Agenda packet — Beaumont City Council, June 17, 2025 (part 16 of 21)

WHEREAS, on September 18, 2018, the City Council adopted Ordinance No. 1103 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within CFD 2018-1 (Fund Code 68-0208).

WHEREAS, on March 5, 2019, the City Council adopted Ordinance No. 1105 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within CFD 2019 -1 (Fund Code 68-0209, 68-0210 & 68-0211).

WHEREAS, on June 15, 2021, the City Council adopted Ordinance No. 1133 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within CFD 2021 -1 (Fund Code 68-0425, 68-0426 & 68-0427).

WHEREAS, on July 18, 2023, the City Council adopted Ordinance No. 1161 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within CFD 2023-1 (Fund Code 68-0533, 68-2533, 68-0534 & 68- 0535).

NOW THEREFORE BE IT RESOLVED, by the City Council of the City of Beaumont as follows:

Section 1: The preceding recitals are true and correct.

Section 2: The City of Beaumont hereby determined to Levy the Special Taxes in the Fiscal Year 2025-2026 (and each subsequent Fiscal Year) in Improvement Area No's. 1-7 (including 6A ), 10-12, 6A1, 7B, 7C, 7D, 7A1, 8, 8A -D, 8F, 13, 14A, 15, 16, 17A -D, 19A, 19C, 20, and 23 of CFD 93-1 and CFDs 2016-1, 2016-2, 2016-3, 2016-4, 2018-1, 2019-1, 2021-1 & 2023-1 and to each parcel therein, as provided in the schedule of Special Taxes, a copy of which has been presented to the City Council and lodged with the City Clerk.

Section 3: The rate of each Special Tax utilized in the preparation of the Report does not exceed the amount previously authorized by Ordinance and is not in excess of that approved by the qualified electors of the applicable Districts and Improvement Areas.

Section 4: As to a District and/or an Improvement Area, the proceeds of the Special Tax shall be used to pay, in whole or in part and as applicable, the costs of the following for the subject Fiscal Year as provided in the City of Beaumont Community Facilities District No. 93-1 Indenture of Trusts and the City of Beaumont CFDs 2016-1, 2016-2, 2016-3, 2016-4, 2018-1, 2019-1, 2021-1 & 2023-1 Indenture of Trust (collectively the 'Indenture of Trust'):

A. The Administrative costs and other incidental expenses of the applicable District and/or Improvement Area; and
B. The Interest scheduled for collection on the outstanding bonded indebtedness related to the applicable District and/or Improvement Area; and C. The principal scheduled for collection on the outstanding bonded indebtedness related to the applicable District and/or Improvement Area; and

Page 20113 of 2775 ends

D. The sinking payments scheduled for collection on the outstanding bonded indebtedness relating to the applicable District and/or Improvement Area; and E. Amounts, if any, needed to replenish the applicable Reserve Account of the Bond Fund to the level of the Reserve Requirement; and
F. Amounts, if any, required to bring the amount on deposit in the Rebate Fund to the required level; and
G. Amounts for approved services.

Section 5: The Auditor -Controller of the County of Riverside is hereby directed to apply to each real property statement for each parcel in such County in the applicable District and/or Improvement Area for the Fiscal Year listing the Special Tax due opposite each parcel of land affected, in a line item designated "CFD Special Tax," or any other suitable designation, in accordance with this Resolution.

Section 6: All Special Taxes collected will be paid to the trustee for deposit in the applicable Special Tax fund upon receipt by the City of Beaumont from the Auditor- Controller pursuant to the terms of the Indenture of Trust.

Section 7: The Auditor -Controller shall, at the close of the tax collection period, promptly render to the Director a detailed report showing the amounts of Special Tax installments, penalties, interest, and fees collected, and from which properties collected. Any expenses to be paid to the Auditor -Controller for carrying out the forgoing responsibilities shall be in accordance with a contract, if any, entered into between the District and the Auditor -Controller, pursuant to Section 29304 of the Government Code of the State of California or as otherwise provided by law.

Section 8: This resolution shall take effect immediately upon its passage and adoption.

