Looking for a SWPPP consultant in Johnston, IA? Describe your project once and up to three stormwater consultants who work in Johnston and Polk County get back to you with a quote. It's free and there is no obligation.
Johnston is home to about 25,022 people (2024 Census Bureau estimate), a growing community (+4.5% since 2020). With 1,284 people per sq mi, it is a suburban area. Subdivisions and commercial sites here need stormwater permit coverage before grading.
Johnston at a glance
- Population (Census Bureau estimate, 2024)
- 25,022 (+4.5% since 2020)
- Rank in Iowa
- 20th of 940 cities and towns
- Land area
- 19 sq mi
- Population density
- 1,284 people per sq mi (suburban)
- Type
- City (Johnston city)
- Main county
- Polk County
What to check before hiring in Johnston
- Permit: in Iowa, check the state construction general permit.
- Local rules: Johnston may add its own erosion control permit.
- Records: keep inspection reports on site.
- Price drivers: site size, phases, inspection frequency and duration.
Useful official resources
-
EPA: construction stormwater
Official information and guidance.
-
EnviroCert: CPESC
Official information and guidance.
Services available in Johnston
-
SWPPP and permit coverage
Preparation of the SWPPP and notice of intent under the construction general permit.
-
Stormwater inspections
Routine and post-storm inspections with reports for the permit.
Frequently asked questions in Johnston
How much does a SWPPP cost in Johnston, IA?
It depends on site size, phases and inspections. Describe your project: consultants who serve Johnston reply with a quote.
How long does it take?
Plans often take days to a couple of weeks, plus the permit review.
What happens at the end?
A notice of termination is filed once the site is stabilized.
Which stormwater consultants will contact me?
Up to three independent stormwater consultants who serve Johnston and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.