A Report to the Iowa Department of Natural Resources I. Overview of the Iowa Lakes Valuation Project

Transcription

1 A Report to the Iowa Department of Natural Resources The Iowa Lakes Valuation Project 2009 Summary and Findings Keith S. Evans, Joseph A. Herriges, and Catherine L. Kling January 2011

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3 A Report to the Iowa Department of Natural Resources The Iowa Lakes Valuation Project 2009 Summary and Findings Keith S. Evans, Joseph A. Herriges, and Catherine L. Kling January 2011 The Iowa Lakes Valuation Project is an ongoing economic study of the use and value Iowans place on water quality in Iowa lakes. In this report, we summarize and interpret the main findings of the 2009 data collection component of the overall study. We begin with a brief introduction to the overall project, and then turn to a description of the survey design and implementation for the 2009 data collection effort. Finally, we present a summary of results from the survey. I. Overview of the Iowa Lakes Valuation Project The Iowa Lakes Valuation Project is a large, ongoing project to advance understanding about the lake visitation patterns and preferences of Iowans at a number of important lakes in the state. The project was designed to complement the research being done by Dr. John Downing and other members of the ISU Limnology Laboratory. This research has provided the Iowa Department of Natural Resources with a lake database that includes water chemistry, biological analysis, and watershed geographic information systems (GIS) data for 129 of Iowa s principal recreational lakes. Thus, the combined effort has resulted in detailed information on both the biological condition of Iowa lakes and the value and use of water quality improvements at those lakes. The study has been jointly funded by the Iowa Department of Natural Resources and the U.S. Environmental Protection Agency. The first year of data collection for the study in 2002 focused on providing a baseline of information on use and attitudes toward water quality measures and economic development. The second through fourth years of data collection also included collecting information on use but additionally provided scenarios to survey respondents to elicit their

4 willingness to pay for quality improvements. A website ( created with funding from the Iowa Department of Natural Resources has been developed that allows potential recreationists and policymakers to access the summary information on lake usage and water quality in an easily accessible manner. To gather the four years of data for the Iowa Lakes Survey Project, we administered surveys in 2002, 2003, 2004, and 2005 to a large sample of about 8,000 Iowans. This report provides information on the fifth year of data collection, which occurred in II. Design and Implementation of the Iowa Lakes Survey 2009 Structure of the Survey The Iowa Lakes Survey 2009 was divided into two main sections. In the first section, respondents were asked about their household lake visitation patterns during the 2009 calendar year. Respondents were asked to report the number of trips (including multi day trips) to the 132 lakes listed in Table 1, identified by the Iowa Department of Natural Resources, and they were provided with a map (Figure 1) showing the names and locations of the lakes. (All tables and figures are located at the end of the report.) Respondents were also asked about visitation patterns to lakes in bordering states and whether trips were taken to river or stream segments in Iowa. Additionally, respondents were asked to indicate which activities their household participated in during lake visits. The actual survey questions can be found in a copy of the final survey instrument included in the appendix. Additionally, respondents were presented with a pair of choice experiments. In each experiment, respondents were asked to consider two hypothetical lakes with the same shape but which differed in terms of water quality, distance from home, and entrance fee. 1 1 Data summaries and analysis of the choice experiment data will be available in separate research articles when completed. 2

5 In the final section, sociodemographic information was gathered from respondents. Information collected in this section included age, gender, education, household size, employment status, income, and whether the individual owned a boat in Design of the Survey Instrument An initial survey design with each of these components was completed in early summer of Two focus group sessions were then conducted in late July and early August to fine tune the wording of the survey and to ensure that the questions and instructions were clear to potential survey respondents. Finally, a pre test of the survey instrument was mailed to a random sample of 200 residents in September, as a further check on both the survey instrument and the implementation procedures. Administration of the Survey After revising the survey instrument in response to the focus groups and the pretest sample, the final survey was mailed to 10,000 Iowa households: 4,600 Iowa residents that responded to the 2005 Iowa Lakes Survey and 5,400 randomly selected Iowa residents. Sample households were sent a packet that contained the survey, a map of Iowa lakes, a cover letter explaining the purpose and timeframe of the study, a self addressed and stamped return envelope for the completed survey, and a payment slip. When respondents returned their survey with a copy of the payment slip completed, they were sent a check for $12 as a partial compensation for their time. Respondents who did not return the survey within three weeks were sent a postcard reminder. If they still did not respond after another three to four weeks, they were sent a replacement packet containing the complete set of materials that were sent initially. Versions 1 through 3 of the survey were sent to 2,500 households, randomly assigned between previous participants and the random sample. Version 4 of the survey was sent to a random sample of 2,500 Iowa households. Of the 10,000 surveys sent out, 144 were returned by the postal service as undeliverable because 3