MOVED, PASSED, and ADOPTED this 17th day of June, 2025, by the following vote:

AYES:

NOES:

ABSTAIN:

ABSENT:

APPROVED:

Mike Lara, Mayor
ATTEST:

Nicole Wheelwright, Deputy City Clerk

Page 204 of 2775 ends

RESOLUTION NO. 2025-

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF

BEAUMONT, CALIFORNIA, LEVYING THE SPECIAL TAX IN
COMMUNITY FACILITIES DISTRICT NO. 93-1 (IA 14 & 14B) AND

DIRECTING THE COUNTY AUDITOR TO COLLECT THE SAME ON
1'HE TAX ROLLS
(IA 14 & 14B)
WHEREAS, Council Member David Fenn has recused himself from any participation related to this Resolution;
WHEREAS, The City Council (the "City Council") of the City of Beaumont is the legislative body of Community Facilities District No. 93-1 ('District'), which District was established pursuant to the provisions of the Mello -Roos Community Facilities Act of 1982, as amended, being Chapter 2.5, Part 1, Division 2, Title 5 of the Government C ode of the State of California (the "Act"); and WHEREAS, on June 29, 1993, the City Council adopted Resolution 1993- 13 establishing the District, including separate improvement areas therein including Improvement Area 14 and 14B (singly or collectively "Improvement Area") and providing for the Special Tax within each such Improvement Area; a n d WHEREAS, on January 11, 2000, the City Council adopted Ordinance No. 800 in accordance the Section 53340 of the Act authorizing the levy of Special Tax on the property located within Improvement Area No. 14. (Fund Code 68-2122 & 68-2125); and
WHEREAS, on November 5, 2002 the City Council adopted Ordinance No. 836 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within Improvement Area 14B. (Fund Code 68-2182).

NOW THEREFORE BE IT RESOLVED, by the City Council of the City of Beaumont as follows:

Section 1: The preceding recitals are true and correct.

Section 2: The City of Beaumont hereby determined to Levy the Special Taxes in the Fiscal Year 2025-2026 (and each subsequent Fiscal Year) in Improvement Area Nos. 14 and 14B and to each parcel therein, as provided in the schedule of Special Taxes, a copy of which has been presented to the City Council and lodged with the City Clerk.

Section 4: As to the District and/or an Improvement Area, the proceeds of the

Page 20715 of 2775 ends

Special Tax shall be used to pay, in whole or in part and as applicable, the costs of the following for the subject Fiscal Year as provided in the City of Beaumont Community Facilities District No. 93-1 Indenture of Trusts (the 'Indenture of Trust'):

A. The Administrative costs and other incidental expenses of the Improvement Area and/or District; and
B. The Interest scheduled for collection on the outstanding bonded indebtedness related to the applicable Improvement Area and/or District; and C. The principal scheduled for collection on the outstanding bonded indebtedness related to the applicable Improvement Area and/or District; and D. The sinking payments scheduled for collection on the outstanding bonded indebtedness relating to the applicable Improvement Area and/or District; and E. Amounts, if any, needed to replenish the applicable Reserve Account of the Bond Fund to the level of the Reserve Requirement; and
F. Amounts, if any, required to bring the amount on deposit in the Rebate Fund to the required level; and
G. Amounts for approved services.

Section 5: The Auditor -Controller of the County of Riverside is hereby directed to apply to each real property statement for each parcel in such County in the applicable Improvement Areas of the District for the Fiscal Year listing the Special Tax due opposite each parcel of land affected, in a line item designated "CFD Special Tax," or any other suitable designation, in accordance with this Resolution.

Section 8: This resolution shall take effect immediately upon its passage and adoption.

MOVED, PASSED, and ADOPTED this 17th day of June, 2025, by the following vote:

AYES:

NOES:

ABSTAIN:

ABSENT:

Page 206 of 2775 ends

RECUSED: Fenn
APPROVED:

Mike Lara, Mayor
ATTEST:

