What Lennar/Wong Tract is Building
~9,315 LF along FM 812
Lennar's Wong Tract (123.5 ac at 10449 FM 812) received SER-5002 approval in April 2025 for a 16-inch water main running along FM 812 — passing directly adjacent to BBM's 10209 FM 812 property. This is a regional-capacity main, significantly oversized for Wong Tract alone.
✅ BBM impact: Eliminates need to build standalone water extension. Tap/lateral connection only (~$50–150K vs. $1–3M+ for full extension).
Gravity interceptor + 1,650 GPM lift station + force main
Lennar's SER-5003 (wastewater) calls for a 24-inch gravity interceptor running along FM 973 and FM 812, with a 1,650 GPM lift station. The interceptor is sized at 4× Wong Tract's minimum needs — clearly a regional trunk line intended to serve the entire FM 812 corridor per Austin Water's master plan.
✅ BBM impact: Lift station has 3× excess capacity. BBM can tie in via a tap and force main connection vs. building a full independent wastewater system.
Why this matters for BBM: The SIR analysis previously modeled $2–6M+ for utility extensions at 10209 FM 812. With Lennar building the 16" water main and 24" wastewater interceptor directly along FM 812, BBM's actual utility cost may be dramatically lower — potentially just a tap connection and short lateral. The key unknowns are: (1) exact tap point location relative to BBM's property line, (2) whether Austin Water will allow a tap at this stage, and (3) the tap fee schedule.
LUE Summary — BBM 10209 FM 812
218.1
Total LUEs
400
MF Units (planned)
30K SF
Retail Component
20.18 ac
Total Site Area
LUE methodology: 218.1 LUEs based on 400 MF units (at ~0.45 LUE/unit) + 30K SF retail (~30 LUEs). Austin Water ETJ service requires SER approval (Service Extension Request) before any development permits. BBM's SER applications for water and wastewater have been filed. Approval triggers the right to connect to the Austin Water system — and in this case, to tap the Lennar/Wong infrastructure running adjacent to the site.
Tap Cost vs. Standalone Extension — Estimated Ranges
| Scenario | Water Cost | Wastewater Cost | Total Range | Notes |
|---|---|---|---|---|
| Standalone Extension Without Lennar infra |
$1.5–$3M | $1.5–$3M+ | $3M–$6M+ | Estimated from SIR analysis. Requires independently building trunk lines to existing Austin Water grid — expensive and time-consuming. |
| Tap Into Lennar Infra With Wong Tract as-built |
$75–$200K | $100–$300K | $175K–$500K | Tap + lateral connection to Lennar's 16" water main and 24" WW interceptor. Significantly lower cost basis. Verify tap fee schedule with Austin Water. |
| Austin Water Tap Fees Per LUE (218.1 total) |
~$3–5K/LUE (water) | ~$4–7K/LUE (WW) | $1.5M–$2.6M | Impact fees separate from infrastructure cost. Austin Water ETJ tap fees are substantial but predictable. Verify current rate schedule with Mahoney. |
Note: Cost ranges are estimates based on typical Austin Water ETJ construction costs. Actual costs depend on tap point location, line depth, distance, and Austin Water's current fee schedule. Mahoney Engineering to confirm during today's call.
Austin Water ETJ Implications
💧 SER Approval Required Before Any Development
Austin Water requires a Service Extension Request (SER) for any property in the ETJ connecting to the Austin Water system. BBM filed SER applications for both water and wastewater. SER approval is a prerequisite to plat recordation and development permits — a critical feasibility milestone.
🏗️ Lennar's Build Changes the SER Economics
Pre-Lennar: BBM's SER would need to account for the full infrastructure extension cost. Post-Lennar (once 16" water main and 24" WW interceptor are in the ground): BBM's SER should only require a tap and lateral — dramatically improving project economics and reducing the infrastructure risk to feasibility.
⚠️ TxDOT ROW Is Still Unknown — Key Risk
TxDOT's ROW acquisition for FM 812 widening began mid-2025 per their project page. The exact ROW take along BBM's 10209 FM 812 frontage is unknown. This could affect both the site area and utility tap locations. Must confirm with Mahoney and TxDOT today.
3 Questions for Mahoney — Today at 2pm
1
Where exactly does Lennar's 16" water main and 24" wastewater interceptor pass relative to our property line at 10209 FM 812 — and has Austin Water confirmed we can tap in?
We need to know the exact tap point location and whether Austin Water has indicated willingness to allow BBM to connect to the Wong Tract infrastructure. Mahoney may have discussed this with Austin Water during the SER process. Get the tap fee schedule from Austin Water if available.
2
What is TxDOT's expected ROW take on FM 812 along our frontage — and how does the $145M FM 812 widening project (US 183 to SH 21) affect our site plan, driveway access, and utility easements?
TxDOT is widening FM 812 to 4 lanes. ROW acquisition started mid-2025. The 10209 FM 812 site likely has frontage that will be impacted. How many feet of ROW? Does it affect our planned retail pads along FM 812? Driveway spacing? Utility easements along the frontage?
3
Is the current concept plan (400 MF units + 30K SF retail, 218.1 LUEs) still achievable given the TxDOT ROW uncertainty and the 2-driveway constraint from TxDOT/Austin — and what is the revised timeline to SER approval?
We need to validate that the development program is still viable and that the SER approval timeline fits our feasibility period. If TxDOT takes significant ROW, does our 400-unit MF program need to shrink? What is Mahoney's current estimate for SER approval — and what are the critical path items?