ORD-2025-01 Development Code Effective January 25, 2025

6 CHAPTER

Environmental Regulations

B. Stream Protection Volume (SPV). Stream Protection Volume is based on the amount of runoff produced over the developed area from the listed rainfall amount identified in Section 6.1.4.1 (D). 1. SPV 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. C. Stormwater Quality Treatment. Required stormwater quality treatment levels for different locations are listed in the table below and represents the percent reduction in the increased total suspended solids load.

D. Stream Protection Volume and Stormwater Treatment Level Table

Table 6.1 Stream Protection Volume and Stormwater treatment level table

Stormwater Treatment Level

SPV amount Design Rainfall

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

s Dr

Aquarena Spring

D r

m

o

s

e s

S

W

N Guadalupe St

W

W

o n

d e

s S t

r W o r l d D r

E H o p k i n

S Guadalupe St S LBJ Dr

W Hopkins St

FM 1984

H w y

Wonder World Dr

ro p

ld B a s t

¬« 80

O

§¨¦ 35

Rd

Hunter

W M c C a r t y

L n

Clovis Barker Rd

San Marcos River Protection Zone San Marcos River Corridor

Edwards Aquifer Recharge Zone Edwards Aquifer Transition Zone Edwards Aquifer Contributing Zone within the Transition Zone

E McCarty Ln

Redwood Rd

¬« 123

St

a

ples Rd

Stormwater Management District

0

1,250

2,500

5,000

7,500

Feet N

S Old Bastrop Hwy

6:7

Amended: January 21, 2025 San Marcos Development Code