HDR Engineering Inc. 1/18/2022 Amendment 1

surface unit(ISU)must be established. Once the ISU is defined,then the number of commercial ISU billing units can be established. ✓ Design of Stormwater Rate Alternatives—With the billing information above, HDR can design the stormwater rates for residential and non-residential. The residential rates to be designed will be similar to the City's current stormwater rate(i.e.,a flat rate). HDR will develop a uniform residential flat rate and a two-part large/small parcel flat rate. For the non-commercial rates,the 2018 impervious surface rate analysis reviewed two options;a$/square foot of impervious area and an approach based upon the relationship of lot size and impervious area (%range). The two methods produced similar results and a specific option was not selected as the preferred option. If the City still does not have a preferred non-residential stormwater rate structure then HDR will develop both rate structures for the City's review and consideration. Bill comparisons similar to those developed as a part of the 2018 stormwater rate structure study will be developed as a part of this analysis. V Rate Transition—HDR and the City recognize the challenges and customer bill impacts of moving from the current non-residential stormwater rate structures to an impervious approach. Given that, this study will review the possible methods of rate transition to gradually move non-residential to full,cost-based, impervious stormwater rates. HDR will collaborate with City staff on the overall billing/rate setting approach. However,the City will be responsible for the ultimate billing approach that works within the City's billing system.Working with the City, HDR will develop a rate transition plan for the new non-residential stormwater rates. During the previous study(2016)the City reviewed the issue of stormwater credits.As part of this task, HDR will review the prior information provided to the City on the approach for stormwater credits. Task 1 Assumptions: Develop an Excel model to review and sort the stormwater parcel data (City is responsible for reviewing and assembling data). • Develop alternative stormwater rate designs;residential and non-residential and bill comparisons. Task 1 Deliverables: ® Proposed stormwater rates and bill comparisons. Task 2:Rate Study Documentation—Written Report(Original Task) Prepare/submit a study report summarizing assumptions,findings, and study recommendations for each utility.The supporting spreadsheet analyses for each utility will be included as technical appendices. Develop an electronic(PDF)draft final report and incorporate any City comments or corrections into the final electronic(PDF)written report. This task has been substantially completed at this time and will be provided to the City for review and a final report developed based on City review comments and edits. Task 2 Assumptions: to An electronic draft report will be provided to City staff for review and comments. Task 2 Deliverables: • A final electronic report which includes a technical appendices of the analyses completed. Task 3—Value Assessment of Utilities Structures(Original and Updated Task) As part of the study,the City is interested in determining the value of above ground assets for assisting in reviewing insurance requirements. This task will provide a high level review of the above ground