U.S. ENVIRONMENTAL PROTECTION AGENCY NATIONAL EUTROPHICATION SURVEY WORKING PAPER SERIES REPORT ON ROCK CREK LAKE JASPER COUNTY IOWA EPA REGION VII WORKING PAPER No, 504 CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON and ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA 699-440 ------- REPORT ON ROCK CREK LAKE JASPER COUNTY IOWA EPA REGION VII WORKING PAPER No, WITH THE COOPERATION OF THE IOWA DEPARTMENT OF ENVIRONMENTAL QUALITY AND THE IOWA NATIONAL GUARD AUGUST, 1376 ------- CONTENTS Page Foreword ii List of Iowa Study Lakes iv Lake and Drainage Area Map v Sections I. Conclusions 1 II. Lake and Drainage Basin Characteristics 3 III. Lake Water Quality Summary 4 IV. Nutrient Loadings 8 V. Literature Reviewed 12 VI. Appendices 13 ------- FOREWORD The National Eutrophication Survey was initiated in 1972 in response to an Administration commitment to investigate the nation- wide threat of accelerated eutrophication to freshwater lakes and reservoirs. OBJECTIVES The Survey was designed to develop, in conjunction with state environmental agencies, information on nutrient sources, concentrations, and impact on selected freshwater lakes as a basis for formulating comprehensive and coordinated national, regional, and state management practices relating to point-source discharge reduction and non-point source pollution abatement in lake watersheds. ANALYTIC APPROACH The mathematical and statistical procedures selected for the Survey's eutrophication analysis are based on related concepts that: a. A generalized representation or model relating sources, concentrations, and impacts can be constructed. b. By applying measurements of relevant parameters associated with lake degradation, the generalized model can be transformed into an operational representation of a lake, its drainage basin, and related nutrients. c. With such a transformation, an assessment of the potential for eutrophication control can be made. LAKE ANALYSIS In this report, the first stage of evaluation of lake and water- shed data collected from the study lake and its drainage basin is documented. The report is formatted to provide state environmental agencies with specific information for basin planning [§303(e)], water quality criteria/standards review [§303(c)], clean lakes [§314(a,b)], and water quality monitoring [§106 and §305(b)] activities mandated by the Federal Water Pollution Control Act Amendments of 1972. ------- m Beyond the single lake analysis, broader based correlations between nutrient concentrations (and loading) and trophic condi- tion are being made to advance the rationale and data base for refinement of nutrient water quality criteria for the Nation's freshwater lakes. Likewise, multivariate evaluations for the relationships between land use, nutrient export, and trophic condition, by lake class or use, are being developed to assist in the formulation of planning guidelines and policies by EPA and to augment plans implementation by the states. ACKNOWLEDGMENT The staff of the National Eutrophication Survey (Office