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Stormwater Ponds in Coastal South Carolina Appendix A6-1 – Economic Survey Methods

Methods

In order to better understand the accrued costs of stormwater pond management and maintenance, we implemented an anonymous online survey and conducted directed interviews for pond owners, managers, HOAs, real estate professionals, and other stakeholders. The objective of the survey was to engage members of the pond management community to acquire information and data on the lifecycle costs faced by the various stakeholders.

The survey and directed interviews asked the stakeholders about direct and indirect costs of stormwater pond construction, permitting, maintenance, and other environmental costs. The responding managers and maintenance personnel reported the direct or economic costs of construction, permitting, and maintenance. The responding members of HOAs, for example, reported environmental costs and costs associated with ongoing maintenance.

The survey contact list was based on two different sources: the South Carolina Association of Stormwater Managers (SCASM) listserv and the South Carolina Department of Health and Environmental Control (DHEC). DHEC is responsible for the management of stormwater control throughout the state of South Carolina, including its eight coast counties (Drescher, 2007). The research team was granted permission to distribute the survey invitation via SCASM’s listserv. Thus, the survey was mostly distributed to stormwater practitioners and developers in the state of South Carolina.

The survey was ultimately distributed to approximately 500 individuals between the two databases of contacts. An initial invitation to participate with the survey was distributed on May 15, 2015, and two reminders were distributed to the contact list in two-week intervals following the initial announcement. Of these 500 invitees, approximately 68 individuals responded to the survey, which represents a response rate of 13.6 percent. Unfortunately, some of the respondents did not complete the survey, so we ended up with 58 fully completed responses.

Questions

Q1 Do you operate in a public or private organization?

  • Public (1)
  • Private (2)
  • I do not know (3)
  • Other (4)

Q2 What is your organization’s inspection budget (that is, for inspecting stormwater ponds and related infrastructure) per year?

  • Less than or equal to $10,000 (1)
  • Greater than $10,000 but less than $15,000 (2)
  • Greater than $15,000 but less than $20,000 (3)
  • Greater than $20,000 but less than $25,000 (4)
  • Greater than $25,000 but less than $30,000 (5)
  • Greater than $30,000 but less than $40,000 (6)
  • Greater than $40,000 but less than $45,000 (7)
  • Greater than $45,000 but less than $50,000 (8)
  • Greater than $50,000 (9)
  • I do not know (10)
  • I prefer not to answer this question (11)
  • My organization does not perform inspections (12)

Q3 What percentage of private (or residential) storm water ponds does your organization inspect?

  • 0 to 25 percent (1)
  • 25 to 50 percent (2)
  • 50 to 75 percent (3)
  • 75 to 100 percent (4)
  • I do not know (5)
  • My organization does not perform inspections (6)

Q4 What percentage of public (or commercial) stormwater ponds does your organization inspect?

  • 0 to 25 percent (1)
  • 25 to 50 percent (2)
  • 50 to 75 percent (3)
  • 75 to 100 percent (4)
  • I do not know (5)
  • My organization does not perform inspections (6)

Q5 What is your organization’s annual budget for maintaining private stormwater ponds and related infrastructure?

  • Less than or equal to $10,000 (1)
  • Greater than $10,000 but less than $15,000 (2)
  • Greater than $15,000 but less than $20,000 (3)
  • Greater than $20,000 but less than $25,000 (4)
  • Greater than $25,000 but less than $30,000 (5)
  • Greater than $30,000 but less than $40,000 (6)
  • Greater than $40,000 but less than $45,000 (7)
  • Greater than $45,000 but less than $50,000 (8)
  • Greater than $50,000 (9)
  • I do not know (10)
  • I prefer not to answer this question (11)
  • My organization does not maintain private stormwater ponds and related infrastructure (12)

Q6 How many private stormwater ponds (and related infrastructure)  does your organization manage?