6 the addressee was deceased or had moved, and 138 households refused the mailing. There were 6,043 respondents who chose to return the survey by mail, generating a 61.3% response rate among deliverable surveys. III. Survey Results Lake Usage of Respondents On average, a large proportion of respondents reported taking at least one singleday trip during the 2009 calendar year. Approximately 59% of respondents reported at least one single day trip, while about 2% reported taking at least one overnight trip. The average number of single day trips by respondents was 8.6; the average number of single day trips by households that reported taking at least one trip was The average number of overnight trips by respondents was significantly lower, with 1.4 over the complete sample of respondents and 6.3 among trip takers. Tables 2 and 3 list some basic summary statistics on the visitation patterns of respondents categorized by lake. The average number of single day trips to a particular lake among all respondents varied between 0.01 and 0.75 (Mean 1). When conditioned on households that answered affirmatively to taking trips to the specific lake, the average number of trips varied between 1.48 and 7.44 (Mean 3). The column labeled Mean 2 contains the average number of single day trips to a particular lake by trip takers. The top five most visited lakes by respondents were Saylorville Lake, Clear Lake, West Okoboji Lake, Coralville Lake, and Big Creek Lake, respectively. The five least visited lakes by respondents were Slip Bluff Lake, Pierce Creek Lake, Windmill Lake, Fogle Lake, and Bob White Lake. Respondents also took trips to lakes in the states bordering Iowa, as well as to the Mississippi and Missouri Rivers. Tables 4 and 5 list some basic statistics on the respondents visitation patterns to these lakes and rivers. In contrast with the previously reported statistics, only 19.1% of respondents reported at least one single day trip to a lake in a bordering state; 20.1% reported taking at least one 4

7 overnight trip. When asked about trips to the bordering rivers, approximately 26.5% of respondents reported at least one single day trip while only 7.8% reported taking at least one overnight trip. Sixty one percent of respondents reported visiting a river or stream segment in Iowa, including the Mississippi and Missouri Rivers, in the 2009 calendar year. The majority of single day trips to lakes in states bordering Iowa were in Minnesota, averaging 0.21 trips in the 2009 calendar year. In contrast, the fewest number of single day trips took place to lakes in Nebraska, averaging 0.04 trips. Respondents took a sizable number of single day trips to the Mississippi River, averaging 1.25 trips, whereas respondents participated in an average of only 0.29 trips to the Missouri River. The same visitation pattern is observed with overnight trips to lakes in bordering states and the river segments bordering Iowa. Respondents reported an average of 0.25 overnight trips to lakes in Minnesota in the 2009 calendar year but only 0.02 on average to lakes in Nebraska. The Mississippi River received an average of 0.24 overnight trips whereas respondents participated in an average of only 0.05 overnight trips to the Missouri River. Lake Activities of Respondents Respondents were asked to select the activities that they commonly participate in during a visit to an Iowa lake. Figure 2 depicts the frequency with which respondents selected these activities. The top four activities selected by respondents were fishing, picnicking, nature/wildlife watching, and boating, respectively. The bottom four activities were sailing, snowmobiling, jet skiing, and hunting, respectively. These results are consistent with 25% of respondents reporting boat ownership. 5

