Home > Analysis: 3205 Thornwood Dr, Pasadena, TX 77503 09/29/2025

📊 Environmental Assessment Report

This comprehensive report analyzes both flood risk and industrial pollution exposure for this property. The assessment combines multiple data sources including USGS elevation, FEMA flood zones, historical storm modeling, and EPA Toxic Release Inventory records.

🌊 Part 1: Flood Risk Analysis

Property Overview

This section shows the fundamental characteristics of the property, including its elevation above sea level, FEMA flood zone designation, and our calculated overall flood risk rating based on historical data and topographic analysis.

Address

3205 THORNWOOD DR PASADENA 77503

Building Size

1,623 sqft

Total structure area from HCAD building records.

Elevation

31.1 ft

Height above sea level from USGS data.

FEMA Flood Zone

Moderate to Low Risk - Outside 500-year floodplain

Overall Risk

Very Low

Risk based on FEMA zone and simulation.

Risk Assessment Outputs

These detailed metrics show the technical outputs from our flood risk model. They include predicted water depths at the property during a 5000-year flood event and estimated flood damage based on USACE methodology.

Risk Rating

Very Low

Flood Depth

0 ft ±0.5 ft

No flooding at current water level.

Water Surface Elevation (WSE)

N/A

Water surface elevation data not available.

Area Inundated

N/A

Data not available

Nearest Bayou Stage

N/A

No nearby bayou within monitoring range

Depth-Damage Estimate (HCAD Valuation)

Property not flooded at current water level. No damage to calculate.

Depth-Damage Estimate (Neighborhood Comparison)

Property not flooded at current water level. No damage to calculate.

Analysis Method

COG Bathtub Model

Raster-based flood inundation query

Flood Simulation

This simulation shows whether the property would flood based on a 5000-year flood event with 3m (9.84ft) water level. Use the interactive tool to explore different scenarios.

✅ Property Would Be Safe

Safety Margin: 21.1 feet
Severity: Safe

Adjust Flood Simulation

The analysis above uses default settings (5000-year flood, 3m/9.84ft water level). To explore different flood scenarios with interactive maps, return to the main tool:

Open Interactive Analysis Tool

Flood Risk Recommendations

Based on the property's flood risk profile, here are specific action items to consider.

FEMA Zone X (minimal hazard) - flood insurance available at preferred rates.
Review the interactive flood simulator to understand how different rainfall events could affect this property.
Contact Harris County Flood Control District (HCFCD) for drainage projects and flood information.

🏭 Part 2: Industrial Pollution Exposure

Property Pollution Ranking

High

Higher pollution than 79% of Houston homes

This ranking compares pollution levels within 2 miles of this property against 10,000 randomly sampled Houston metro properties. Lower percentiles indicate higher pollution exposure.

Industrial Pollution Nearby (Last 10 Years)

695 thousand lbs

Extremely High

106.5x more than typical Houston property
≈ 35 dump trucks of chemicals within 2 miles

Total chemical releases from all industrial facilities within a 2-mile radius over the past decade (2014–2024). Data from EPA's Toxic Release Inventory tracking air, water, and land discharges.

💨 Air Pollution (Last 10 Years)

694 thousand lbs

Extremely High

144.0x more than typical Houston property

Chemicals released into the air from nearby facilities over 10 years. Includes both fugitive emissions (leaks, evaporation) and stack emissions (smokestacks, vents). May affect local air quality.

💧 Water Pollution (Last 10 Years)

527 lbs

High

Chemical discharges to surface water (bayous, streams, drainage) from industrial facilities within 2 miles over the past decade. May impact local waterways and drainage systems.

❤️ Why It Matters

High chemical activity nearby can indicate industrial zones, truck traffic, or potential odor and noise issues. These factors may affect air quality, long-term property desirability, and neighborhood character. This data helps you understand the industrial footprint around your property.

🏙️ Houston Metro Benchmarks

Comparison with typical Houston properties (based on 10,000 randomly sampled homes). All measurements are for chemicals released within a 2-mile radius.

Period	Total	Air	Water
Typical Houston Property (2014-2024)	6,524 lbs	4,822 lbs	0 lbs
This Property (2014-2024)	695,040 lbs	694,482 lbs	527 lbs
Typical Houston Property (2024 Only)	2 lbs	1 lbs	0 lbs
This Property (2024 Only)	130,885 lbs	87,502 lbs	19 lbs

📊 How This Property Compares to Houston Metro

Based on a random sample of 10,000 Houston properties, this chart shows the distribution of pollution levels across the metro area. The highlighted bar indicates where this property falls compared to other homes. Lower percentiles mean higher pollution exposure.

0-9thMost Polluted

9.9%

10-19th

10.1%

20-29th

9.9%

30-39th

10.1%

40-49th

9.7%

50-59th

10.2%

60-69th

70-79th

5.8%

80-89th

4.3%

90-100thLowest Pollution

34.2%

Higher pollution than 79% of Houston homes

Each bar's width represents the percentage of Houston homes in that pollution range. This property ranks in the 20-29th percentile (top 25% most polluted).