of Research & Development, U. S. Environmental Protection Agency) expresses sincere appreciation to the Iowa Department of Environ- mental Quality for professional involvement, to the Iowa National Guard for conducting the tributary sampling phase of the Survey, and to those wastewater treatment plant operators who voluntarily provided effluent samples and flow data. The staff of the Water Quality Division of the Department of Environmental Quality provided invaluable lake documentation and counsel during the Survey, reviewed the preliminary reports, and provided critiques most useful in the preparation of this Working Paper series. Major General Joseph G. May, the Adjutant General of Iowa, and Project Officer Colonel Cleadeth P. Woods, who directed the volunteer efforts of the Iowa National Guardsmen, are also grate- fully acknowledged for their assistance to the Survey. ------- iv LAKE NAME Ahquabi Big Creek Reservoir Black Hawk Clear Darling Lost Island MacBride Prairie Rose Rathbun Reservoir Red Rock Reservoir Rock Creek Silver Spirit Viking West Okoboji NATIONAL EUTROPHICATION SURVEY STUDY LAKES STATE OF IOWA COUNTY Warren Polk Sac Cerro Gordo Washington Clay, Palo Alto Johnson Shelby Appanoose, Wayne Marion Jasper Worth Dickinson Montgomery Dickinson ------- ROCK CREEK LAKE (^Tributary Sampling Site XLake Sampling Site 3 Drainage Area Boundary i Scale 2 Mi. 4150H 92*54 ------- ROCK CREEK LAKE STORE! NO. 1911 I. CONCLUSIONS A. Trophic Condition: Survey data indicate Rock Creek Lake is eutrophic. It ranked eighth in overall trophic quality when the 15 Iowa water bodies sampled in 1974 were compared using a com- bination of six parameters*. Seven of the water bodies had less median total phosphorus, none of the others had less but one had the same median dissolved phosphorus, ten had less median inorganic nitrogen and mean chlorophyll a_, and 11 had greater mean Secchi disc transparency. Survey limnologists noted beds of aquatic macrophytes along the shore near station 1 in July and an algal bloom at station 1 in September. B. Rate-Limiting Nutrient: The algal assay results show that Rock Creek Lake was phosphorus limited in April and September. The lake data indicate phosphorus limitation at all sampling stations and times. C. Nutrient Controllability: 1. Point sourcesThere were no known point sources impacting Rock Creek Lake during the sampling year. None- theless, the present phosphorus loading of 3.12 g/m2/yr is * See Appendix A. ------- 2 six times that proposed by Vollenweider (Vollenweider and Dillon, 1974) as a eutrophic loading (see page 11). 2. Non-point sourcesThe primary source of phosphorus was Rock Creek which contributed an estimated 64.7% of the total phosphorus load to the lake during the sampling year. The minor tributaries and immediate drainage area contributed an estimated 34.8% of the total load. The phosphorus export rate of Rock Creek was a high 77 kg/km2 during the sampling year. Since no point sources impact the stream, land-use practices must be the cause of the high export