Nicole Wheelwright, Deputy City Clerk
3

Page 2077 of 2775 ends

RESOLUTION NO. 2025-

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF

BEAUMONT, CALIFORNIA, LEVYING THE SPECIAL TAX IN
COMMUNITY FACILITIES DISTRICT NO. 93-1 (IA 9) AND DIRECTING

THE COUNTY AUDITOR TO COLLECT THE SAME ON THE TAX
ROLLS
(IA 9)
WHEREAS, Council Member Julio Martinez recused himself from any participation in this Resolution;
WHEREAS, The City Council (the "City Council") of the City of Beaumont is the legislative body of Community Facilities District No. 93-1 ('District'), which district was established pursuant to the provisions of the Mello -Roos Community Facilities Act of 1982, as amended, being Chapter 2.5, Part 1, Division 2, Title 5 of the Government Code of the State of California (the "Act"); and WHEREAS, on June 29, 1993 the City Council adopted Resolution 1993- 13 establishing the District, including separate improvement areas therein (the 'Improvement Areas") and providing for the Special Tax within such Improvement Area; and
WHEREAS, on August 11, 1993, the City Council enacted Ordinance No. 721 in accordance with Section 53340 of the Act authorizing the levy of the Special Tax on the property located within Improvement Area No. 9 of the District ("Improvement Area"). (Fund Code (68-2116 & 68-2124).

NOW THEREFORE BE IT RESOLVED, by the City Council of the City of Beaumont as follows:

Section 1: The preceding recitals are true and correct.

Section 2: The City of Beaumont hereby determines to Levy the Special Taxes in the Fiscal Year 2025-2026 (and each subsequent Fiscal Year) in Improvement Area No. 9 and to each parcel therein, as provided in the schedule of Special Taxes, a copy of which has been presented to the City Council and lodged with the City Clerk.

Section 4: As to the District and/or Improvement Area, the proceeds of the Special Tax shall be used to pay, in whole or in part and as applicable, the costs of the following for the subject Fiscal Year as provided in the City of Beaumont Community Facilities District No. 93-1 Indenture of Trusts ('Indenture of Trust'):

A. The Administrative costs and other incidental expenses of the Improvement Area and/or District; and

Page 20718 of 2775 ends

B. The Interest scheduled for collection on the outstanding bonded indebtedness related to the Improvement Area and/or District; and
C. The principal scheduled for collection on the outstanding bonded indebtedness related to the Improvement Area and/or District; and
D. The sinking payments scheduled for collection on the outstanding bonded indebtedness relating to the Improvement Area and/or District; and E. Amounts, if any, needed to replenish the applicable Reserve Account of the Bond Fund to the level of the Reserve Requirement; and
F. Amounts, if any, required to bring the amount on deposit in the Rebate Fund to the required level; and
G. Amounts for approved services.

Section 5: The Auditor -Controller of the County of Riverside is hereby directed to apply to each real property statement for each parcel in such County in the applicable Improvement Area of the District for the Fiscal Year listing the Special Tax due opposite each parcel of land affected, in a line item designated "CFD Special Tax," or any other suitable designation, in accordance with this Resolution.

Section 8: This resolution shall take effect immediately upon its passage and adoption.

MOVED, PASSED, and ADOPTED this 17th day of June, 2025, by the following vote:

AYES:

NOES:

ABSTAIN:

ABSENT:

RECUSED: Martinez

Page 207 ends

APPROVED:

Mike Lara, Mayor
ATTEST:

Nicole Wheelwright, Deputy City Clerk
3

Page 2080 of 2775 ends

RESOLUTION NO. 2025-

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF

BEAUMONT, CALIFORNIA, LEVYING THE SPECIAL TAX IN
COMMUNITY FACILITIES DISTRICT NO. 93-1 (IA 8E) AND

DIRECTING THE COUNTY AUDITOR TO COLLECT THE SAME ON
1`HE TAX ROLLS
(IA 8E)
WHEREAS, Council Member Jessica Voigt has recused herself from any participation related to this Resolution;
WHEREAS, The City Council (the "City Council") of the City of Beaumont is the legislative body of Community Facilities District No. 93-1 ('District"), which District was established pursuant to the provisions of the Mello -Roos Community Facilities Act of 1982, as amended, being Chapter 2.5, Part 1, Division 2, Title 5 of the Government C ode of the State of California (the "Act"); and WHEREAS, on June 29, 1993 the City Council adopted Resolution 1993- 13 establishing the District, including separate improvement areas therein including Improvement Area 8E (the "Improvement Area") and providing for the Special Tax within such Improvement Area; and
WHEREAS, on July 21, 2015 the City Council adopted Ordinance No. 1056 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within Improvement Area 8E. (Fund Code 68-2104 & 68-2161).

