TCMA Chloride Management Plan - TCMA Chloride Conditions - TMDL summary TCMA Chloride Management Plan - TCMA Chloride Conditions - TMDL summary

The Total Maximum Daily Loads (TMDLs) were developed for each of the lakes, wetlands and streams in the TCMA impaired for chloride, with the exception of Shingle Creek and Nine Mile Creek which already have existing TMDLs. A TMDL quantifies the allowable pollutant loading to a lake, wetland, or stream that will result in water quality standards being attained. The water quality target for the TMDLs was set to the chronic water quality criterion for chloride of 230 mg/L. The total allowable load, or TMDL, is allocated to the various sources contributing chloride as well as consideration of a margin of safety and reserve capacity. Margin of safety is intended to account for uncertainty in the development of the TMDL. Reserve capacity is intended to set-aside a portion of the TMDL for future growth. For the TCMA chloride TMDLs, reserve capacity was set to zero assuming that any further development and additional impervious surfaces would be expected to have the same level of best management practices (BMPs) implemented for winter maintenance activities as for the remainder of the watershed. The complete details of the TMDL development are presented in the TCMA Chloride TMDL report (see Appendix A).

A total of 39 waterbodies are listed as impaired by chloride, and TMDLs for Shingle Creek and Nine Mile Creek have already been prepared under separate projects. A total of 37 TMDLs were completed as part of this project. Summaries of the TMDLs are presented in the following tables.

Summary of TMDL and Components for Impaired Lakes and Wetlands in the TCMA
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Lake/Wetland	AUID	Watershed Area (ac)	TMDL and Components (all values in lbs/yr of chloride)
			Loading Capacity (TMDL	WLA		LA		Margin of Safety
				MS4 Categorical	Wastewater Sources1	Non-Permitted Aggregate	Natural Background
Battle Creek Lake	82-0091-00	4,326	2,153,699	1,766,033	0	0	172,296	215,370
Brownie Lake	27-0038-00	452	341,418	279,963	0	0	27,313	34,142
Carver Lake	82-0166-00	2,242	1,071,123	878,321	0	0	85,690	107,112
Como Lake	62-0055-00	1,850	994,078	815,144	0	0	79,526	99,408
Diamond Lake	27-0022-00	744	486,017	398,534	0	0	38,881	48,602
Kasota Ponds North	62-0280-00	10	6,234	5,112	0	0	499	623
Kasota Ponds West	62-0281-00	6	5,742	4,708	0	0	459	574
Kohlman Lake	62-0006-00	7,533	4,839,183	3,106,733	1,050,484	0	303,096	378,870
Little Johanna Lake	62-0058-00	1,703	1,224,242	1,003,879	0	0	97,939	122,424
Loring Pond (South Bay)	27-0655-02	34	9,764	8,007	0	0	781	976
Mallard Marsh	62-0259-00	16	9,851	8,077	0	0	788	985
Parkers Lake	27-0107-00	1,064	1,431,262	528,161	787,163	0	51,528	64,410
Peavey Lake	27-0138-00	776	205,995	165,889	3,692	0	16,184	20,230
Pike Lake	62-0069-00	5,735	3,591,268	2,943,971	1,059	0	287,217	359,021
Powderhorn Lake	27-0014-00	332	218,588	179,242	0	0	17,487	21,859
Silver Lake	62-0083-00	655	370,011	303,409	0	0	29,601	37,001
South Long Lake	62-0067-02	114,785	26,334,624	21,534,261	4,030	0	2,106,448	2,633,059
Spring Lake	27-0654-00	39	15,600	12,792	0	0	1,248	1,560
Sweeney Lake	27-0035-01	2,439	1,456,271	1,194,142	0	0	116,502	145,627
Tanners Lake	82-0115-00	1,732	826,520	677,746	0	0	66,122	82,652
Thompson Lake	19-0048-00	178	134,340	110,159	0	0	10,747	13,434
Valentine Lake	62-0071-00	2,404	1,165,072	955,359	0	0	93,206	116,507
Wirth Lake	27-0037-00	426	1,095,000	897,900	0	0	87,600	109,500

¹ WLA=0 in the wastewater sources column means that there is no wastewater discharges in that watershed

Summary of TMDL and Components for Impaired Streams in the TCMA
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Stream	AUID	Watershed Area (ac)	TMDL and Components (all values in lbs/yr of chloride)
			Loading Capacity (TMDL	WLA		LA		Margin of Safety
				MS4 Categorical	Wastewater Sources1	Non-Permitted Aggregate	Natural Background
Bass Creek	07010206-784	5,434	1,746,399	1,432,047	0	0	139,712	174,640
Bassett Creek	07010206-538	25,209	9,334,219	6,642,961	1,233,048	0	648,094	810,117
Battle Creek	07010206-592	7,246	2,328,721	1,909,551	0	0	186,298	232,872
Elm Creek	07010206-508	66,382	21,332,410	17,386,888	0	105,688	1,706,593	2,133,241
Judicial Ditch 2	07030005-525	1,587	510,115	418,294	0	0	40,809	51,011
Minnehaha Creek	07010206-539	109,151	35,997,083	28,679,140	1,004,128	0	2,806,140	3,507,675
Raven Stream	07020012-716	42,750	15,023,193	442,771	1,284,983	10,822,561	1,099,057	1,373,821
Raven Stream, East Branch	07020012-543	14,751	6,025,349	442,093	1,284,983	3,445,007	379,229	474,037
Rush Creek, South Fork	07010206-732	13,844	4,470,069	3,646,696	21,010	1,532	355,925	444,906
Sand Creek (South) - includes 07020012-662	07020012-513	175,578	59,480,179	4,402,547	3,056,425	41,864,932	4,513,900	5,642,375
Unnamed creek (Headwaters to Medicine Lk)	07010206-526	6,447	2,071,959	1,699,006	0	0	165,757	207,196
Unnamed creek (Unnamed ditch to wetland)	07010206-718	793	254,852	208,979	0	0	20,388	25,485
Unnamed Stream (Unnamed lk 62-0205-00 to Little Lk Johanna)	07010206-909	1,627	522,817	428,710	0	0	41,825	52,282

¹ WLA=0 in the wastewater sources column means that there is no wastewater discharges in that watershed