rate. In a study of the Iowa Great Lakes, Bachmann and Jones (1973) found the variability in the phosphorus loads in the tributaries was highly correlated with the numbers of animal units (one animal unit = one beef animal) in the respective watersheds, and the 1969 Census of Agriculture (Anonymous, 1973) shows an animal density in the Rock Creek Lake area similar to that in the Iowa Great Lakes area. This suggests that a significant reduction in the Rock Creek phosphorus input may require control of animal wastes. Reportedly, many ducks utilize the main portion of Rock Creek Lake during spring and fall migrations (Anonymous, 1972). However, waterfowl counts are not made routinely (Harrison, 1976), and the significance of nutrient contributions of migrating ducks cannot be determined. ------- II. LAKE AND DRAINAGE BASIN CHARACTERISTICS1" A. Lake Morphometry : 1. Surface area: 2.60 kilometers2. 2. Mean depth: 2.7 meters. 3. Maximum depth: 6.7 meters. 4. Volume: 7.020 x 106 m3. 5. Mean hydraulic retention time: 143 days. B. Tributary and Outlet: (See Appendix C for flow data) 1. Tributaries - Drainage Mean flow Name area (km2)* (m3/sec)* Rock Creek 67.9 0.36 Minor tributaries & immediate drainage - 36.7 0.21 Totals 104.6 0.57 2. Outlet - Rock Creek 107.2** 0.57 C. Precipitation***: 1. Year of sampling: 88.6 centimeters. 2. Mean annual: 87.6 centimeters. t Table of metric conversionsAppendix B. tt Harrison, 1975. * For limits of accuracy, see Working Paper No. 175, "...Survey Methods, 1973-1976". ** Includes area of lake. *** See Working Paper No. 175. ------- 4 III. LAKE WATER QUALITY SUMMARY Rock Creek Lake was sampled three times during the open-water season of 1974 by means of a pontoon-equipped Huey helicopter. Each time, samples for physical and chemical parameters were collected from two or more depths at two stations on the lake (see map, page v). During each visit, a single depth-integrated (near bottom to surface) sample was composited from the stations for phytoplankton identification and enumeration; and during the March and September visits, a single 18.9-liter depth-integrated sample was composited for algal assays. Also each time, a depth-integrated sample was col- lected from each of the stations for chlorophyll a_ analysis. The maximum depths sampled were 4.6 meters at station 1 and 1.5 meters at station 2. The sampling results are presented in full in Appendix D and are summarized in the following table (the July nutrient samples were not preserved properly and were not analyzed). ------- PARAMETER TEMP (C) OISS OXY (MG/U CNDCTVY (HCROMO) PH (STAND UNITS) TOT ALK (MG/L) TOT P (MG/L) ORTHO P (MG/L) N02»N03 (MG/L) AMMONIA (MG/L) KJEL N (MG/L) INORG N (MG/L) TOTAL N (MG/L) CHLRPYL A (UG/L) SECCHI (METERS) A. SUMMARY OF PHYSICAL AND 1ST SAMPLING ( 4/19/74) 2 SITES RANGE MEAN MEDIAN 11.5 - 12.7 12.0 11.7 10.4 - 13.8 11.9 11.4 83. - 225. 146. 161. 8.6 - 8.7 8.7 8.7 136. - 146. 140. 138. 