NOW THEREFORE BE IT RESOLVED, by the City Council of the City of Beaumont as follows:

Section 1: The preceding recitals are true and correct.

Section 2: The City of Beaumont hereby determined to Levy the Special Taxes in the Fiscal Year 2025-2026 (and each subsequent Fiscal Year) in Improvement Area No. 8E and to each parcel therein, as provided in the schedule of Special Taxes, a copy of which has been presented to the City Council and lodged with the City Clerk.

Section 4: As to the District and/or an Improvement Area, the proceeds of the Special Tax shall be used to pay, in whole or in part as applicable, the costs of the following for the subject Fiscal Year as provided in the City of Beaumont Community Facilities District No. 93-1 Indenture of Trusts (the 'Indenture of Trust'):

A. The Administrative costs and other incidental expenses of the Improvement Area and/or District; and

Page 208 ends

B. The Interest scheduled for collection on the outstanding bonded indebtedness related to the applicable Improvement Area and/or District; and C. The principal scheduled for collection on the outstanding bonded indebtedness related to the applicable Improvement Area and/or District; and D. The sinking payments scheduled for collection on the outstanding bonded indebtedness relating to the applicable Improvement Area and/or District; and E. Amounts, if any, needed to replenish the applicable Reserve Account of the Bond Fund to the level of the Reserve Requirement; and
F. Amounts, if any, required to bring the amount on deposit in the Rebate Fund to the required level; and
G. Amounts for approved services.

Section 5: The Auditor -Controller of the County of Riverside is hereby directed to apply to each real property statement for each parcel in such County in the applicable Improvement Area of the District for the Fiscal Year listing the Special Tax due opposite each parcel of land affected, in a line item designated "CFD Special Tax," or any other suitable designation, in accordance with this Resolution.

Section 8: This resolution shall take effect immediately upon its passage and adoption.

MOVED, PASSED, and ADOPTED this 17th day of June, 2025, by the following vote:

AYES:

NOES:

ABSTAIN:

ABSENT:

RECUSED: Voigt

Page 2082 of 2775 ends

APPROVED:

Mike Lara, Mayor
ATTEST:

Nicole Wheelwright, Deputy City Clerk
3

Page 2083 of 2775 ends

RESOLUTION NO. 2025-

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF

BEAUMONT, CALIFORNIA, LEVYING THE SPECIAL TAX IN
COM1VIUNITY FACILITIES DISTRICT NO. 93-1 (IA 18) AND

DIRECTING THE COUNTY AUDITOR TO COLLECT THE SAME ON
1'HE TAX ROLLS
(IA 18)
WHEREAS, Council Member Lloyd White has recused himself from any participation related to this Resolution;
WHEREAS, The City Council (the "City Council") of the City of Beaumont is the legislative body of Community Facilities District No. 93-1 ('District"), which District was established pursuant to the provisions of the Mello -Roos Community Facilities Act of 1982, as amended, being Chapter 2.5, Part 1, Division 2, Title 5 of the Government C ode of the State of California (the "Act"); and WHEREAS, on June 29, 1993 the City Council adopted Resolution 1993- 13 establishing the District, including separate improvement areas therein including Improvement Area 18 (the "Improvement Area") and providing for the Special Tax within such Improvement Area; and
WHEREAS, on February 3, 2004 the City Council adopted Ordinance No. 853 in accordance with Section 53340 of the Act authorizing the levy of Special Tax on the property located within Improvement Area 18. (Fund Code 68-2097 & 68- 2132).

NOW THEREFORE BE IT RESOLVED, by the City Council of the City of Beaumont as follows:

Section 1: The preceding recitals are true and correct.

Section 2: The City of Beaumont hereby determined to Levy the Special Taxes in the Fiscal Year 2025-2026 (and each subsequent Fiscal Year) in Improvement Area No. 18 and to each parcel therein, as provided in the schedule of Special Taxes, a copy of which has been presented to the City Council and lodged with the City Clerk.

A. The Administrative costs and other incidental expenses of the Improvement Area and/or District; and

Page 20844 of 2775 ends

Section 5: The Auditor -Controller of the County of Riverside is hereby directed to apply to each real property statement for each parcel in such County in the applicable Improvement Area of the District for the Fiscal Year listing the Special Tax due opposite each parcel of land affected, in a line item designated "CFD Special Tax," or any other suitable designation, in accordance with this Resolution.

