Currently the city requires all developments to meet certain minimum detention criteria. Properties that meet such criteria will receive a 25% credit. Properties that meet the minimum city requirements plus achieve additional detention will receive up to an aggregate total of 40% credit for storm water detention. An additional 10% credit can be obtained for water quality measures implemented by the property owner. The minimum storm water service charge shall remain one ERU, even if the credit or credits reduce the ERU multiple below one ERU. The following outlines the criteria for each level of credit.
(A) Minimum detention criteria.
(1) The city currently requires that all new developments meet the following criteria:
(a) Developed discharge not to exceed ten-year pre-developed rate; and
(b) Development must provide reten- tion or detention of 100 years developed rate on site through inline storage, pond or parking lot.
(2) Properties that meet these criteria shall receive a 25% credit. The city shall develop policies and procedures for documenting compliance with the requirements for this credit. If no records are available in the city, the owner shall provide the information to obtain a credit.
(3) All drainage facilities shall be in approved drainage easements before any credit will be allowed. In addition, all drainage facilities shall be maintained by the property owner and verified on annual inspections for the property owner to maintain established credit. Inspections shall be performed annually. In the event of non-compliance, the property owner shall be notified and given 30 to 60 days depending on the severity of the non-compliance to remediate the deficiencies and respond. If such non-compliance has not been remediated by the expiration date of the remediation period given to the property owner, the credit shall be forfeited and the property owner must reapply to obtain a new credit.
(B) Maximum detention criteria.
(1) In addition to the minimum detention credit, a property owner may receive up to an additional 15% credit if the owner’s storm water facilities exceed the city minimum detention requirements in the manner hereinafter described. By increasing capacity on-site, these detention efforts reduce the demand and stress on the downstream drainage facilities.
(2) The city shall credit up to an additional 15% for facilities that meet the following criteria:
Criteria | Credit |
Provide an additional 20% volume storage | 4% |
Provide a reduction in developed peak runoff rate by 20% | 4% |
Provide extended storage with the potential for ground water recharge | 3% |
(3) The city shall develop policies and procedures for documenting compliance with the requirements for the credits described in this § 55.011. If no records are available in the city, the owner shall provide the information to obtain a credit.
(C) Volume credit. Properties that provide additional volume under the emergency spillway of the detention facility shall receive up to an additional 4% credit. To receive this credit, the applicant must provide the calculations and data necessary to quantify the additional storage volume. The credit is calculated by determining the minimum detention volume required by the city and comparing it to the volume provided. The additional credit shall be calculated based on the following table:
Table 55.011C (Credit) - Volume Credit | |
Additional Volume Provided | % Credit |
20% or greater | 4% |
15-20% | 3% |
10-15% | 2% |
5-10% | 1% |
0-5% | 0% |
(D) Peak reduction credit.
(1) Properties that provide additional decrease in peak flow rate shall receive up to an additional 4% credit.
(2) The credit is calculated by determining the required peak outflow to meet the city requirements, and comparing it to the designed peak outflow.
(3) The additional credit shall be calculated based on the following table:
Table 55.011D - Peak Reduction Credit | |
Additional Reduction in Peak | % Credit |
20% or greater | 4% |
15-20% | 3% |
10-15% | 2% |
5-10% | 1% |
0-5% | 0% |
(E) Extended storage credit. Properties that provide extended storage greater than 24 hours will receive up to 3% additional credit. The credit will be calculated by determining the time it takes the pond to drain, from its peak elevation, to the original time to peak of the undeveloped conditions. The additional credit percentage will be determined by the following table:
Table 55.011(E) - Extended Storage Credit | |
Detention Time Provided | % Credit |
24 hours or greater | 3% |
16-24 hours | 2% |
8-16 hours | 1% |
0-8 hours | 0% |
(F) Water quality credit. Properties that provide measures that improve the quality of storm water that leaves the property will receive up to an additional 10% above the maximum 40% for storm water quantity. This credit can apply to property owners who are required to maintain individual NPDES industrial permits. All applicants for the water quality credit will be required to provide copies of past site compliance evaluations and most current site compliance evaluations to maintain this credit. The city shall develop policies and procedures to establish standards for the granting of the water quality credit.
(G) Payment required. Application for any one or more credits, or any appeal of the determination or determinations made in respect thereto shall not constitute a valid reason for non-payment by the user of the originally assessed storm water service charge.
(H) Appeals. Determinations regarding credits for a user may be appealed in the same manner as will be established by the city for appeals of ERU determinations pursuant to § 55.010.
(I) Inspections. Any party requesting a credit shall permit the city and its agents, to undertake any inspection or inspections needed, in the discretion of the city, to determine whether any one or more credits are appropriate. The city further reserves the right to inspect periodically all storm drainage control facilities of a user that has received one or more credits to ascertain whether such facilities are operating properly. If such facilities, due to improper maintenance or any other reason, fails to meet the criteria required for any credit, the city shall issue an order to complete the repairs of such facilities within 60 days. If such repairs are not completed within the 60-day period, the city, in its sole discretion, may issue an order eliminating or reducing detention credits to an appropriate level. Any such facility shall not be eligible to reapply for credit adjustments for a period of 12 months following any credit reduction or elimination ordered by the city.
(J) Land alteration. The issuance of any building permit or other action which results in land alteration with respect to a property receiving any one or more credits under this section shall be cause for an adjustment, as appropriate, of the credits to which the owner may be entitled. The property owner shall have the obligation of informing the city of any such changes in the manner prescribed.
(Prior Code, § 59.11)