8 Respondent Demographics Respondents varied in age, employment status, size of their household, income, and education. In this section, we provide some basic summary statistics regarding the demographic characteristics of respondents. Figure 3 illustrates the age distribution among respondents. The majority of respondents were between the ages of 35 and 75, with 61% being male. The largest group of respondents contained individuals between the ages of 60 and 75. This is consistent with Figure 4, which displays the employment status of respondents: 36% were retired, while 52% were employed full time. Table 6 contains information on the households of respondents. The average number of adults within households was On average, these households contained 0.53 children. This created an average household (family) size of about 2.33, which is in line with the 2008 average Iowa family size of Figure 5 depicts the distribution of income among respondents. Forty eight percent reported an annual income between $40,000 and $99,999, with the largest portion of those falling between $75,000 and $99,999. This is consistent with reported education levels among respondents, illustrated in Figure 6. A majority of respondents, 69%, have received at least some college education. Approximately 37% of respondents reported obtaining at least a college degree, and 12% reported having an advanced degree. Total Usage of Iowa Lakes by Iowa Households Using information collected from the Iowa Lakes surveys 2002 through 2005 and 2009 and a follow up survey of non respondents in 2002, we estimated the total 2 For more information about Iowa demographics, refer to the State Data Center at the State Library of Iowa ( 6

9 number of single day household trips to 132 Iowa lakes by all Iowans. 3 Table 7 contains estimated household trips categorized by lake. The four year average between 2002 and 2005 and the percentage change between this four year average and 2009 are also included. Overall, Iowa lakes experienced an increase in the intensity of visitation. Specifically, the average lake in Iowa experienced a 32.7% increase in visitation. Part of this increase is explained simply by an increase in the number of households in Iowa. The overall predicted increase is not uniformly enjoyed at all lakes. There exists a considerable amount of variation at the individual lake level, ranging from over a 150% increase in household visitation to a 22% decrease. The top five most heavily visited lakes in 2009 were Saylorville Lake, Coralville Lake, Clear Lake, West Okoboji Lake, and Big Creek Lake, respectively. The five least visited lakes were Slip Bluff Lake, Manteno Lake, Pierce Creek Lake, Meadow Lake, and Oldham Lake. Table 8 contains the ranking of Iowa lakes according to the intensity of household visitation under the four year average and in 2009, as described in Table 7. Also included is the change in overall ranking between the four year average and This column captures substitution between lakes. The five lakes with the largest change in rankings between the four year average and 2009 are Silver Lake (Dickinson County), Lake Minnewashta, Viking Lake, Roberts Creek Lake, and Silver Lake (Delaware County), respectively. In contrast, the five lakes that experienced the largest drop in rankings are Hawthorn lake (aka Barnes City Lake), Badger Lake, Beeds Lake, Lower Pine Lake, and Upper Pine Lake. 3 A complete description of the calculation is available from the authors upon request. 7

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11 TABLES AND FIGURES Table 1. Iowa Lakes Included in Survey DNR # Lake Name DNR # Lake Name 1 Arbor Lake 38 George Wyth Lake 2 Arrowhead Lake (Pottawattamie County) 39 Green Belt Lake 3 Arrowhead Lake (Sac County) 40 Green Castle Lake 4 Avenue of the Saints Lake 41 Green Valley Lake 5 Badger Creek Lake 42 Greenfield Lake 6 Badger Lake 43 Hannen Lake 7 Beaver Lake 44 Hawthorn Lake (aka Barnes City Lake) 8 Beeds Lake 45 Hickory Grove Lake 9 Big Creek Lake 46 Hooper Area Pond 10 Big Spirit Lake 47 Indian Lake 11 Black Hawk Lake 48 Ingham Lake 12 Blue Lake 49 Kent Park Lake 13 Bob White Lake 50 Lacey Keosauqua Park Lake 14 Briggs Woods Lake 51 Lake Ahquabi 15 Browns Lake 52 Lake Anita 16 Brushy Creek Lake 53 Lake Cornelia 17 Carter Lake 54 Lake Darling 18 Casey Lake (aka Hickory Hills Lake) 55 Lake Geode 19 Center Lake 56 Lake Hendricks 20 Central Park Lake 57 Lake Icaria 21 Clear Lake 58 Lake Iowa 22 Cold Springs Lake 59 Lake Keomah 23 Coralville Lake 60 Lake Manawa 24 Crawford Creek Impoundment 61 Lake MacBride 25 Crystal Lake 62 Lake Meyer 26 Dale Maffitt Lake 63 Lake Miami 28 DeSoto Bend Lake 64 Lake Minnewashta 29 Diamond Lake 65 Lake of the Hills 30 Dog Creek Lake 66 Lake of Three Fires 31 Don Williams Lake 67 Lake Orient 32 East Lake (Osceola) 68 Lake Pahoja 33 East Okoboji Lake 69 Lake Smith 34 Easter Lake 70 Lake Sugema 35 Eldred Sherwood Lake 71 Lake Wapello 36 Five Island Lake 72 Little River 37 Fogle Lake 73 Little Sioux Park Lake 9