0.061 - 0.071 0.065 0.06S 0.004 - 0.007 0.005 0.005 2.210 - 2.390 2.314 2.320 0.030 - 0.050 0.038 0.040 0.600 - 1.000 O.U40 0.900 2.250 - 2.420 2.352 2.370 2.980 - 3.320 3.154 3.170 24.4 - 34.9 29.6 29.6 0.5 - 0.6 0.5 0.5 CHEMICAL CHARACTERISTICS FOR ROCK CREEK LAKE STORET CODE 1911 2ND SAMPLING ( 7/ 3/74) 2 SITES RANGE 23.6 - 24.8 6.6 - 7.4 368. - 455. 7.8 - 8.0 MEAN MEDIAN 24.1 23.7 6.9 6.8 402. 369. 7.9 7.8 **** _***»**»»*** o _******** ****** _ ****** -»*«»*»«»**** ** .<***»»»****»** »**«* -» <>* _»**»****»**» »» -******* 4.2 - 18.7 11.4 11.4 0.2 - 0.3 0.3 0.3 3RD SAMPLING ( 9/24/74) 2 SITES RANGE MEAN MEDIAN 15.5 - 16.4 16.0 16.3 7.0 - 8.2 7.7 8.0 265. - 337. 321. 333. 7.8 - 8.0 7.9 7.9 192. - 194. 193. 194. 0.056 - 0.073 0.067 0.069 0.008 - 0.013 0.010 0.010 0.280 - 0.310 0.294 0.290 0.240 - 0.260 0.246 0.240 1.000 - 1.600 1.300 1.400 0.520 - 0.550 0.540 0.550 1.310 - 1.880 1.594 1.680 13.5 - 14.5 14.0 14.0 0.4 - 1.0 0.7 0.7 ------- B. Biological characteristics: 1. Phytoplankton - Sampling Date 04/19/74 07/03/74 09/24/74 2. Chlorophyll a_ - Sampling Date 04/19/74 07/03/74 09/24/74 Dominant Genera 1. Cyclotella sp. 2. Flagellates 3. Cryptomonas sp. 4. Chlamydomonas sp. 5. Aphanizomenon sp_. Other genera Total 1. Cryptomonas sp. 2. Centric diatoms 3. Nitzschia sp. 4. Melosira'sp. 5. Lepocinclis sp. Other genera Total 1. Aphanizomenon sp. 2. Cryptomonas sp. 3. Flagellates 4. Chlamydomonas sp. 5. Cruci gem'a sp. Other genera Total Station Number 1 2 1 2 1 2 Algal Units per ml 16,387 712 574 122 52 243 18,090 502 413 325 59 59 118 1,476 4,451 Chlorophyll (ug/D 24.4 34.9 4.2 18.7 14.5 13.5 ------- C. Limiting Nutrient Study: 1. Autoclaved, filtered, and nutrient spiked - a. April sample - Spike (mg/1) Control 0.050 P 0.050 P + 1.0 N 1.0 N b. September sample - Ortho P Cone, (mg/1) Inorganic N Maximum yield Cone, (mg/1) (mg/1-dry wt.) 0.010 0.060 0.060 0.010 2.220 2.220 3.220 3.220 0.2 18.7 16.3 0.2 Spike (mg/1) Control 0.050 P 0.050 P + 1.0 N 1.0 N Ortho P Cone, (mg/1) 0.015 0.065 0.065 0.015 Inorganic N Maximum yield Cone, (mg/1) (mg/1-dry wt.) 0.532 0.532 1.532 1.532 5.0 17.5 30.0 4.9 2. Discussion - The control yield of the assay alga, Selenastrum capri- cornutum, indicates that the potential primary productivity of Rock Creek Lake was low in April but was moderately high in September. The results also indicate that Rock Creek Lake was phosphorus limited at those times. Note that the addition of only phosphorus resulted in a significant increase in yield but no increase in yield occurred with the addition of nitrogen only. The mean lake inorganic nitrogen/orthophosphorus ratios also indicate phosphorus limitation; i. e,. the N/P ratios were 54/1 or greater at all sampling stations and times. ------- 8 IV. NUTRIENT LOADINGS (See Appendix E for data) For the determination of nutrient loadings, the Iowa National Guard collected monthly near-surface grab samples from each of the tributary sites indicated on the map (page v), except for the high runoff months of April and May when two samples were collected. Sampling was begun in August, 1974, and was completed in May, 1975. Through an interagency agreement, stream flow