Top chemicals released near this property (past 10 years):

Methanol, Ammonia, Vinyl acetate, Xylene (mixed isomers), Ethylene

View the full list of 40 chemicals below.

Chemicals Released (2014-2024, 10-Year Total) (40 chemicals)

#	Chemical	CAS#	Air (lbs, 10yr)	Water (lbs, 10yr)	Total (lbs, 10yr)
1	Methanol	67-56-1	270,817	0	270,817
2	Ammonia	7664-41-7	97,313	0	97,313
3	Vinyl acetate	108-05-4	70,754	0	70,754
4	Xylene (mixed isomers)	1330-20-7	45,323	33	45,365
5	Ethylene	74-85-1	40,183	0	40,183
6	1,2,4-Trimethylbenzene	95-63-6	36,587	105	36,695
7	Toluene	108-88-3	29,713	27	29,749
8	n-Hexane	110-54-3	20,905	170	21,076
9	Boron trifluoride	7637-07-2	14,388	0	14,388
10	Benzene	71-43-2	11,221	24	11,247
11	Dimethylamine	124-40-3	6,912	0	6,912
12	Chlorine	7782-50-5	6,383	0	6,383
13	Acetaldehyde	75-07-0	6,116	0	6,116
14	Ethylbenzene	100-41-4	5,951	22	5,975
15	Phenol	108-95-2	5,078	0	5,078
16	Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7647-01-0	5,066	0	5,066
17	Zinc compounds	N982	4,126	0	4,126
18	Formaldehyde	50-00-0	3,141	0	3,141
19	Ethylene glycol	107-21-1	2,254	0	2,254
20	Acrylonitrile	107-13-1	2,224	0	2,224
21	Propylene oxide	75-56-9	1,829	0	1,829
22	o-Cresol	95-48-7	1,585	0	1,585
23	Cumene	98-82-8	1,513	10	1,524
24	Formic acid	64-18-6	1,406	0	1,406
25	Maleic anhydride	108-31-6	1,009	0	1,009
26	Cyclohexane	110-82-7	995	0	995
27	Naphthalene	91-20-3	935	21	957
28	1,3-Butadiene	106-99-0	312	0	312
29	Diethanolamine	111-42-2	205	0	205
30	Diphenylamine	122-39-4	118	0	118
31	Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7664-93-9	96	0	96
32	Chromium	7440-47-3	0	33	33
33	Nickel	7440-02-0	0	31	31
34	Lead And Lead Compounds	N420	3	22	25
35	Lead compounds	N420	1	22	22
36	Certain glycol ethers	N230	12	0	12
37	Methyl tert-butyl ether	1634-04-4	2	5	10
38	Polycyclic aromatic compounds	N590	2	2	4
39	Piperonyl butoxide	51-03-6	4	0	4
40	Mercury And Mercury Compounds	N458	1	0	1

Top chemicals released near this property (2024 only):

Methanol, Ethylene, Ammonia, Vinyl acetate, 1,2,4-Trimethylbenzene

View the full list of 35 chemicals reported within 2 miles for 2024.

Chemicals Released (2024 Only) (35 chemicals)

#	Chemical	CAS#	Air (lbs/yr)	Water (lbs/yr)	Total (lbs/yr)
1	Methanol	67-56-1	15,808	0	42,599
2	Ethylene	74-85-1	30,650	0	30,650
3	Ammonia	7664-41-7	11,128	0	19,596
4	Vinyl acetate	108-05-4	5,850	0	5,852
5	1,2,4-Trimethylbenzene	95-63-6	4,000	0	4,520
6	n-Hexane	110-54-3	4,280	0	4,280
7	Xylene (mixed isomers)	1330-20-7	3,675	5	3,785
8	Phenol	108-95-2	2,206	0	3,579
9	Formaldehyde	50-00-0	354	0	3,326
10	Toluene	108-88-3	2,900	3	2,903
11	Formic acid	64-18-6	189	0	1,968
12	Boron trifluoride	7637-07-2	1,178	0	1,178
13	Benzene	71-43-2	1,130	2	1,132
14	o-Cresol	95-48-7	88	0	1,122
15	Dimethylamine	124-40-3	864	0	884
16	Chlorine	7782-50-5	487	0	487
17	Ethylbenzene	100-41-4	427	3	430
18	Zinc compounds	N982	323	0	323
19	1,3-Butadiene	106-99-0	295	0	295
20	Acrylonitrile	107-13-1	278	0	294
21	Cumene	98-82-8	183	0	287
22	Maleic anhydride	108-31-6	132	0	281
23	Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7647-01-0	265	0	265
24	Propylene oxide	75-56-9	255	0	255
25	Cyclohexane	110-82-7	232	0	232
26	Naphthalene	91-20-3	132	1	133
27	Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7664-93-9	96	0	96
28	Ethylene glycol	107-21-1	30	0	50
29	Acetaldehyde	75-07-0	45	0	45
30	Diphenylamine	122-39-4	23	0	23
31	Chromium	7440-47-3	0	2	8
32	Nickel	7440-02-0	0	2	6
33	Lead And Lead Compounds	N420	1	1	1
34	Certain glycol ethers	N230	1	0	1
35	Polycyclic aromatic compounds	N590	0	0	1