  • One to ten ponds (1)
  • Ten to twenty ponds (2)
  • Twenty to thirty ponds (3)
  • Thirty to forty ponds (4)
  • Forty to fifty ponds (5)
  • Fifty to sixty ponds (6)
  • Sixty to Seventy ponds (7)
  • Greater than seventy ponds (8)
  • I do not know (9)
  • I prefer not answer this question (10)
  • My organization does not manage private stormwater ponds and related infrastructure (11)

Q7 How many public stormwater ponds (and related infrastructure) does your organization manage?

  • One to ten ponds (1)
  • Ten to twenty ponds (2)
  • Twenty to thirty ponds (3)
  • Thirty to forty ponds (4)
  • Forty to fifty ponds (5)
  • Fifty to sixty ponds (6)
  • Sixty to Seventy ponds (7)
  • Greater than seventy ponds (8)
  • I do not know (9)
  • I prefer not answer this question (10)
  • My organization does not manage public stormwater ponds and related infrastructure (11)

Q8 What percentage of your organization’s stormwater pond (and related infrastructure) construction are retrofits?

  • 0 to 25 percent per year (1)
  • 25 to 50 percent per year (2)
  • 50 to 75 percent per year (3)
  • 75 to 100 percent per year (4)
  • My organization does not perform stormwater pond (and related infrastructure) construction retrofits (5)

Q9 What percentage of stormwater pond (and related infrastructure) construction is new construction for your organization?

  • 0 to 25 percent per year (1)
  • 25 to 50 percent per year (2)
  • 50 to 75 percent per year (3)
  • 50 to 75 percent per year (4)
  • My organization does not perform stormwater pond (and related infrastructure) new construction (5)

Q10 What is the average cost (excluding land costs) of a new construction, stormwater pond that your organization develops?

  • 0 to $10,000 per acre (1)
  • $10,000 to $20,000 per acre (2)
  • $20,000 to $30,000 per acre (3)
  • $30,000 to $40,000 per acre (4)
  • $40,000 to $50,000 per acre (5)
  • Greater than $50,000 per acre (6)
  • I do not know (7)
  • I prefer not to answer this question (8)
  • My organization does not perform stormwater pond (and related infrastructure) new construction (9)

Q11 What is the average volume of water in a new construction, stormwater pond that your organization develops?

  • 0 to 10,000 cubic feet (1)
  • 10,000 to 20,000 cubic feet (2)
  • 20,000 to 30,000 cubic feet (3)
  • 30,000 to 40,000 cubic feet (4)
  • 40,000 to 50,000 cubic feet (5)
  • 50,000 to 60,000 cubic feet (6)
  • Greater than 60,000 cubic feet (7)
  • I do not know (8)
  • I prefer not to answer this question (9)
  • My organization does not perform stormwater pond (and related infrastructure) new construction (10)

Q12 What is the average cost (excluding land costs) of a retrofitted stormwater pond?

  • 0 to $10,000 per acre (1)
  • $10,000 to $20,000 per acre (2)
  • $20,000 to $30,000 per acre (3)
  • $30,000 to $40,000 per acre (4)
  • $40,000 to $50,000 per acre (5)
  • Greater than $50,000 per acre (6)
  • I do not know (7)
  • I prefer not to answer this question (8)
  • My organization does not perform stormwater pond (and related infrastructure) construction retrofits (9)

Q13 What is the average number of acres of land used for a new construction, stormwater pond (and related infrastructure)?

  • 1 to 5 acres (1)
  • 5 to 10 acres (2)
  • 10 to 15 acres (3)
  • 15 to 20 acres (4)
  • 20 to 25 acres (5)
  • Greater than 25 acres (6)
  • I do not know (7)
  • I prefer not to answer this question (8)
  • My organization does not perform stormwater pond (and related infrastructure) construction retrofits (9)

Q14 What is the average cost (excluding land costs) of a Best Management Practice (BMP), new construction, stormwater pond? (Cost per development acre).

  • 0 to $10,000 per acre (1)
  • $10,000 to $20,000 per acre (2)
  • $20,000 to $30,000 per acre (3)
  • $30,000 to $40,000 per acre (4)
  • $40,000 to $50,000 per acre (5)
  • Greater than $50,000 per acre (6)
  • I do not know (7)
  • I prefer not to answer this question (8)
  • My organization does not perform stormwater pond (and related infrastructure) new construction (9)

Q15 How often does your company generally incur large maintenance costs?

