E-3 C15-2021-0085 GRANTED DS W/CONDS AND RAINWATER INFO — original pdf

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CITY OF AUSTIN Board of Adjustment Decision Sheet E-3 DATE: Monday November 8, 2021 CASE NUMBER: C15-2021-0085 ___Y____Thomas Ates ___Y____Brooke Bailey ___Y____Jessica Cohen ___Y____Melissa Hawthorne ___Y____Barbara Mcarthur ___Y____Rahm McDaniel ___Y____Darryl Pruett ___Y____Agustina Rodriguez ___Y____Richard Smith ___-____Michael Von Ohlen (out) ___-____Nicholl Wade (out) ___Y____Kelly Blume (Alternate) ___Y____Carrie Waller (Alternate) ___-____Vacant (Alternate) APPLICANT: David Cancialosi OWNER: Estates at Lake Austin, LP ADDRESS: 1717 CHANNEL RD VARIANCE REQUESTED: The applicant is requesting variance(s) from the Land Development Code, Section 25-2-551 (Lake Austin District Regulations) (B) (1) (a) from shoreline setback requirements to reduce the shoreline setback from 75 feet (required) to 25 feet (requested) along a man-made inlet in order to erect a Single-Family + associated improvements in a “LA”, Lake Austin zoning district. BOARD’S DECISION: BOA MEETING SEPT 13, 2021 The public hearing was closed by Chair Jessica Cohen, Board Member Michael Von Ohlen motions to Postpone to October 11, 2021; Board Member Rahm McDaniel seconds on a 11-0 vote; POSTPONED TO OCTOBER 11, 2021; Oct 11, 2021-POSTPONED TO NOVEMBER 8, 2021 BY BOARD MEMBERS (Due to not enough Board Members present at the meeting); Nov 8, 2021 The public hearing was closed by Madam Chair Jessica Cohen, Madam Chair Jessica Cohen motions to approve with conditions to install a rainwater system and to limit the impervious cover to 32%; Board Member Darryl Pruett seconds on a 11-0 vote; GRANTED WITH CONDITIONS TO INSTALL A RAINWATER SYSTEM AND TO LIMIT THE IMPERVIOUS COVER TO 32%. FINDING: 1. The Zoning regulations applicable to the property do not allow for a reasonable use because: the zoning regulations combined with unique hardships prevent a reasonable use of this site as prescribed by the applicable zoning district. 2. (a) The hardship for which the variance is requested is unique to the property in that: the number of hardships and the extent to which they encumber the site severely limit the normal development typically found on a lot of this size in LA zoning (b) The hardship is not general to the area in which the property is located because: man made sloughs create significant development constraints because of the 75’ shoreline setback 3. The variance will not alter the character of the area adjacent to the property, will not impair the use of adjacent conforming property, and will not impair the purpose of the regulations of the zoning district in which the property is located because: any new construction will be in keeping the varied construction styles found along LA, there will be no adverse impact to adjacent properties, all development shall comply with all other applicable codes. ______________________________ Elaine Ramirez Executive Liaison ____________________________ Jessica Cohen Madam Chair Rainwater Harvesting Compensation for excess impervious cover (IC) Required: 1. Rain tank 2.6 times greater in gallons than number of square feet in excess of IC limit This formula calculates the number of gallons required to provide flood mitigation plus a factor of safety Example: 5,000 sq.ft. lot with 45% IC limit permitted by Code is granted a variance to build 46% IC Therefore: 5,000 x 0.45 = 2,250 sq.ft. (Code) vs. 5,000 x 46% = 2,300 sq.ft. (allowed by variance) Therefore: 2,300 - 2,250 = 50 sq.ft. over Code limit Therefore: 50 sq.ft. over limit x 2.6 = 130 gallon rain tank required (minimum) Result: Applicant installs a 150-gallon rain tank or two 75-gallon rain barrels 2. Guttering installed on an area of roof in square feet at least as large as the number of gallons of the rain tank Example: Applicant ensures that roof area draining at least 150 sq.ft. drains via gutters to the 150-gallon tank Or two separate areas draining at least 75 sq.ft. each drain to rain gutters to the two rain barrels. 3. Outflow from tank directed to a safe drainage conveyance where won't adversely imact neighboring properties Calculation Table Impervious Cover sq.ft. overage 50 100 200 300 400 500 600 700 800 900 1,000 2,000 3,000 4,000 5,000 Minimum Gallons of Rain Tank Volume Required 130 260 520 780 1,040 1,300 1,560 1,820 2,080 2,340 2,600 5,200 7,800 10,400 13,000 RWH Calculation Table Created: October 2017