13A ACTION - Laserfiche WebLink

Home

City of San Leandro Stormwater Fee Report Final Report 3. Rate Structure Analysis HF&H Consultants, LLC Page 7 March 12, 2024 3. RATE STRUCTURE ANALYSIS Proposition 218 states that the amount of a fee upon any parcel shall not exceed the proportional costs of the service attributable to the parcel. The use of the City’s stormwater system that is attributed to each parcel must be proportionate to the estimated amount of stormwater runoff contributed by the parcel, which is, in turn, proportionate to the amount of impervious surface area on a parcel (such as building roofs and pavements). SINGLE-FAMILY RESIDENTIAL PARCELS The most widely used method of establishing storm drainage rates is to use the average Single-Family Residential parcel (SFR) as the basic unit of measure, which is called the Single Family Equivalent (SFE). The metric for this fee structure is impervious surface area, a benchmark amount of impervious surface area must be established for the average single-family residential property. The City has a wide range of sizes of SFR parcels, which have varying percentages of impervious area. Generally, smaller, denser parcels tend to have a higher proportion of impervious area than larger, less dense parcels, which tend to have a lower percentage of impervious area, as larger residential properties tend to have a larger proportion of pervious landscaping, and therefore a smaller proportion of impervious area. The City has a large range of sizes of SFR parcels; therefore, the range of SFR was broken into three size categories as shown in Table 3 below with the medium category containing the largest number of parcels. A random sample of 484 parcels in that size category was selected, and the Impervious Surface Area (ISA) (e.g., concrete, asphalt, roofs, pavers) of each sample parcel was measured using aerial photographs. The average ISA is 3,069 square feet, which will be used as the benchmark for all other size categories and other non-residential land uses. Therefore, for subsequent calculations for all non-medium sizes Single- Family parcels, 1 SFE equals 3,044 square feet of Impervious Surface Areas). Table 3 – Summary of Single-Family Parcels 1 As calculated in Table 5 2 Single-Family Equivalent as compared to the Median Impervious Surface Area of Medium Size SFR parcels NON-SINGLE FAMILY RESIDENTIAL PARCELS Unlike residential parcels, non-single family parcels can vary widely in size (e.g., anywhere from 0.08 acres to 100+ acres), as wells as impervious characteristics (e.g., parcels with commercial offices tend to have a high percentage of impervious surfaces from office buildings and parking lots, while parks tend to have a lower percentage of impervious surfaces from significant landscaped areas, while multi-family complexes fall somewhere in between). For this reason, the parcels have been grouped into land use categories Single-Family Residential (SFR) Parcel Sizes Parcel Size Range (square footage) # of Parcels % of SFR Parcels Average Impervious Surface Area1 SFE2 per Parcel Small < 3,200 1,193 6%1,602 0.52 Medium 3,200 to 7,200 16,111 79%3,067 1.00 Large > 7,200 3,094 15%4,617 1.51 20,398 100%9,287