12 Table 1. Continued DNR # Lake Name DNR # Lake Name 74 Little Spirit Lake 104 Saylorville Lake 75 Little Wall Lake 105 Silver Lake (Dickinson County) 76 Littlefield Lake 106 Silver Lake (Worth County) 77 Lost Island Lake 107 Silver Lake (Delaware County) 78 Lower Gar Lake 108 Silver Lake (Palo Alto County) 79 Lower Pine Lake 109 Slip Bluff Lake 80 Manteno Lake 110 South Prairie Lake 81 Mariposa Lake 111 Spring Lake 82 Meadow Lake 112 Springbrook Lake 83 Meyers Lake 113 Storm Lake (incl Little Storm Lake) 84 Mill Creek (Lake) 114 Swan Lake 85 Mitchell Lake 115 Thayer Lake 86 Moorehead Lake 116 Three Mile Lake 87 Mormon Trail Lake 117 Trumbull Lake 88 Nelson Park Lake 118 Tuttle Lake 89 Nine Eagles Lake 119 Twelve Mile Creek Lake 90 North Twin Lake 120 Union Grove Lake 91 Oldham Lake 121 Upper Gar Lake 92 Otter Creek Lake 122 Upper Pine Lake 93 Ottumwa Lagoon 123 Viking Lake 94 Pierce Creek Lake 124 Volga Lake 95 Pleasant Creek Lake 125 West Okoboji Lake 96 Pollmiller Park Lake 126 West Osceola 97 Prairie Rose Lake 127 White Oak Lake 98 Rathbun Lake 128 Williamson Pond 99 Red Haw Lake 129 Willow Lake 100 Red Rock Lake 130 Wilson Park Lake 101 Roberts Creek Lake 131 Windmill Lake 102 Rock Creek Lake 132 Yellow Smoke Park Lake 103 Rodgers Park Lake 133 Other lakes in Iowa 10

13 11 Table 2. Single Day Trips to Iowa Lakes DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 1 Arbor Lake % 2 Arrowhead Lake (Pottawattamie County) % 3 Arrowhead Lake (Sac County) % 4 Avenue of the Saints Lake % 5 Badger Creek Lake % 6 Badger Lake % 7 Beaver Lake % 8 Beeds Lake % 9 Big Creek Lake % 10 Big Spirit Lake % 11 Black Hawk Lake % 12 Blue Lake % 13 Bob White Lake % 14 Briggs Woods Lake % 15 Browns Lake % 16 Brushy Creek Lake % 17 Carter Lake % 18 Casey Lake (aka Hickory Hills Lake) % 19 Center Lake % 20 Central Park Lake % 21 Clear Lake % 22 Cold Springs Lake % 23 Coralville Lake % 24 Crawford Creek Impoundment % 25 Crystal Lake % 26 Dale Maffitt Lake %

14 12 Table 2. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 28 DeSoto Bend Lake % 29 Diamond Lake % 30 Dog Creek Lake % 31 Don Williams Lake % 32 East Lake (Osceola) % 33 East Okoboji Lake % 34 Easter Lake % 35 Eldred Sherwood Lake % 36 Five Island Lake % 37 Fogle Lake % 38 George Wyth Lake % 39 Green Belt Lake % 40 Green Castle Lake % 41 Green Valley Lake % 42 Greenfield Lake % 43 Hannen Lake % 44 Hawthorn Lake (aka Barnes City Lake) % 45 Hickory Grove Lake % 46 Hooper Area Pond % 47 Indian Lake % 48 Ingham Lake % 49 Kent Park Lake % 50 Lacey Keosauqua Park Lake % 51 Lake Ahquabi % 52 Lake Anita % 53 Lake Cornelia %

