A. Purpose: The purpose of this section is to regulate the installation of impervious surfaces within the city of Holladay. It is the intent of this regulation to be sensitive to the natural and built environment. The city's intent is to support reasonable land use regulations. Some of the tools that can be used in this regard are included elsewhere in this title and also outlined below. The restriction of impervious surfaces can have a positive effect on the overall environment. Impervious surfaces replace and alter the natural landscape. Their construction can initiate a chain of events that modifies water resources, urban air elements, and the overall environment.
Findings supporting this regulation are:
1. Impervious surfaces seal the soil surface, eliminating the benefits of rainwater filtration and natural groundwater recharge. Stormwaters run across impervious surfaces, collecting toxins and debris which may be damaging to the health of riparian habitats and to all waterways and lakes.
2. Excessive storm drainage created by uncontrolled runoff often negatively impacts private property and public infrastructure.
3. Impervious surfaces damage tree roots systems depriving them of water which in turn destroys the canopy and shade that would otherwise moderate excessively hot urban climates known as "heat islands". Impervious surfaces displace living vegetation, which is necessary for normal atmospheric carbon cycling.
4. The loss of urban forests, especially in arid Utah and particularly in Holladay, which is well known for its spectacular tree cover, results in a loss of community identity and reduces property values.
5. In areas of urban build out, redevelopment and reconstruction are opportunities for environmental rehabilitation. Permeable or porous paving is an important component in low impact development.
B. Maximum Lot Coverage: The total allowable lot coverage for all structures and the total impervious coverage for any lot is shown on chart 13.14.080B of this section, excluding outdoor swimming pools, ponds with artificial liners and other water features. Approved permeable or porous surfaces may be allowed per coverage bonus table 13.14.080C of this section.
Lot Size In Square Feet | Percent Coverage Of All Structures | Percent Impervious Coverage |
Lot Size In Square Feet | Percent Coverage Of All Structures | Percent Impervious Coverage |
Less than 10,000 | 35 | 40 |
10,001 to 15,000 | 31 | 36 |
15,001 to 20,000 | 28 | 33 |
20,001 to 30,000 | 25 | 30 |
30,001 to 40,000 | 24 | 29 |
40,001 to 50,000 | 23 | 28 |
50,001 to 60,000 | 22 | 27 |
60,001 to 70,000 | 21 | 26 |
Above 70,000 | 20 | 25 |
C. Coverage Bonus: Total percent impervious coverage, as per chart 13.14.080B of this section, may be increased no more than an additional ten percent (10%) as per coverage bonus table 13.14.080C of this section. This provision may not be used to increase the maximum percent coverage of all structures as set forth herein.
Method | Maximum Percent Increase |
Plant 2 inch caliper tree: 1 percent per tree. Species as per tree selection guide made available through city of Holladay community development department | 6.0 percent |
Permeable pavers or porous surface1: Installed as per approved manufacturing standards | 3.5 percent |
Water wise landscaping: Landscaping area must be equal in area to the percent increase gained, as per Holladay water wise guidelines made available through city of Holladay community development department | 3.5 percent |
Sump2 | 2.5 percent |
Cistern2 | 2.5 percent |
Notes:
1. Appropriate porosity approved by city engineer.
2. Size, design and capacity approved by city engineer.
(Ord. 2012-15, 9-20-2012)