Section 8: This resolution shall take effect immediately upon its passage and adoption.

MOVED, PASSED, and ADOPTED this 17th day of June, 2025, by the following vote:

AYES:

NOES:

ABSTAIN:

ABSENT:

RECUSED: White

Page 20825 of 2775 ends

APPROVED:

Mike Lara, Mayor
ATTEST:

Nicole Wheelwright, Deputy City Clerk
3

Page 2086 of 2775 ends

ATTACHMENT F

SUMMARY OF CFD SPECIAL TAX ENROLLMENT
FISCAL YEAR 2025-2026
Fund
Number
District Name
FY 2025-26
Proposed Parcels
FY 2024-25
Actual Levy
FY 2025-26
Proposed Levy
Bond
Maturity
District
Maturity*
68-2111
CFD No. 93-1 IA 3
511
$243,297
$246,066
9/1/2032
6/30/2044
68-2123
CFD No. 93-1 IA 3 SERVICE
511
$209,990
$216,147
N/A
Perpetuity
68-2114
CFD No. 93-1 IA 6A
2 $7,481
$7,552
N/A
6/30/2044
68-2183
CFD No. 93-1 IA 6A1
953
$2,392,871
$2,392,874
9/1/2035
6/30/2050
68-2088
CFD No. 93-1 IA 6A1 SERVICE
954
$376,029
$387,051
N/A
Perpetuity
68-1811
CFD No. 93-1 IA 7A1
484
$707,935
$709,954
9/1/2045
6/30/2050
68-1812
CFD No. 93-1 IA 7A1 SERVICE
537
$211,621
$217,832
N/A
Perpetuity
68-2139
CFD No. 93-1 IA 7B
231
$295,918
$298,127
9/1/2039
6/30/2050
68-2095
CFD No. 93-1 IA 7B SERVICE
283
$111,525
$114,798
N/A
Perpetuity
68-2146
CFD No. 93-1 IA 7C
318
$135,016
$134,251
9/1/2039
6/30/2050
68-2094
CFD No. 93-1 IA 7C SERVICE
391
$154,085
$158,608
N/A
Perpetuity
68-2179
CFD No. 93-1 IA 7D
296
$234,676
$236,297
9/1/2048
6/30/2056
68-2180
CFD No. 93-1 IA 7D SERVICE
296
$116,760
$120,186
N/A
Perpetuity
68-2127
CFD No. 93-1 IA 8
944
$673,374
$671,543
9/1/2032
6/30/2043
68-2129
CFD No. 93-1 TA 8 SERVICE
946
$382,638
$393,868
N/A
Perpetuity
68-2136
CFD No. 93-1 IA 8A
408
$518,705
$519,757
9/1/2035
6/30/2046
68-2101
CFD No. 93-1 TA 8A SERVICE
178
$72,197
$74,313
N/A
Perpetuity
68-2140
CFD No. 93-1 IA 8B
192
$455,821
$455,779
9/1/2037
6/30/2050
68-2102
CFD No. 93-1 TA 8B SERVICE
192
$77,660
$79,939
N/A
Perpetuity
68-2141
CFD No. 93-1 IA 8C
686
$1,605,367
$1,639,066
9/1/2048
6/30/2051
68-2149
CFD No. 93-1 IA 8C SERVICE
689
$278,769
$286,944
N/A
Perpetuity
68-2147
CFD No. 93-1 IA 8D
279
$491,716
$501,496
9/1/2048
6/30/2051
68-2150
CFD No. 93-1 TA 8D SERVICE
279
$112,883
$116,194
N/A
Perpetuity
68-2104
CFD No. 93-1 IA 8E
372
$722,450
$735,674
9/1/2048
6/30/2056
68-2161
CFD No. 93-1 IA 8E SERVICE
372
$157,110
$161,714
N/A
Perpetuity
68-2162