15 13 Table 2. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 54 Lake Darling % 55 Lake Geode % 56 Lake Hendricks % 57 Lake Icaria % 58 Lake Iowa % 59 Lake Keomah % 60 Lake Manawa % 61 Lake MacBride % 62 Lake Meyer % 63 Lake Miami % 64 Lake Minnewashta % 65 Lake of the Hills % 66 Lake of Three Fires % 67 Lake Orient % 68 Lake Pahoja % 69 Lake Smith % 70 Lake Sugema % 71 Lake Wapello % 72 Little River % 73 Little Sioux Park Lake % 74 Little Spirit Lake % 75 Little Wall Lake % 76 Littlefield Lake % 77 Lost Island Lake % 78 Lower Gar Lake % 79 Lower Pine Lake %

16 14 Table 2. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 80 Manteno Lake % 81 Mariposa Lake % 82 Meadow Lake % 83 Meyers Lake % 84 Mill Creek (Lake) % 85 Mitchell Lake % 86 Moorehead Lake % 87 Mormon Trail Lake % 88 Nelson Park Lake % 89 Nine Eagles Lake % 90 North Twin Lake % 91 Oldham Lake % 92 Otter Creek Lake % 93 Ottumwa Lagoon % 94 Pierce Creek Lake % 95 Pleasant Creek Lake % 96 Pollmiller Park Lake % 97 Prairie Rose Lake % 98 Rathbun Lake % 99 Red Haw Lake % 100 Red Rock Lake % 101 Roberts Creek Lake % 102 Rock Creek Lake % 103 Rodgers Park Lake % 104 Saylorville Lake % 105 Silver Lake (Dickinson County) %

17 15 Table 2. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 106 Silver Lake (Worth County) % 107 Silver Lake (Delaware County) % 108 Silver Lake (Palo Alto County) % 109 Slip Bluff Lake % 110 South Prairie Lake % 111 Spring Lake % 112 Springbrook Lake % 113 Storm Lake (incl Little Storm Lake) % 114 Swan Lake % 115 Thayer Lake % 116 Three Mile Lake % 117 Trumbull Lake % 118 Tuttle Lake % 119 Twelve Mile Creek Lake % 120 Union Grove Lake % 121 Upper Gar Lake % 122 Upper Pine Lake % 123 Viking Lake % 124 Volga Lake % 125 West Okoboji Lake % 126 West Osceola % 127 White Oak Lake % 128 Williamson Pond % 129 Willow Lake % 130 Wilson Park Lake % 131 Windmill Lake %

18 Table 2. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 132 Yellow Smoke Park Lake % 133 Other lakes in Iowa Total 51, a Mean 1 = average sample trips to lake b Mean 2 = average trips to lake by all trip takers c Mean 3 = average trips to trip takers at that lake 16

19 17 Table 3. Overnight Trips to Iowa Lakes DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 1 Arbor Lake % 2 Arrowhead Lake (Pottawattamie County) % 3 Arrowhead Lake (Sac County) % 4 Avenue of the Saints Lake % 5 Badger Creek Lake % 6 Badger Lake % 7 Beaver Lake % 8 Beeds Lake % 9 Big Creek Lake % 10 Big Spirit Lake % 11 Black Hawk Lake % 12 Blue Lake % 13 Bob White Lake % 14 Briggs Woods Lake % 15 Browns Lake % 16 Brushy Creek Lake % 17 Carter Lake % 18 Casey Lake (aka Hickory Hills Lake) % 19 Center Lake % 20 Central Park Lake % 21 Clear Lake % 22 Cold Springs Lake % 23 Coralville Lake % 24 Crawford Creek Impoundment % 25 Crystal Lake % 26 Dale Maffitt Lake %