estimates for the year of sampling and a "normalized" or average year were provided by the Iowa District Office of the U.S. Geological Survey for the tributary sites nearest the lake. In this report, nutrient loads for sampled tributaries were determined by using a modification of a U.S. Geological Survey computer program for calculating stream loadings*. Nutrient loads for unsampled "minor tributaries and immediate drainage" ("ZZ" of U.S.G.S.) were esti- mated using the nutrient loads at station A-2, in kg/km2/year, and multiplying by the ZZ area in km2. No known point sources impacted Rock Creek Lake during the sampling year. * See Working Paper No. 175. ------- Waste Sources: 1. Known domestic - Name Rock Creek State Park Pop. Served Mean Flow Treatment (m3/d) stab, ponds ? 2. Known industrial - None Annual Total Phosphorus Loading - Average Year: 1. Inputs - Source kg P/ yr a. Tributaries (non-point load) - Rock Creek 5,255 b. Minor tributaries & immediate drainage (non-point load) - 2,825 c. Known municipal STP's - d. Septic tanks - e. Known industrial - f. Direct precipitation** - 45 Total 8,125 2. Outputs - Lake outlet - Rock Creek 1,450 3. Net annual P accumulation - 6,675 kg. Receiving Water no discharge* % of total 64.7 34.8 0.5 100.0 * Ruchti, 1976. ** See Working Paper No. 175. ------- 10 Annual Total Nitrogen Loading - Average Year: 1. Inputs - Source kg N/ yr a. Tributaries (non-point load) - Rock Creek 58,165 b. Minor tributaries & immediate drainage (non-point load) - 31,450 c. Known municipal STP's - None d. Septic tanks - None e. Known industrial - None f. Direct precipitation* - 2.805 Total 92,420 2. Outputs - Lake outlet - Rock Creek 70,375 3. Net annual N accumulation - 22,045 kg. Non-point Nutrient Export by Subdrainage Area: Tributary kg P/km2/yr Rock Creek 77 % of total 62.9 34.0 3.1 100.0 kg N/kiti2/yr 857 * See Working Paper No. 175. ------- 11 E. Yearly Loads: In the following table, the existing phosphorus loadings are compared to those proposed by Vollenweider (Vollenweider and Dillon, 1974). Essentially, his "dangerous" loading is one at which the receiving water would become eutrophic or remain eutrophic; his "permissible" loading is that which would result in the receiving water remaining oligotrophic or becoming oligotrophic if morphometry permitted. A meso- trophic loading would be considered one between "dangerous" and "permissible". Note that Vollenweider's model may not be applicable to water bodies with short hydraulic retention times. Total Phosphorus Total Nitrogen Total Accumulated Total Accumulated grams/mVyr 3.12 2.57 35.5 8.5 Vollenweider phosphorus loadings (g/m2/yr) based on mean depth and mean hydraulic retention time of Rock Creek Lake. "Dangerous" (eutrophic loading) 0.52 "Permissible" (oligotrophic loading) 0.26 ------- 12 LITERATURE REVIEWED Anonymous, 1972. Rock Creek State Park brochure. IA Cons. Comm., Des Moines. Anonymous, 1973. 