CFD No. 93-1 IA 8F
294
$658,712
$674,087
9/1/2050
6/30/2056
68-2163
CFD No. 93-1 IA 8F SERVICE
294
$124,168
$127,807
N/A
Perpetuity
68-2116
CFD No. 93-1 IA 9
69 $58,455
$60,450
9/1/2032
6/30/2044
68-2124
CFD No. 93-1 IA 9 SERVICE
69 $17,180
$17,684
N/A
Perpetuity
68-2117
CFD No. 93-1 IA 10A
146
$168,528
$168,785
9/1/2032
6/30/2044
68-2126
CFD No. 93-1 TA l0A SERVICE
147
$36,600
$37,675
N/A
Perpetuity
68-2118
CFD No. 93-1 IA 11
140
$117,299
$119,323
9/1/2032
6/30/2044
68-2121
CFD No. 93-1 TA 11 SERVICE
140
$37,551
$38,653
N/A
Perpetuity
68-2119
CFD No. 93-1 IA 12A
106
$117,300
$119,323
9/1/2032
6/30/2044
68-2130
CFD No. 93-1 TA 12A SERVICE
108
$43,684
$44,966
N/A
Perpetuity
68-2120
CFD No. 93-1 IA 13 SERVICE
107
$47,178
$48,562
N/A
Perpetuity
68-2122
CFD No. 93-1 IA 14
1,897
$639,569
$644,061
9/1/2032
6/30/2037
68-2125
CFD No. 93-1 IA 14 SERVICE
1,940
$709,263
$730,054
N/A
Perpetuity
68-2181
CFD No. 93-1 IA 14A
1,249
$1,137,035
$1,139,418
9/1/2033
6/30/2044
68-2182
CFD No. 93-1 IA 14B
310
$307,421
$308,083
9/1/2037
6/30/2044
68-2128
CFD No. 93-1 TA 15 SERVICE
71 $30,372
$31,263
N/A
Perpetuity
68-2134
CFD No. 93-1 IA 16
240
$605,715
$603,646
9/1/2034
6/30/2044
68-2093
CFD No. 93-1 IA 16 SERVICE
241
$94,973
$97,761
N/A
Perpetuity
68-2131
CFD No. 93-1 IA 17A
483
$753,264
$757,285
9/1/2034
6/30/2044
68-2090
CFD No. 93-1 IA 17A SERVICE
488
$192,311
$197,955
N/A
Perpetuity
68-2142
CFD No. 93-1 IA 17B
388
$738,718
$737,297
9/1/2042
6/30/2051
68-2089
CFD No. 93-1 TA 17B SERVICE
390
$153,707
$158,211
N/A
Perpetuity
68-2144
CFD No. 93-1 IA 17C
215
$514,863
$525,024
9/1/2048
6/30/2057
68-2098
CFD No. 93-1 TA 17C SERVICE
216
$89,048
$91,660
N/A
Perpetuity
68-0531
CFD No. 93-1 IA 17D
268
$550,849
$565,981
9/1/2054
6/30/2056
68-0532
CFD No. 93-1 TA 17D SERVICE
268
$120,615
$125,085
N/A
Perpetuity
68-2132
CFD No. 93-1 IA 18
193
$414,784
$415,979
9/1/2034
6/30/2044
68-2097
CFD No. 93-1 IA 18 SERVICE
194
$76,452
$78,695
N/A
Perpetuity
68-2135
CFD No. 93-1 IA 19A
542
$1,543,079
$1,546,343
9/1/2035
6/30/2044
68-2096
CFD No. 93-1 TA 19A SERVICE
599
$233,095
$239,932
N/A
Perpetuity
68-2137
CFD No. 93-1 IA 19C
667
$1,643,037
$1,613,406
9/1/2036
6/30/2044
68-2099
CFD No. 93-1 IA 19C SERVICE
669
$265,820
$273,612
N/A
Perpetuity
68-2143
CFD No. 93-1 IA 20
106
$250,730
$251,416
9/1/2035
6/30/2044

