HomeMy WebLinkAboutA002 - Report on Stormwater Issues dated February 1, 1994 STORMWATER ISSUES
FEBRUARY 1, 1994
Several issues relating to stormwater are being raised for consideration by City Council.
These include funding type, design policy, project priorities, and level of funding. At the
present time the operations portion of the stormwater work involves two areas. The first
deals with the on-going maintenance of the stormwater system. Costs are currently
$95,000 for intake rebuilding, pipe repair, pipe cleaning, and other similar maintenance
activities. The other operations activity includes $11,000 for engineering personnel to
accomplish site development review and other related work. The Road Use Tax Fund has
been the revenue source to pay for the above operations activities. Previous capital
expenditures include $50,000 - $75,000 for outlet erosion control. Available balances in
Road Use Tax Fund or Local Option Tax Fund have been used to cover the costs for the
capital projects.
The 1994/95 budget provides for the creation of a stormwater utility as a means of
developing a new revenue source to address the proposed work to address stormwater
issues. The storm water utility would fund the operations (maintenance and engineering),
as well as capital projects. The development of the proposed stormwater utility is but one
of the stormwater issues being raised.
The first decision point deals with level of service. If the current level of service is to be
maintained, then creation of a stormwater utility is not justified. If the answer is to continue
at the existing level of service with an average annual expenditure of approximately
$160,000, then the costs proposed for the stormwater utility should be shifted to the Road
Use Tax Fund and the concept of a stormwater utility dropped. The shift back to Road Use
Tax funding from the proposed stormwater utility for operations can be accomplished by
dropping the concrete pavement maintenance capital project ($50,000) and reallocating
$57,000 from the balance of the fund. Funding for any capital projects could come from
fund balances as appropriate.
If the answer to the level of service question is that a greater level of service is desired,
then a funding source beyond the Road Use Tax and the Local Option Tax funds must be
identified. Potential sources of revenue are as follows:
1) Road Use Tax funds for operations and General Obligation (G.O.) bonds for
capital projects.
2) Road Use Tax funds for operations and special assessments levied against
the benefited areas for capital projects.
3) General property tax levy for both operations and capital.
4) Capital Improvement Revenue fund for capital projects and Road Use Tax
for operations.
5) A stormwater utility for both operations and capital.
Each funding source is further discussed below:
1. Road Use Tax Fund and G.O. Bonds
This alternative would continue to utilize road use taxes for storm sewer
maintenance and engineering which restricts any increases in street maintenance
that are needed. The G.O. Bonds carry a debt service to cover the interest
involved. Based on an annual $600,000 bond issue, the initial interest is 8.30 per
$1,000 valuation. This equates to $5.70 for a $100,000 residential dwelling in the
first year. Of course as the bond issues are made each year the cost increases.
Over a 12 year period, the bonding costs comound to t for the $100 000 re0,80 sidenpcer $Based on twel valuation.
ve
This results in a $48.44 annual cos
year bond issue length, current roll/back, current interest rate, etc., the rate would
stabilize at about 70¢/$1 ,000 or $48.00 per year for a $100,000 residence. This
method of financing has the disadvantage of using a portion of the allowable debt
service. It has the advantage of being flexible in annual bond sales to match
annual needs as approved for project development. No special payment or billing
programs are required.
2. Road Use Tax and Special Assessments
The use of road use tax would continue to restrict street maintenance funds.
Special Assessments levied against those benefited by a specific project would not
involve city-wide cost sharing. The assessment procedure involves assignment of
cost (benefits) based on factors that vary by location. Some of the factors used
include impervious area, elevation, and size of the parcel. This method could
involve litigation based on the citizen/owner perception
sualoly fnvolvessale of G benefits
O
(costs) assigned to each parcel. This funding would
Bonds for construction financing, however repayment would be made through
special assessment payments versus property taxes. Extensive engineering and
legal staff time will be required with this option.
3. General Property Tax Levv
This method would involve reprioritizing the stormwater utility to provide funding for
both operations and capital such that general tax levies would be used for
financing. This could severely limit programs currently funded by the general levy
unless other revenue sources can be identified for them. No special billing
programs would be needed for this option.
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4. Road Use Tax and Capital Reserve Fund
This alternative would continue the Road Use Tax allocation for operations and
establish a Capital Reserve Fund for capital projects. The current State Code
allows the creation of a capital improvement reserve fund for projects such as storm
sewers and stormwater improvements. The capital reserve fund must be approved
by a majority of voters and can raise up to 67'/20 per $1,000 valuation. Based on
the 1994/95 valuation of $960,056,298, an annual fund of $648,000 could be
raised. This would meet the needs of the current capital program proposals. The
advantage of this fund is that it is a pay as you go program and thus does not
decrease the allowable debt service. This option would annually cost the owner of
a $100,000 home a total of$46.17 assuming the current 68.4% rollback.
This capital reserve fund is not affected by the property tax freeze since it requires
an enabling election. No special programs would be needed to develop this
funding option. The levy authorization continues until the City Council votes to
discontinue the levy.
5. Stormwater Utility.
This financing mechanism would create a new user based system that would cover
both operations and capital project costs. The creation of a utility with separate
billings to the owners of area land would involve costs associated with establishing
and updating the database, as well as the accounting work to generate the billing
statement. It is estimated that the administrative costs for setting up a separate
billing system, as well as ongoing system maintenance, are approximately $80,000
to $100,000 annually. If the existing utility billing system could be used, the
administrative costs are estimated to be $50,000 to $75,000.
