Item 6H PresentationItem 6H
Amendments to Ordinance No. 480 to add
regulations for streamway buffer and
permeable pavement (Ord. 480 -VVVV)
Sustainability Plan
•Adopted in 2014 (Ord. No. 1104)
•Part of City’s Comprehensive
Plan, Southlake 2030.
•Contains prioritized
recommendations to maximize
efficient use of public resources.
Background
Citizens Survey Strategy Map Southlake 2030 Plan
Proposed Amendment to Ord. No. 480
•INCENTIVIZED OPTION: Permeable
Concrete and Asphalt may be used
to offset stormwater utility fees.
•Definition added for permeable
pavement.
•Permeable pavers may be approved
on a case by case basis.
•Soil infiltration of 0.5 in/hr or greater
is required, per iSWM specifications.
Proposed Amendment to Ord. No. 480
•REQUIRED OPTION: 20% of all off-
street parking areas required to be
permeable on sites or developments
that are larger than 1 acre.
•Permeable pavers may be approved
on a case by case basis.
•Ordinance may be revisited in the
future to consider adjusting
percentage.
Proposed Amendment to Ord. No. 480
•HYBRID OPTION: 20% of all off-
street parking areas required to be
permeable on sites or developments
that are larger than 1 acre.
•Any use of permeable pavement
above base required amount qualifies
for incentive.
•Added requirement to use matching
materials for use of permeable and
conventional pavement
Benefits of Permeable
Pavement:
•Reduces stormwater runoff
and “first flush” pollution;
•Allows rainfall to percolate
into soil rather than sheet
flowing into waterways;
Source: Sustainability Master Plan, pg. 18
•Reduces surface
temperatures by absorbing
more heat than impervious
paving;
•Reduces pooling of water
during rain events
Permeable vs. Conventional Surfaces
Surface Cost Per Sq Ft Installed*
Conventional Concrete $1.44 to $10.06
Permeable Concrete $2.00 to $14.00
(28-30% higher for permeable)
Conventional Asphalt $0.46 to $7.40
Permeable Asphalt $0.50 to $8.11
(9-10% higher for permeable)
Permeable Pavers $5.00 to $17.86
(45-70% higher than std concrete)
* Installed costs accounts for associated drainage structures and base aggregate costs,
but does not account for maintenance or any land value factors.
Permeable vs. Conventional Surfaces
Surface Cost Per Sq Ft Installed*
Conventional Concrete $1.44 to $10.06
Permeable Concrete $2.00 to $14.00
(28-30% higher for permeable)
Conventional Asphalt $0.46 to $7.40
Permeable Asphalt $0.50 to $8.11
(9-10% higher for permeable)
Permeable Pavers $5.00 to $17.86
(45-70% higher than std concrete)
* Installed costs accounts for associated drainage structures and base aggregate costs,
but does not account for maintenance or any land value factors.
•Consider incentivizing or requiring use of pervious pavement
Amendment Details – Permeable Pavement
Sustainability Master Plan
Proposed Amendment to Ord. No. 480
Amendment Details – Creek Buffer
•A Tier 1 recommendation of the 2015 Sustainability
Master Plan is the implementation of a stream/creek/
floodplain buffer.
•The intention of the buffer is to reduce erosion,
preserve habitat, increase open space, and minimize
impacts from site development and increases in
impervious coverage.
Benefits of Creek Buffer
•Can be used as
nonstructural stormwater
filtering and infiltration zones;
•Keeps structures out of the
floodplain and provides a
right-of-way for large flood
events;
Benefits of Creek Buffer
•Helps to preserve riparian
ecosystems and habitats.
(From iSWM Technical Manual, rev. 9/14)
Sustainability Master Plan – Water Resources
“(S)imply providing a buffer area adjacent to
streams, creeks, and floodplains can protect
water quality by allowing the ecosystem to
naturally collect and treat pollutants in runoff
before they reach surface waters. Buffer areas
can also reduce erosion, preserve habitat,
increase open space, and reduce flooding.”