1969 Census of Agriculture, vol. 5, part 15. U.S. Dept of Commerce, Wash., DC. Bachmann, R. W., and J. R. Jones, 1973. Relationship between livestock and phosphorus inputs to the Iowa Great Lakes in 1971 and 1972. MS, Dept. Zoo. & Ent., IA St. U., Ames. Harrison, Harry M., 1975. Personal communication (lake morphometry). IA Cons. Comm., Des Moines. , 1976. Personal communication (waterfowl numbers at Rock Creek Lake). IA Cons. Comm., Des Moines. Ruchti, Roger (Park Officer), 1976. Personal communication (waste treatment facilities at Rock Creek State Park). Kellogg. Vollenweider, R. A., and P. J. Dillon, 1974. The application of the phosphorus loading concept to eutrophication research. Natl. Res. Council of Canada Publ. No. 13690, Canada Centre for Inland Waters, Burlington, Ontario. ------- VI. APPENDICES APPENDIX A LAKE RANKINGS ------- LAKE DATA TO BE USED IN RANMNGS LAKE CODE LAKE NAME 1901 LAKE ACGUAdI 1902 BIG CREEK RESERVOIR 1903 BLACK HAWK LAKE 1904 CLEAR LAKE 1905 LAKE DARLING 1906 LOST ISLAND LAKE 1907 LAKE MACBRIOE 1908 PRAIRIE ROSE LAKE 1909 RATHBUN RESERVOIR 1910 RED ROCK LAKE 1911 ROCK CREEK LAKE 1912 SILVER LAKE 1913 SPIRIT LAKE 1914 VIKING LAKE 19J5 WEST LAKE OKOBOJI MEOIAN TOTAL P 0.06? 0.046 0.185 0.059 0.077 0.146 0.061 0.056 0.071 0.180 0.065 0.193 0.041 0.075 0.046 MEOIAN INORG N 0.3J5 6.465 0.130 0.070 1.475 0.065 2.035 0.210 1.170 1.880 1.400 0.565 0.090 0.130 0.060 500- MEAN SEC 469.333 438.500 488.167 465.125 482.500 421.167 458.444 463.667 475.889 473.400 480.500 482.667 422.667 459.000 380.444 MEAN CMLOP.A 8.600 16.867 49.740 17.400 13.817 36.100 17.067 17.350 12.039 14.730 18.367 95.300 12.622 26.033 7.722 15- MIN 00 8.200 14.800 15.000 8.600 9.200 8.400 15.000 8.600 14.000 14.000 8.400 10.000 9.000 14.200 15.000 MEOIAN OISS OKThO P 0.009 0.011 0.020 0.010 0.012 0.021 0.010 0.010 0.008 0.104 0.007 0.034 0.007 0.017 0.017 ------- PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES) LAKE CODE LAKE NAME 1901 LAKE ACOUABI 190? BIG CREEK RESERVOIR 1903 BLACK HAWK LAKE 1904 CLEAR LAKE 1905 LAKE DARLING 1906 LOST ISLAND LAKE 1907 LAKE M4C8RIDE 1908 PRAIRIE ROSE LAKE 1909 RATHBUN RESERVOIR 1910 RED ROCK LAKE 1911 ROCK CREEK LAKE 1912 SILVER LAKE 1913 SPIRIT LAKE 1914 VIKING LAKE 1915 WEST LAKE OKOBOJI MEDIAN TOTAL P 57 ( 89 ( 7 ( 71 ( 29 ( 21 ( 64 < 79 ( 43 ( 1* « 50 ( 0 ( 100 ( 36 ( 89 ( 8) 12) 1) 10) 4) 3) 9) ID 6) 2> 7) 0) 14) 5) 12) MEDIAN INOwG N 50 ( 0 ( 68 < 86 < 21 ( 93 ( 7 ( 57 ( 36 ( 14 ( 29 < 43 ( 79 ( 68 ( 100 ( 7) 0) 9) 12) 3) 13) 1) 8) 5) 2) 4) 6) 11) 9) 14) 500- MEAN SEC 43 ( 79 ( 0 ( 50 ( 14 ( 93 ( 71 ( 57 ( 29 ( 36 ( 21 ( 7 ( 86 ( 64 ( 100 < 6) 11) 0) 7) 2) 13) 10) 8) 4) 5) 3) 1) 12) 9) 14) MEAN CHLORA 93 < 57 ( 7 ( 36 ( 71 ( 14 ( 50 < 43 < 86 ( 64 ( 29 t 0 ( 79 ( 21 ( 100 ( 13) 8) 1) 5) 10) 2) 7) 6) 12) 9) 4) 0) 11) 3) 14) 15- MIN DO 100 ( 21 I 7 ( 75 ( 57 ( 89 ( 7 ( 75 ( 39 ( 39 ( 89 ( 50 ( 64 ( 29 ( 7 ( 14) 3) 0) 10) 8) 12) 0) 10) 5) 5) 12) 7) 9) 4) 0) MEDIAN DISS ORTHO P 79 ( 50 ( 21 ( 64 ( 43 ( 14 ( 64 ( 64 ( 86 ( 0 ( 96 ( 7 ( 96 ( 32 ( 32 < 11) 7) 3) 8) 6) 2) 8) 8) 12) 0) 13) 1) 13) 4) 4) INDEX NO 422 296 110 382 235 32*. 