  • Every year (1)
  • Every two years (2)
  • Every three years (3)
  • Every four years (4)
  • Every five years (5)
  • Every ten years or greater (6)
  • I do not know (7)
  • I do not prefer to answer this question (8)

Q16 What is generally included in your annual maintenance budget? (E.g., inspection costs, periodic dredging, etc.)

Q17 When your company incurs maintenance costs, what non-labor items are the funds generally spent on?

Q18 What is generally included in your annual maintenance budget? (e.g., inspection costs, periodic dredging, etc.)

Summary

As demonstrated below, approximately 68 percent of the respondents worked for the public sector and 18 percent worked for the private sector. The reader should bear in mind that unlike the literature review on stormwater maintenance costs, in which the researchers ascertained very specific information regarding costs, the purpose of the survey here was to gather initial information about maintenance activities and costs in state of South Carolina. (To the authors’ knowledge, this was the first survey of its kind in the state). In other words, the researchers’ objectives, within this study, were to gather information from the “30,000-foot” view of maintenance activities and costs in the state. (In the near future, the researchers plan to conduct a follow-up study and ask specific questions about maintenance and management costs regarding stormwater control). There is a large amount of data provided by the survey results, so for the sake of brevity we highlight some of the important findings here:

  • Annual inspection budgets yielded bi-modal distribution of responses.
    • The largest number of respondents had budgets that exceeded $50,000 per year, and the next largest number had budgets lesser than or equal to $10,000 per year.[1]
  • About one-in-four inspections are for private (or residential) ponds and about three-in-four inspections are for commercial (non-residential) ponds.
    • The largest number of respondents indicated that only one-in-four or less of their organization’s inspections include private stormwater ponds; however, most respondents indicated that three-in-four or more of their organization’s inspections were for commercial ponds.
  • A relatively small portion of annual budgets is dedicated toward maintenance.
    • The largest number of respondents indicated that less than $10,000 per year, of their organization’s annual budget, is dedicated toward stormwater maintenance and infrastructure development.[2]
  • The total number of ponds managed by respondents varied greatly
    • Six respondents identified fewer than 10 ponds and three respondents indicated greater than 70 ponds.
  • A relatively small portion of pond construction is dedicated to retrofits.[3]
    • The largest number of respondents indicated that only one-in-four or less of stormwater pond construction is dedicated to retrofits.
  • New stormwater pond construction costs vary greatly.
    • The largest number of respondents indicated that construction costs (excluding land costs) are less than $10,000 per acre.
  • The volumes of new constructed ponds vary greatly.
    • The largest number of respondents indicated greater than 60,000 cubic feet; however, the other respondents indicated all sorts of different volumes ranging from 10,000 to 60,000 cubic feet.
  • Percentage of newly constructed ponds is relatively small each year.
    • The largest number of respondents indicated that only about one-in-four ponds each year are dedicated to new construction; that is, of maintenance and construction activities, only 25 percent are dedicated toward new construction.
  • Average land area for new pond construction is relatively small.
    • A majority of respondents indicated that newly constructed ponds only require one to five acres of land.
  • The costs of construction for Best Management Practice ponds vary.[4]
    • A majority of respondents indicated that newly constructed BMP ponds cost up to $20,000 per acre.
  • A majority of management companies have large maintenance costs occurring at least once per year.

[1] A large percentage of persons who responded to this particular question indicated that they did conduct maintenance inspections.

[2] Given the anonymity of the respondents to the survey, the researchers do not know if elected HOA boards (managed by residents) or representatives from contracted management companies were the largest population to respond to this particular question.

[3] The researchers did not explicitly ask whether retrofits included “maintenance activities” as well. The specific definition of retrofits was not offered to the respondents, but the intent of retrofit was for major pond maintenance activities including dredging. Further, it is possible that retrofits can extend the initial lifecycle of the pond.