- Pg. 18
Sustainability Master Plan – Goals and Objectives
Sustainability Master Plan – Built and Natural Environment
Pg. 39
Sustainability Master Plan
Water Resources Recommendations
iSWM
•The adopted Integrated
Stormwater Management
(iSWM) Manual assists cities
in meeting TCEQ
stormwater requirements, in
part by preserving certain
natural site features
conducive to abatement.
iSWM
•Preservation and
conservation of existing
stream and riparian areas
within a site listed as
“Integrated Site Design
Practice”s in the iSWM
Technical Manual.
Sustainability Master Plan
Water Resources Recommendations
Typical Creek Buffer Profile
(From iSWM Technical Manual, rev. 9/14)
Proposed Amendment to Ord. No. 480
•Allow bufferyard credit on property
boundary containing buffer or on
boundaries parallel to the buffer
•Allow 1 for 1 tree credit for saving
native trees within the buffer
•Area measured 25ft from top of bank
or 50ft from the creek centerline
•No disturbance within stream buffer
except for uses allowed in bufferyards
STREAM ON PROPERTY BOUNDARY
Saving trees in buffer could allow for
reduction in tree planting requirements.
Off-street parking
Building
STREAM INTERIOR TO SITE
Width and planting credit allowed for bufferyards parallel to stream corridor
•Section 4 and Section 34 do not agree on number of garage
sales allowed
Amendment Details – Garage Sales
•Section 4 and Section 34 do not agree on number of garage
sales allowed
Amendment Details – Garage Sales
Option 1 – Amend Section 4
GARAGE SALES – Occasional sales (garage sales and patio sales only) at retail,
not to exceed two (2) three (3) in number on the same premises in any one
calendar year, by a person who does not hold himself out as engaging in, or does
not habitually engage in, the business of selling such property at retail; provided
that (1) the sale shall be confined to the garage and/or patio of the premises; (2) no
new merchandise acquired solely for the purpose of resale on the premises shall
be sold at such occasional sale; (3) the duration of each such sale shall not exceed
three (3) consecutive calendar days; (4) a permit shall be secured at least 72 hours
prior to and shall be prominently posted on such premises during such sale; (5) the
permit fee amount shall be as established by the City Council; (6) only one sign
shall be permitted, not to exceed two (2) square feet in area, upon the premises
where and when the sale is taking place. All other signs relating to the sale, either
on or off the premises, shall meet the requirements of all sign regulations adopted
by the City.
Option 2 - Amend Section 34
ACCESSORY USE District Where
Permitted
aa. Yard or garage sales, subject to the following requirements:
1)No more than 3 2 garage sales within any 12 month period may occur.
2)The duration of the sale shall not exceed 72 hours.
(As amended by Ord. No. 480-UUUU)
AG, RE-5, RE-7,
RCS, SF-1A, SF-
1B, SF-2, SF-20A,
SF-20B, SF-30,
MF-1, MF-2, TZD*,
EC*
Proposed Amendment to Section 45 to add “RE-5”
and “RE-7” in place of former “RE” district
SPECIFIC USE PERMIT
District Where
Permitted
43. Accessory buildings located in the front yard. SF-1A, SF-1B and
RE, RE-5 and RE-7
PLOT PLAN
REQUIRED
50. Electric vehicle charging space(s)
•Level 1, Level 2, or Level 3/Rapid Charge for commercial or public
use.
Subject to the requirements set forth in Section 45.20 of this ordinance.
All except AG, RE
RE-5, RE-7, RCS,
SF-1A, SF-1B, SF-
2, SF-20A, SF-20B,
SF-30, MH, MF-1
PZ Action
August 18, 2016; Voted 4-0 to recommend approval,
noting that both options for the paving will go to Council,
further noting P&Z's recommendation with respect to
the number of garage sales allowed within section 4,
Definitions and section 34, Accessory Uses be two
allowed per year and not three, and approving the final
component of the amendment.
CC 1st Reading
October 4, 2016; Approved 4-0, noting that the recommendation of
mandatory versus incentivized use of permeable material, Council is
not making a recommendation rather is directing staff to provide
options and clarity at 2nd reading as it relates to no requirement with
incentives, a requirement plus incentives and any new options to
address concerns regarding the feasibility of implementing the
process. Also noting that in terms of garage sales, Council is allowing
a maximum of two (2) per year per address and specifically noting
that all other changes proposed in this ordinance are approved at 1st
reading. Also noting that related to the creek setback regulations that
it will be the greater of 25 feet or 50 from the centerline of the creek.
Questions?