263 375 319 167 314 107 504 250 428 ------- LAKES RANKED BY INDEX NOS. RANK LAKE CODE LAKE NAME INDEX NC 1 1913 SPIRIT LAKE 504 2 1915 WEST LAKE OK080JI 428 3 1901 LAKE ACOUABI 422 4 1904 CLEAR LAKE 382 5 1908 PRAIRIE ROSE LAKE 375 6 1906 LOST ISLAND LAKE 324 7 1909 RATHBUN RESERVOIR 319 8 1911 ROCK CREEK LAKE 314 9 1902 BIG CREEK RESERVOIR 296 10 1907 LAKE MACBRIDE 263 11 1914 VIKING LAKE 250 12 1905 LAKE DARLING 235 13 1910 RED ROCK LAKE 167 14 1903 BLACK HAWK LAKE 110 15 1912 SILVER LAKE 107 ------- APPENDIX B CONVERSION FACTORS ------- CONVERSION FACTORS Hectares x 2.471 = acres Kilometers x 0.6214 = miles Meters x 3.281 = feet -4 Cubic meters x 8.107 x 10 = acre/feet Square kilometers x 0.3861 = square miles Cubic meters/sec x 35.315 = cubic feet/sec Centimeters x 0.3937 = inches Kilograms x 2.205 = pounds Kilograms/square kilometer x 5.711 = Ibs/square mile ------- APPENDIX C TRIBUTARY FLOW DATA ------- TRIBUTARY FLOW INFORMATION FOR IOWA 12/23/75 LAKE CODE 1911 ROCK CREEK RES. SUB-DRAINAGE TRIBUTARY AREA(SO KM) 1911A1 1911A2 1911ZZ 107.2 67.9 39.4 OF LAKE (SO KH) 107, JAN 0.28 0.17 0.10 FEB 0.87 0.55 0.32 MAR 1.40 0.89 0.52 .2 APR 0.78 0.50 0.29 MAY 0.91 0.57 0.33 NORMALIZED FLOWS(CMS) JUN JUL AUG 1.07 0.68 0.39 0.62 0.39 0.23 0. 0. 0. 21 13 08 SEP 0.20 0.13 0.07 OCT NOV 0.21 0.22 0.13 0.14 0.08 0.08 DEC MEAN 0.15 0.57 0.09 0.36 0.05 0.21 SUMMARY OTAL ;UM OF DRAINAGE AREA OF LAKE ' SUB-DRAINAGE AREAS = 107.2 107.2 TOTAL TOTAL FLOW FLOW IN « OUT => 6.93 6.93 MEAN MONTHLY FLOWS AND DAILY FLOWS(CMS) TRIBUTARY MONTH YEAR MEAN FLOW DAY 1911A1 1911A2 1911ZZ 8 9 10 11 12 1 2 3 4 S 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 74 74 74 74 74 75 75 75 75 75 75 75 74 74 74 74 74 75 75 75 75 75 75 75 74 74 74 74 74 75 75 75 75 75 75 75 0.23 0.07 0.08 0.28 0.34 0.22 0.16 1.22 0.85 0.48 1.02 0.40 0.16 0.05 0.05 0.21 0.22 0.14 0.10 0.76 0.54 0.31 0.71 0.27 0.09 0.03 0.03 0.12 0.13 0.08 0.06 0.45 0.31 0.18 0.42 0.16 17 14 19 16 13 11 22 16 5 18 17 14 19 16 13 11 22 16 5 18 FLOW DAY FLOW DAY FLOW 0.18 0.07 0.06 0.27 0.34 .20 .18 .31 .65 .42 0.13 0.05 0.04 0.19 0.22 0.12 0.11 0.20 0.40 0.26 19 25 19 25 0.68 0.37 0.42 0.23 ------- APPENDIX D PHYSICAL and CHEMICAL DATA ------- STORET RETRIEVAL DATE 75/13/23 191101 41 44 27.0 092 51 20.0 ROCK CREEK LAKE 19 IOWA 11EPALES 4 2111202 0020 FEET DEPTH DATE FROM TO 74/04/19 74/07/03 74/09/24 DATE FROM TO 74/04/19 74/07/03 74/09/24 TIME DEPTH OF DAY FEET 16 00 0000 16 00 0005 16 00 0015 09 30 0000 09 30 0005 09 30 0012 09 30 0000 09 30 0005 09 30 0014 TIME DEPTH OF DAY FEET 16 00 0000 16 00 0005 16 00 0015 09 30 0000 09 30 0004 09 30 0000 09 30 0001 09 30 0005 09 30 0006 09 30 0014 00010 WATER TEMP CENT 11.7 11.5 11.5 23.7 23.7 23.6 16.4 16.4 16.3 00665 PHOS-TOT MG/L P 0.064 0.061 0.071 0.056 0.064 0.072 00300 DO MG/L 11.4 10.4 6.B 6.6 6.6 7.4 7.0 6.0 32217 CHLRPHYL A UG/L 24.4 4.2 14.5 00077 TRANSP SECCHI INCHES 25 12 40 00031 INCDT LT REMNING PERCENT 1.0 50.0 1.0 FIELD 194 :TVY i IMHO 83 161 225 369 369 368 337 265 337 00400 PH su 8.70 8.65 8.60 7.80 7.80 7.80 7.85 7.89 7.87 00410 T ALK CAC03 MG/L 138 137 136 194 194 192 00610 NH3-N