[4] A Best Management Pond is simply defined as the type of pond given the environmental needs of a particular project or area. For example, for residential neighborhoods with a large amount of impervious surface and little additional land for development, a stormwater pond (wet pond) is generally the best solution – hence, it is referred to as a Best Management Pond.

Full Survey Results

Q1 Do you operate in a public or private organization?

#AnswerResponse%
1Public4069%
2Private1628%
3I do not know12%
4Other12%

 

StatisticValue
Min Value1
Max Value4
Total Responses58

Q2 What is your organization’s inspection budget (that is, for inspecting stormwater ponds and related infrastructure) per year?

#AnswerResponse%
1Less than or equal to $10,0001018%
2Greater than $10,000 but less than $15,00059%
3Greater than $15,000 but less than $20,00035%
4Greater than $20,000 but less than $25,00012%
5Greater than $25,000 but less than $30,00012%
6Greater than $30,000 but less than $40,00000%
7Greater than $40,000 but less than $45,00000%
8Greater than $45,000 but less than $50,00000%
9Greater than $50,0001526%
10I do not know814%
11I prefer not to answer this question12%
12My organization does not perform inspections1323%
 Total57100%

 

StatisticValue
Min Value1
Max Value12
Mean7.37
Variance18.06
Standard Deviation4.25
Total Responses57

Q3 What percentage of private (or residential) storm water ponds does your organization inspect?

#AnswerResponse%
10 to 25 percent1425%
225 to 50 percent712%
350 to 75 percent47%
475 to 100 percent1323%
5I do not know47%
6My organization does not perform inspections1526%
 Total57100%

 

StatisticValue
Min Value1
Max Value6
Mean3.54
Variance3.75
Standard Deviation1.94
Total Responses57

Q4 What percentage of public (or commercial) stormwater ponds does your organization inspect?

#AnswerResponse%
10 to 25 percent916%
225 to 50 percent611%
350 to 75 percent35%
475 to 100 percent2137%
5I do not know47%
6My organization does not perform inspections1425%
 Total57100%

 

StatisticValue
Min Value1
Max Value6
Mean3.82
Variance2.97
Standard Deviation1.72
Total Responses57

Q5 What is your organization’s annual budget for maintaining private stormwater ponds and related infrastructure?

#AnswerResponse%
1Less than or equal to $10,0001221%
2Greater than $10,000 but less than $15,00012%
3Greater than $15,000 but less than $20,00012%
4Greater than $20,000 but less than $25,00000%
5Greater than $25,000 but less than $30,00024%
6Greater than $30,000 but less than $40,00000%
7Greater than $40,000 but less than $45,00000%
8Greater than $45,000 but less than $50,00000%
9Greater than $50,00035%
10I do not know24%
11I prefer not to answer this question24%
12My organization does not maintain private stormwater ponds and related infrastructure3460%
 Total57100%

 

StatisticValue
Min Value1
Max Value12
Mean8.84
Variance21.42
Standard Deviation4.63
Total Responses57

Q6 How many private stormwater ponds (and related infrastructure)  does your organization manage?

#AnswerResponse%
1One to ten ponds611%
2Ten to twenty ponds35%
3Twenty to thirty ponds12%
4Thirty to forty ponds24%
5Forty to fifty ponds00%
6Fifty to sixty ponds00%
7Sixty to Seventy ponds00%
8Greater than seventy ponds35%
9I do not know00%
10I prefer not answer this question00%
11My organization does not manage private stormwater ponds and related infrastructure4274%
 Total57100%

 

StatisticValue
Min Value1
Max Value11
Mean8.93
Variance14.07
Standard Deviation3.75
Total Responses57

Q7 How many public stormwater ponds (and related infrastructure) does your organization manage?

