Projects revenues are allocated from stormwater
assessments at $50,000 per year. Ending cash in this line item for FY 12/13 is $465,844.
With Council approval for use of either source, a new CIP would be created using the estimated
bypass pipe construction cost with a follow up 12/13 budget amendment.
Staff Recommendation:
Discussion at the previous work session identified the offsite flows from neighboring development as
having a negative impact upon the drainage system serviced by the Willows Subdivision.
As such, it is recommend that Council approve the Resolution Authorizing the Willows Subdivision
Special Improvement District and participate in funding the bypass project with impact fees up to the
percentage associated with off -site flows (68% per the example) for the bypass project (1.8" pipe).
5
BE IT RESOLVED by the City Council (the "Council") of the City of Kalispell (the
"City"), Montana, as follows:
Section 1. Passage of Resolution of Intention. This Council, on June 18, 2012, adopted
Resolution No. 5565 (the "Resolution of Intention"), pursuant to which this Council declared its
intention to create a special improvement district, designated as Special Improvement District
No. 345 of the City (the "District"), under Montana Code Annotated, Title 7, Chapter 12, Parts
41 and 42, as amended, for the purpose of financing the costs of certain local improvements
described generally therein and consisting primarily of a storm water detention facility and outlet
(the "Improvements") and paying costs incidental thereto, including costs associated with the
sale and the security of special improvement district bonds drawn on the District (the "Bonds"),
the creation and administration of the District, and the funding of a deposit to the City's Special
Improvement District Revolving Fund (the "Revolving Fund") and to a District reserve account.
Section 2. Notice and Public Hearing. Notice of passage of the Resolution of Intention
was duly published and mailed in all respects in accordance with law, and on July 16, 2012, this
Council conducted a public hearing to hear and pass upon protests against the proposed
Improvements and the creation of the District. The public hearing was the first meeting of the
Council following the expiration of the period ended 17 days after the first date of publication of
the notice of passage of the Resolution of Intention (the "Protest Period").
Section 3. Protests. Within the Protest Period, three (3) protests were filed with the City
Clerk by the owners of property in the District subject to assessment, representing 3.45% of the
total estimated costs of the Improvements and costs incidental thereto to be assessed against the
properties in the District, in accordance with the method or methods of assessment in the
Resolution of Intention.
Section 4. Creation of the District; Insufficiency of Protests. At the next regular meeting
after the expiration of the Protest Period (i.e., the meeting on July 16, 2012), the Council heard
and passed upon all protests and determined that the protests made by owners in the District to
be assessed for the cost of the proposed Improvements and incidental costs to be financed with
the Bonds is not more than 50% of all of such costs in the District. The Council found and
hereby ratifies and confirms that the protests against the creation of the District or the making of
the Improvements filed during the Protest Period are insufficient. The Council subsequently
analyzed the Improvements in greater detail and determined that additional City contributions
toward the costs of the Improvements may be warranted. The District is hereby created on the
terms and conditions set forth in, and otherwise in accordance with, the Resolution of Intention,
but taking into account any additional contributions by the City toward the costs of the
SID #345 — Willows Subdivision
Improvements, thereby, if made, reducing the special assessments against properties in the
District. The findings and determinations made in the Resolution of Intention, including, without
limitation, those relating to benefits conferred, funding the Revolving Fund and District reserve
account and securing the Bonds thereby, and using the proceeds of the Bonds to pay or
reimburse the City for all or a portion of the costs of the Improvements and costs incidental
thereto are hereby ratified and confirmed.
PASSED AND APPROVED BY THE CITY COUNCIL AND SIGNED BY THE MAYOR
OF THE CITY OF KALISPELL, THIS 4TH DAY OF SEPTEMBER, 2012.
0101=41
Theresa White
City Clerk
Tammi Fisher
Mayor
SID #345 — Willows Subdivision 2