TOTAL MG/L 0.050 0.040 0.040 0.260 0.240 0.240 00625 TOT KJEL N MG/L 1.000 0.800 0.600 1.400 1.000 1.100 00630 N021N03 N- TOTAL MG/L 2.320 2.210 2.360 0.290 0.310 0.310 00671 PHOS-DIS ORTHO MG/L P 0.007 0.005 0.007 0.012 0.009 0.010 ------- STORET RETRIEVAL DATE 75/13/23 191102 41 46 30.0 092 50 ROCK CREEK LAKE 19 IOMA 15.0 DATE FROM TO 74/04/19 74/07/03 74/09/24 TIME DEPTH OF DAY FEET 16 15 0000 16 15 0005 09 55 0000 09 55 0003 10 00 0000 10 00 0005 00010 WATER TEMP CENT 12.7 12.6 24.8 24.7 15.6 15.5 00300 00077 00094 00 TRANSP CNDUCTVY SECCHI FIELD MG/L INCHES MICROMHO 13.8 7.2 7.4 8.2 8.0 18 8 14 91 168 455 450 333 333 11EPALES 4 00400 PH SU 8.70 8.70 8.00 7.90 8.02 8.03 00410 T ALK CAC03 MG/L 146 145 193 194 2111202 0007 00610 NH3-N TOTAL MG/L 0.030 0.030 0.250 0.240 FEET DEPTH 00625 TOT KJEL N MG/L 0.900 0.900 1.600 1.400 00630 N02&N03 N-TOTAL MG/L 2.270 2.390 0.280 0.280 00671 PHOS-DIS ORTHO MG/L P 0.004 0.004 0.006 0.013 0066S DATE TIME DEPTH PHOS-TOT FROM OF TO DAY FEET MG/L P 74/04/19 16 15 0000 0.065 16 15 0005 0.066 74/07/03 09 55 0000 74/09/24 10 00 0000 0.073 10 00 0001 10 00 0005 0.069 10 00 0006 32217 00031 CHLRPHYL INCDT LT A REMNING UG/L PERCENT 34.9 18.7 13.5 SO.O 1.0 ------- APPENDIX E TRIBUTARY DATA ------- STORET RETRIEVAL DATE 76/01/37 1911A1 41 43 20.0 092 51 00.0 HOCK CREEK 19125 JASPER CO HWY MP 0/ROCK CREEK RESERVOIR BRDG JUST S OF ROCK CREEK STATE PARK HEP ALES 2111204 4 0000 FEET DEPTH DATE FROM TO 74/08/17 74/09/14 74/10/19 74/11/16 74/12/13 75/01/11 75/02/22 75/03/16 75/04/05 75/04/19 75/05/05 75/05/25 TIME DEPTH OF DAY FEET 15 20 14 10 14 00 13 30 12 50 10 15 14 00 14 00 14 30 13 15 13 30 00630 N02&N03 N-TOTAL MG/L 1.680 0.490 0.240 0.480 0.768 1.160 2.760 1.500 1.570 1.570 1.600 1.500 00625 TOT KJEL N MG/L 1.100 1.000 0.600 1.500 1.200 1.700 0.100 1.050 1.850 2.000 1.150 0.700 00610 NH3-N TOTAL MG/L 0.095 0.050 0.060 0.270 0.348 0.352 0.085 0.270 0.825 0.720 0.085 0.100 00671 PHOS-DIS ORTHO MG/L P 0.010 0.015 0.015 0.015 0.015 0.020 0.023 0.010 0.030 0.030 0.075 0.005 00665 PHOS-TOT MG/L P 0.045 0.055 0.030 0.070 0.040 0.050 0.040 0.060 0.090 0.100 0.075 0.040 ------- STORET RETRIEVAL DATE 76/01/27 1911A2 41 49 00.0 092 50 00.0 ROCK CREEK 19 JASPER CO HWY MP T/ROCK CHEEK RESERVOIR BRDG JUST N OF ROCK CREEK STATE PARK 11EPALES 2111204 4 0000 FEET DEPTH DATE FROM TO 74/08/17 74/09/14 74/10/19 74/11/16 74/12/13 75/01/11 75/02/22 75/03/16 75/04/05 75/04/19 75/05/16 75/05/25 TIME DEPTH OF DAY FEET 15 50 13 45 13 47 13 50 13 15 10 35 14 15 14 25 14 55 13 25 13 40 00630 N02&N03 N-TOTAL MG/L 4.700 2.880 2.640 4.700 4.700 3.680 2.610 2.300 1.600 4.800 4.200 4.200 00625 TOT KJEL N MG/L 0.600 0.900 0.700 0.600 0.900 1.900 0.100K 1.180 1.650 3.750 1.050 1.250 00610 NH3-N TOTAL MG/L 0.035 0.045 0.090 0.075 0.100 0.432 0.024 0.175 0.780 0.150 0.070 0.030 00671 PHOS-DIS ORTHO MG/L P 0.055 0.040 0.035 0.040 0.035 0.065 0.044 0.040 0.030 0.070 0.050 0.045 00665 PHOS-TOT MG/L P 0.110 0.110 0.080 0.180 0.140 0.300 0.046 0.140 0.310 0.800 0.440 0.260 K VALUE KNOWN TO BE LESS THAN INDICATED ------- |