20 18 Table 3. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 28 DeSoto Bend Lake % 29 Diamond Lake % 30 Dog Creek Lake % 31 Don Williams Lake % 32 East Lake (Osceola) % 33 East Okoboji Lake % 34 Easter Lake % 35 Eldred Sherwood Lake % 36 Five Island Lake % 37 Fogle Lake % 38 George Wyth Lake % 39 Green Belt Lake % 40 Green Castle Lake % 41 Green Valley Lake % 42 Greenfield Lake % 43 Hannen Lake % 44 Hawthorn Lake (aka Barnes City Lake) % 45 Hickory Grove Lake % 46 Hooper Area Pond % 47 Indian Lake % 48 Ingham Lake % 49 Kent Park Lake % 50 Lacey Keosauqua Park Lake % 51 Lake Ahquabi % 52 Lake Anita % 53 Lake Cornelia %

21 19 Table 3. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 54 Lake Darling % 55 Lake Geode % 56 Lake Hendricks % 57 Lake Icaria % 58 Lake Iowa % 59 Lake Keomah % 60 Lake Manawa % 61 Lake MacBride % 62 Lake Meyer % 63 Lake Miami % 64 Lake Minnewashta % 65 Lake of the Hills % 66 Lake of Three Fires % 67 Lake Orient % 68 Lake Pahoja % 69 Lake Smith % 70 Lake Sugema % 71 Lake Wapello % 72 Little River % 73 Little Sioux Park Lake % 74 Little Spirit Lake % 75 Little Wall Lake % 76 Littlefield Lake % 77 Lost Island Lake % 78 Lower Gar Lake % 79 Lower Pine Lake %

22 20 Table 3. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 80 Manteno Lake % 81 Mariposa Lake % 82 Meadow Lake % 83 Meyers Lake % 84 Mill Creek (Lake) % 85 Mitchell Lake % 86 Moorehead Lake % 87 Mormon Trail Lake % 88 Nelson Park Lake % 89 Nine Eagles Lake % 90 North Twin Lake % 91 Oldham Lake % 92 Otter Creek Lake % 93 Ottumwa Lagoon % 94 Pierce Creek Lake % 95 Pleasant Creek Lake % 96 Pollmiller Park Lake % 97 Prairie Rose Lake % 98 Rathbun Lake % 99 Red Haw Lake % 100 Red Rock Lake % 101 Roberts Creek Lake % 102 Rock Creek Lake % 103 Rodgers Park Lake % 104 Saylorville Lake % 105 Silver Lake (Dickinson County) %

23 21 Table 3. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 106 Silver Lake (Worth County) % 107 Silver Lake (Delaware County) % 108 Silver Lake (Palo Alto County) % 109 Slip Bluff Lake % 110 South Prairie Lake % 111 Spring Lake % 112 Springbrook Lake % 113 Storm Lake (incl Little Storm Lake) % 114 Swan Lake % 115 Thayer Lake % 116 Three Mile Lake % 117 Trumbull Lake % 118 Tuttle Lake % 119 Twelve Mile Creek Lake % 120 Union Grove Lake % 121 Upper Gar Lake % 122 Upper Pine Lake % 123 Viking Lake % 124 Volga Lake % 125 West Okoboji Lake % 126 West Osceola % 127 White Oak Lake % 128 Williamson Pond % 129 Willow Lake % 130 Wilson Park Lake % 131 Windmill Lake %

24 Table 3. Continued DNR # Lake Total Min Max Mean 1 a Mean 2 b Mean 3 c Share 132 Yellow Smoke Park Lake % 133 Other lakes in Iowa % Total 8, a Mean 1 = average sample trips to lake b Mean 2 = average trips to lake by all trip takers c Mean 3 = average trips to trip takers at that lake 22

25 Table 4. Single Day Trips to Bordering State Lakes and Rivers Lake Total Min Max Mean Lakes in Illinois Lakes in Minnesota Lakes in Missouri Lakes in Nebraska Lakes in South Dakota Lakes in Wisconsin Missouri River Mississippi River Table 5. Overnight Trips to Bordering State Lakes and Rivers Lake Total Min Max Mean Lakes in Illinois Lakes in Minnesota Lakes in Missouri Lakes in Nebraska Lakes in South Dakota Lakes in Wisconsin Missouri River Mississippi River Table 6. Household Size Number Adults Children Family > Mean