Several methods are available to spread the costs of operations and capital costs.
They are detailed as follows.-
a) Flat Rate
For$210,000 operations ($95,000 for maintenance; $11,000 for engineering;
and $104,000 for administration) and $600,000 in capital projects, the per
month charge would be $6.14/month per parcel. The calculation is shown
below.-
Cost = $810,000/year _ 11,000 parcels _ 12 months/year
Cost = $6.14 per parcel per month
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b) Land Area
Using the $810,000 needed, the cost for the stormwater system is
apportioned by land area only with no recognition for the type or intensity of
land use. The unit cost for this method is $0.000117962 per square foot per
month. For a 10,000 square foot residential lot, the fee would be $1.18 per
month. For a '/z acre multi-family lot the monthly fee would total $2.57. A
small industrial property of two acres would have a monthly fee of $10.27.
For a large agricultural parcel of 40 acres, the fee grows to $205.54 per
month. This method does not give any recognition to the actual runoff
generated from the land area that is related to size and intensity of
development.
c) Land Area/Runoff Coefficient
In order to relate a utility charge for stormwater to a parcel of property and
establish the rate with respect to the amount of runoff generated by the
parcel, the actual land use must be utilized as well as the land area. The
existing land data base maintained by the City and County Assessors
contained land area information and land use for many of the parcels. This
information was supplemented by Public Works and Planning and Housing
staff to fill in the gaps for the tax exempt parcels and others not originally
included.
Following that process each parcel was assigned to one of the following
classes.-
1. Agricultural/undeveloped
2. Light development - parks, golf courses, cemeteries
3. Residential and 2 family units
4. Multi-family residential - 3+ units
5. Commercial
6. Industrial
Each class was then assigned a runoff coefficient based on typical use of that property.
The runoff coefficient for each land use is then related to the runoff coefficient of the single
family residential lot.
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Land Use Class Coefficient Runoff Unit
1. Agricultural/undeveloped .10 0.25
2. Light development .20 0.50
3. Residential .40 1.00
4. Multi-family residential .70 1.75
5. Commercial .80 2.00
6. Industrial .70 1.75
Using the percentages of land assigned to each class and the runoff units shown above,
a weighted percent of runoff is calculated.
Runoff Weighted Weighted
Use Class % of Land Land Sq.Ft. Unit Land %
1 33.67 192,664,587 .25 48,166,147 9.00
2 10.96 62,714,697 .50 31,357,349 5.86
3 27.68 158,388,945 1.00 158,388,945 29.62
4 2.84 16,250,889 1.75 28,439,056 5.32
5 13.84 79,194,472 2.00 158,388,944 29.62
6 10.99 62,886,362 1.75 110,051,134 20.58
534,791,575
The weighted percentages are then used to calculate a share of the needed stormwater
budget ($810,000).
Weighted
Use Class % Amount Land Area /s .ft.
1 9.00 $ 72,900 192,664,587 $0.000378377
2 5.86 47,466 62,714,697 0.000756856
3 29.62 239,922 158,388,945 0.001514764
4 5.32 43,092 16,250,889 0.002651667
5 29.62 239,922 79,194,472 0.003029529
6 20.58 166,698 62,886,362 0.002650781
Each lot is then multiplied by the appropriate unit corresponding to its use per square foot.
Examples are as follows:
Class 1
40 acre agricultural parcel = $54.94/month
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Class 2
20 acre park parcel = $54.94/month
Class 3
10,000 square foot residential parcel = $1.26/month
Class 4
'/2 acre multi-family parcel = $4.81/month
Class 5
'/ acre commercial parcel = $5.50/month
Class 6
5 acre industrial parcel = $48.11/month
This alternative provides for the allocation of the stormwater costs in a relationship to the
amount of runoff created by the parcel itself. The actual split of costs could be
accomplished in other ways, such as to establish a $3.00 per month minimum with the
remaining funds allocated on the runoff coefficient/land area method. Other cost splits
could be calculated if desired.
A secondary point of discussion is what design standards should be used for any given
area. Up until 1992/93, the storm sewer pipe network was designed with appropriate
capacity to carry the runoff from a 5-year reoccurrence interval rainstorm. This equates
to an event that has a 20% chance of happening in any year. The design and regulations
did not provide facilities to handle any storms above the five-year frequency. Since
1992/93 we have asked developers to cooperate with us in the creation of a grading plan
to address runoff from a 100-year frequency event or one that has a 1% chance of
occurring in any year.
Over the years problem areas have become evident when storm events greater than the
5-year event have created ponding in low points that don't have a "positive" way for the
stormwater to be carried away. These locations are listed in the 1994-1999 CIP. The
appropriate question is what level of storm design should be adopted to address these
problems. In new areas the standard is the 100-year runoff event. Should that also be the
standard for existing areas as well?
One method to establish a policy is to look at an acceptable level of stormwater depth in
the low point and spread of the water across the public right-of-way. Different standards
could be created based on the type of street involved (arterial, collector, local) versus the
private property damage potential. Some ideas will be presented at the February 1st
workshop.
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