San Marcos Development Code 9.1.2020

6 C H A P T E R

Environmental Regulations

1. WQV shall be retained or detained on-site. Drawdown time shall be 48-hours. 2. The 90th percentile rainfall event for San Marcos is 1.6 inches 3. The 85th percentile rainfall event for San Marcos is 1.25 inches. B. Water Quality Volume Treatment. Required water quality volume treatment level for different locations is listed in the table below and represents the percent reduction in the increased total suspeneded solids load.

C. Water Quality Volume and Treatment Level Table

Table 6.1 water Quality Volume and treatment level table

WQV amount Design Rainfall

WQV Treatment Level

Location

Edwards Aquifer Recharge Zone Edwards Aquifer Transition Zone and Contributing Zone within the Transition Zone San Marcos River Protection Zone

1.60”

89%

1.25”

85%

1.25”

80%

San Marcos River Corridor

1.60”

89%

Figure 6.2 Environmental Protection zones

¬ « 21

O l d R a n c h R o a d 12

N LBJ Dr

Aquarena Spring s Dr

W S e s s o m D r

N Guadalupe St

W W o n d e r W o r l d D r

E H o p k i n s S t

S Guadalupe St S LBJ Dr

W Hopkins St

FM 1984

O ld B a s t r o p H w y

WonderWorld Dr

¬ « 80

§ ¨ ¦ 35

Hunter Rd

W M c C a r t y L n

Clovis Barker Rd

San Marcos River Protection Zone San Marcos River Corridor

EdwardsAquiferRechargeZone EdwardsAquiferTransitionZone EdwardsAquiferContributingZonewithin theTransitionZone

E McCarty Ln

Redwood Rd

¬ « 123

St a ples Rd

Stormwater Management District

0

1,250

2,500

5,000

7,500

N

S Old Bastrop Hwy

Feet

6:7

Amended: September 1, 2020 San Marcos Development Code