26 24 Table 7. Estimated Household Trips DNR # Lake Year Average 2009 % Change 4 Year to Arbor Lake % 2 Arrowhead Lake (Pottawattamie County) % 3 Arrowhead Lake (Sac County) % 4 Avenue of the Saints Lake % 5 Badger Creek Lake % 6 Badger Lake % 7 Beaver Lake % 8 Beeds Lake % 9 Big Creek Lake % 10 Big Spirit Lake % 11 Black Hawk Lake % 12 Blue Lake % 13 Bob White Lake % 14 Briggs Woods Lake % 15 Browns Lake % 16 Brushy Creek Lake % 17 Carter Lake % 18 Casey Lake (aka Hickory Hills Lake) % 19 Center Lake % 20 Central Park Lake % 21 Clear Lake % 22 Cold Springs Lake % 23 Coralville Lake % 24 Crawford Creek Impoundment %

27 25 Table 7. Continued DNR # Lake Year Average 2009 % Change 4 Year to Crystal Lake % 26 Dale Maffitt Lake % 28 DeSoto Bend Lake % 29 Diamond Lake % 30 Dog Creek Lake % 31 Don Williams Lake % 32 East Lake (Osceola) % 33 East Okoboji Lake % 34 Easter Lake % 35 Eldred Sherwood Lake % 36 Five Island Lake % 37 Fogle Lake % 38 George Wyth Lake % 39 Green Belt Lake % 40 Green Castle Lake % 41 Green Valley Lake % 42 Greenfield Lake % 43 Hannen Lake % 44 Hawthorn Lake (aka Barnes City Lake) % 45 Hickory Grove Lake % 46 Hooper Area Pond % 47 Indian Lake % 48 Ingham Lake % 49 Kent Park Lake % 50 Lacey Keosauqua Park Lake %

28 26 Table 7. Continued DNR # Lake Year Average 2009 % Change 4 Year to Lake Ahquabi % 52 Lake Anita % 53 Lake Cornelia % 54 Lake Darling % 55 Lake Geode % 56 Lake Hendricks % 57 Lake Icaria % 58 Lake Iowa % 59 Lake Keomah % 60 Lake Manawa % 61 Lake MacBride % 63 Lake Miami % 64 Lake Minnewashta % 65 Lake of the Hills % 66 Lake of Three Fires % 67 Lake Orient % 68 Lake Pahoja % 69 Lake Smith % 70 Lake Sugema % 71 Lake Wapello % 72 Little River % 73 Little Sioux Park Lake % 74 Little Spirit Lake % 75 Little Wall Lake % 76 Littlefield Lake %

29 27 Table 7. Continued DNR # Lake Year Average 2009 % Change 4 Year to Lost Island Lake % 78 Lower Gar Lake % 79 Lower Pine Lake % 80 Manteno Lake % 81 Mariposa Lake % 82 Meadow Lake % 83 Meyers Lake % 84 Mill Creek (Lake) % 85 Mitchell Lake % 86 Moorehead Lake % 87 Mormon Trail Lake % 88 Nelson Park Lake % 89 Nine Eagles Lake % 90 North Twin Lake % 91 Oldham Lake % 92 Otter Creek Lake % 93 Ottumwa Lagoon % 94 Pierce Creek Lake % 95 Pleasant Creek Lake % 96 Pollmiller Park Lake % 97 Prairie Rose Lake % 98 Rathbun Lake % 99 Red Haw Lake % 100 Red Rock Lake % 101 Roberts Creek Lake %

30 28 Table 7. Continued DNR # Lake Year Average 2009 % Change 4 Year to Rock Creek Lake % 103 Rodgers Park Lake % 104 Saylorville Lake % 105 Silver Lake (Dickinson County) % 106 Silver Lake (Worth County) % 107 Silver Lake (Delaware County) % 108 Silver Lake (Palo Alto County) % 109 Slip Bluff Lake % 110 South Prairie Lake % 111 Spring Lake % 112 Springbrook Lake % 113 Storm Lake (incl Little Storm Lake) % 114 Swan Lake % 115 Thayer Lake % 116 Three Mile Lake % 117 Trumbull Lake % 118 Tuttle Lake % 119 Twelve Mile Creek Lake % 120 Union Grove Lake % 121 Upper Gar Lake % 122 Upper Pine Lake % 123 Viking Lake % 124 Volga Lake % 125 West Okoboji Lake % 126 West Osceola %