#

Answer

Response

%

1

One to ten ponds

17

30%

2

Ten to twenty ponds

5

9%

3

Twenty to thirty ponds

4

7%

4

Thirty to forty ponds

2

4%

5

Forty to fifty ponds

2

4%

6

Fifty to sixty ponds

1

2%

7

Sixty to Seventy ponds

2

4%

8

Greater than seventy ponds

3

5%

9

I do not know

1

2%

10

I prefer not answer this question

0

0%

11

My organization does not manage public stormwater ponds and related infrastructure

20

35%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

11

Mean

5.79

Variance

19.13

Standard Deviation

4.37

Total Responses

57

Q8 What percentage of your organization’s stormwater pond (and related infrastructure) construction are retrofits?

#

Answer

Response

%

1

0 to 25 percent per year

21

37%

2

25 to 50 percent per year

3

5%

3

50 to 75 percent per year

3

5%

4

75 to 100 percent per year

5

9%

5

My organization does not perform stormwater pond (and related infrastructure) construction retrofits

25

44%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

5

Mean

3.18

Variance

3.40

Standard Deviation

1.84

Total Responses

57

 

Q9 What percentage of stormwater pond (and related infrastructure) construction is new construction for your organization?

#

Answer

Response

%

1

0 to $10,000 per acre

7

13%

2

$10,000 to $20,000 per acre

3

5%

3

$20,000 to $30,000 per acre

2

4%

4

$30,000 to $40,000 per acre

4

7%

5

$40,000 to $50,000 per acre

0

0%

6

Greater than $50,000 per acre

3

5%

7

I do not know

12

21%

8

I prefer not to answer this question

1

2%

9

My organization does not perform stormwater pond (and related infrastructure) new construction

24

43%

 

Total

56

100%

 

Statistic

Value

Min Value

1

Max Value

9

Mean

6.45

Variance

8.69

Standard Deviation

2.95

Total Responses

56

 

Q10 What is the average cost (excluding land costs) of a new construction, stormwater pond that your organization develops?

#

Answer

Response

%

1

0 to 10,000 cubic feet

2

4%

2

10,000 to 20,000 cubic feet

3

5%

3

20,000 to 30,000 cubic feet

4

7%

4

30,000 to 40,000 cubic feet

5

9%

5

40,000 to 50,000 cubic feet

0

0%

6

50,000 to 60,000 cubic feet

0

0%

7

Greater than 60,000 cubic feet

6

11%

8

I do not know

14

25%

9

I prefer not to answer this question

0

0%

10

My organization does not perform stormwater pond (and related infrastructure) new construction

23

40%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

10

Mean

7.44

Variance

8.32

Standard Deviation

2.88

Total Responses

57

 

Q11 What is the average volume of water in a new construction, stormwater pond that your organization develops?

#

Answer

Response

%

1

0 to $10,000 per acre

6

11%

2

$10,000 to $20,000 per acre

4

7%

3

$20,000 to $30,000 per acre

3

5%

4

$30,000 to $40,000 per acre

2

4%

5

$40,000 to $50,000 per acre

1

2%

6

Greater than $50,000 per acre

2

4%

7

I do not know

18

32%

8

I prefer not to answer this question

1

2%

9

My organization does not perform stormwater pond (and related infrastructure) construction retrofits

20

35%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

9

Mean

6.35

Variance

7.95

Standard Deviation

2.82

Total Responses

57

 

Q12 What is the average cost (excluding land costs) of a retrofitted stormwater pond?

#

Answer

Response

%

1

0 to 25 percent per year

16

28%

2

25 to 50 percent per year

4

7%

3

50 to 75 percent per year

6

11%

4

50 to 75 percent per year

9

16%

5

My organization does not perform stormwater pond (and related infrastructure) new construction

22

39%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

5

Mean

3.30

Variance

2.86

Standard Deviation

1.69

Total Responses

57

 

Q13 What is the average number of acres of land used for a new construction, stormwater pond (and related infrastructure)?

#

Answer

Response

%

1

1 to 5 acres

27

47%

2

5 to 10 acres

4

7%

3

10 to 15 acres

2

4%

4

15 to 20 acres

0

0%

5

20 to 25 acres

0

0%

6

Greater than 25 acres

0

0%

7

I do not know

4

7%

8

I prefer not to answer this question

1

2%

9

My organization does not perform stormwater pond (and related infrastructure) construction retrofits

19

33%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

9

Mean

4.35

Variance

13.95

Standard Deviation

3.73

Total Responses

57

 

Q14 What is the average cost (excluding land costs) of a Best Management Practice (BMP), new construction, stormwater pond? (Cost per development acre).