31 Table 7. Continued DNR # Lake Year Average 2009 % Change 4 Year to White Oak Lake % 128 Williamson Pond % 129 Willow Lake % 130 Wilson Park Lake % 131 Windmill Lake % 132 Yellow Smoke Park Lake % 29

32 Table 8. Lake Rankings (green shading indicating top 10%, blue shading indicating bottom 10%) DNR # Lake Rank by 4 Year Average Rank by 2009 Rank Change 1 Arbor Lake Arrowhead Lake (Pottawattamie County) Arrowhead Lake (Sac County) Avenue of the Saints Lake Badger Creek Lake Badger Lake Beaver Lake Beeds Lake Big Creek Lake Big Spirit Lake Black Hawk Lake Blue Lake Bob White Lake Briggs Woods Lake Browns Lake Brushy Creek Lake Carter Lake Casey Lake (aka Hickory Hills Lake) Center Lake Central Park Lake Clear Lake Cold Springs Lake Coralville Lake Crawford Creek Impoundment Crystal Lake Dale Maffitt Lake DeSoto Bend Lake Diamond Lake Dog Creek Lake Don Williams Lake East Lake (Osceola) East Okoboji Lake Easter Lake Eldred Sherwood Lake Five Island Lake Fogle Lake George Wyth Lake Green Belt Lake

33 Table 8. Continued DNR # Lake Rank by 4 Year Average Rank by 2009 Rank Change 40 Green Castle Lake Green Valley Lake Greenfield Lake Hannen Lake Hawthorn Lake (aka Barnes City Lake) Hickory Grove Lake Hooper Area Pond Indian Lake Ingham Lake Kent Park Lake Lacey Keosauqua Park Lake Lake Ahquabi Lake Anita Lake Cornelia Lake Darling Lake Geode Lake Hendricks Lake Icaria Lake Iowa Lake Keomah Lake Manawa Lake MacBride Lake Miami Lake Minnewashta Lake of the Hills Lake of Three Fires Lake Orient Lake Pahoja Lake Smith Lake Sugema Lake Wapello Little River Little Sioux Park Lake Little Spirit Lake Little Wall Lake Littlefield Lake Lost Island Lake Lower Gar Lake Lower Pine Lake Manteno Lake

34 Table 8. Continued DNR # Lake Rank by 4 Year Average Rank by 2009 Rank Change 81 Mariposa Lake Meadow Lake Meyers Lake Mill Creek (Lake) Mitchell Lake Moorehead Lake Mormon Trail Lake Nelson Park Lake Nine Eagles Lake North Twin Lake Oldham Lake Otter Creek Lake Ottumwa Lagoon Pierce Creek Lake Pleasant Creek Lake Pollmiller Park Lake Prairie Rose Lake Rathbun Lake Red Haw Lake Red Rock Lake Roberts Creek Lake Rock Creek Lake Rodgers Park Lake Saylorville Lake Silver Lake (Dickinson County) Silver Lake (Worth County) Silver Lake (Delaware County) Silver Lake (Palo Alto County) Slip Bluff Lake South Prairie Lake Spring Lake Springbrook Lake Storm Lake (incl. Little Storm Lake) Swan Lake Thayer Lake Three Mile Lake Trumbull Lake Tuttle Lake Twelve Mile Creek Lake Union Grove Lake

35 Table 8. Continued DNR # Lake Rank by 4 Year Average Rank by 2009 Rank Change 121 Upper Gar Lake Upper Pine Lake Viking Lake Volga Lake West Okoboji Lake West Osceola White Oak Lake Williamson Pond Willow Lake Wilson Park Lake Windmill Lake Yellow Smoke Park Lake

36 34 Figure 1. Map of Iowa Lakes Surveyed

37 Figure 2. Lake Activities Figure 3. Age Distribution 35

38 Figure 4. Employment Status Figure 5. Income Distribution 36

39 Figure 6. Education 37