#

Answer

Response

%

1

0 to $10,000 per acre

8

14%

2

$10,000 to $20,000 per acre

9

16%

3

$20,000 to $30,000 per acre

2

4%

4

$30,000 to $40,000 per acre

0

0%

5

$40,000 to $50,000 per acre

1

2%

6

Greater than $50,000 per acre

5

9%

7

I do not know

14

25%

8

I prefer not to answer this question

0

0%

9

My organization does not perform stormwater pond (and related infrastructure) new construction

18

32%

 

Total

57

100%

 

Statistic

Value

Min Value

1

Max Value

9

Mean

5.74

Variance

9.55

Standard Deviation

3.09

Total Responses

57

 

Q15 How often does your company generally incur large maintenance costs?

#

Answer

Response

%

1

Federal Government

0

0%

2

State Government

3

6%

3

Local Government

12

24%

4

Shared Responsibility

29

57%

5

I do not know

2

4%

6

I prefer not to answer this question

5

10%

 

Total

51

100%

 

Statistic

Value

Min Value

2

Max Value

6

Mean

3.88

Variance

0.91

Standard Deviation

0.95

Total Responses

51

 

Q16 How often does your company generally incur large maintenance costs?

#

Answer

Response

%

1

Every year

15

37%

2

Every two years

0

0%

3

Every three years

3

7%

4

Every four years

1

2%

5

Every five years

3

7%

6

Every ten years or greater

3

7%

7

I do not know

12

29%

8

I do not prefer to answer this question

4

10%

 

Total

41

100%

 

Statistic

Value

Min Value

1

Max Value

8

Mean

4.32

Variance

8.02

Standard Deviation

2.83

Total Responses

41

Q17 When your company incurs maintenance costs, what non-labor items are the funds generally spent on?

Text Response
labor by half or more, then equipment, then material
Mowing; Debris Cleaning/Removal; Clearing/Grubbing Vegetative Growth; Dredging
Materials
materials
fencing, grassing
chemicals, masonry, pipe
N/A
chemicals, equipment
BMPs
hydroseeding and disposing of waste/dredged materials
NA
fence materials, fuel, riprap
Pipe materails, restoration
Materials, debrie disposal
N/A
Trash removal, reseeding bare areas, cutting grass, etc.
replace structures
Dont know. My primary responsibility is permitting.
n/a
n/a
pipe, concrete, equipment
maaterials for maintaning wells natural and made made berms outfalls etc.
equipment maintenance
Equipment and herbicides.
n/a

 

StatisticValue
Total Responses25

Q18 What is generally included in your annual maintenance budget? (e.g., inspection costs, periodic dredging, etc.)

Text Response

Maintenance of 910 miles of stormwater conveyance

Inspection; Routine Maintenance; Scheduled Rehab

Cleaning of the piped systems.  We have maybe 5 ponds that we are responsible for and the maintenance is typically keeping the outfall cleaned and the banks cleared.  Inspections are done on a case by case basis.  There isnt a specific amount allocated for inspections but it is included in overall maintenance.

All

4 million

Grassing, miscellaneous & minor repairs, fencing

chemicals, masonry, pipe

N/A

inspections, vegetation control, algea control, dredging

stormwater inspections during construction

700,000

NA We are a design firm we do not maintain ponds

inspection, mowing, fence repaire mucking

160,000

8000

N/A

inspections, mowing, repair of side slopes, replacement of trees,etc.

Inspection and maintenance

Dont know. My primary responsibility is permitting.

n/a

annual maintenance

inspection, maintenance, upgrading

as atated above plus maintaing and replacing well pumps and sometime man mode and natural berms, dykes, and gates.

ditch cleaning

Inspection Costs with periodic herbicide treatment

inspection costs

 

Statistic

Value

Total Responses

26