Page 2087 of 2775 ends

Fund
Number
District Name
FY 2025-26
Proposed Parcels
FY 2024-25
Actual Levy
FY 2025-26
Proposed Levy
Bond
Maturity
District
Maturity*
68-2091
CFD No. 93-1 IA 20 SERVICE
106
$42,118
$43,353
N/A
Perpetuity
68-2138
CFD No. 93-1 IA 23 SERVICE
65 $29,673
$30,542
N/A
Perpetuity
68-1818
CFD No. 2016-1
372
$587,090
$587,604
9/1/2049
6/30/2056
68-1819
CFD No. 2016-1 SERVICE
372
$146,620
$150,917
N/A
Perpetuity
68-0045
CFD No. 2016-2
527
$674,220
$675,442
9/1/2049
6/30/2056
68-0046
CFD No. 2016-2 PUBLIC SERVICE
527
$302,466
$317,590
N/A
Perpetuity
68-0043
CFD No. 2016-2 SERVICE
527
$216,207
$222,543
N/A
Perpetuity
68-0204
CFD No. 2016-3
704
$896,734
$1,024,185
9/1/2053
6/30/2056
68-0206
CFD No. 2016-3 PUBLIC SERVICE
615
$323,128
$370,622
N/A
Perpetuity
68-0205
CFD No. 2016-3 SERVICE
615
$54,780
$61,603
N/A
Perpetuity
68-0047
CFD No. 2016-4
346
$278,643
$275,061
9/1/2049
6/30/2057
68-0048
CFD No. 2016-4 PUBLIC SERVICE
346
$198,583
$208,513
N/A
Perpetuity
68-0049
CFD No. 2016-4 SERVICE
346
$30,261
$31,150
N/A
Perpetuity
68-0208
CFD No. 2018-1 PUBLIC SERVICE
981
$557,928
$591,257
N/A
Perpetuity
68-0209
CFD No. 2019-1
118
$147,416
$150,436
9/1/2050
6/30/2056
68-0211
CFD No. 2019-1 PUBLIC SERVICE
118
$67,732
$71,120
N/A
Perpetuity
68-0210
CFD No. 2019-1 SERVICE
118
$39,281
$40,432
N/A
Perpetuity
68-0425
CFD No. 2021-1
529
$1,043,370
$1,052,995
9/1/2054
6/30/2062
68-0427
CFD No. 2021-1 PUBLIC SERVICE
529
$300,577
$318,620
N/A
Perpetuity
68-0426
CFD No. 2021-1 SERVICE
529
$118,602
$123,243
N/A
Perpetuity
68-0533
CFD No. 2023-1 IA 1
132
$123,136
$177,845
N/A
6/30/2064
68-2533
CFD No. 2023-1 IA 2
287
$394,750
$529,630
N/A
6/30/2064
68-0535
CFD No. 2023-1 PUBLIC SERVICE
419
$160,866
$235,131
N/A
Perpetuity
68-0534
CFD No. 2023-1 SERVICE
419
$131,591
$188,553
N/A
Perpetuity
Total
34,205
$30,103,042
$30,943,903
* Perpetuity means as long as the City provides the Services.

Page 2088 of 2775 ends

FY 2025 - 2026 _

Page 2089 of 2775 ends

CONSULTING GROUP

Discussion
• Each year the Council approves the annual enrollment resolutions. The FY 2025 — 2026 Special Tax Levy includes:
33 Improvement Areas of CFD 93-1
CFD's 2016-1, 2016-2, 2016-3, 2016-4, 2018-1, 2019-1, 2021-1, & 2023-1 • The Special Taxes collected each year are used to pay for the following:

Annual debt service on bonds
Costs of providing maintenance service
Costs of providing public safety
Administration costs
Collection of Future Facilities funds

Page 2090 of 2775 ends

Discussion (cont.)
There are approximately 34,205 separate charges for the proposed enrolment on 15,968 individual parcels within the City
Budget Line Items
Debt Service Payment
Maintenance Services
Public Safety Services
Administrative Expenses
Delinquency Reserve
Future Facility
Total Expenses
FY 2024-25
Actual
$20,160,279
$4,979,926
$1,814,064
$1,396,945
$257,029
$1,308,676
$29,916,919
FY 2025-26
Proposed
$21,134,792
$5,187,521
$2,066,398
$1,406,701
$286,619
$771,980
$30,854,012
Total Change
$974,513
$207,595
$252,334
$9,756
$29,590
($536,696)
$937,092
% Change

4.83%

4.17%

13.91%

0.70%

11.51%
-41.01%

3.13%

Page 2091 of 2775 ends

Fiscal Impact
• The fiscal impact on the City's general fund is indirect, as the administration and maintenance portions of assessments collected are the funding source for the administration of the CFD processes and maintenance of the various applicable geographic regions.

Page 2092 of 2775 ends

Recommended Action
• Waive the full reading and adopt by title only "A Resolution of the City Council of the City of Beaumont, California, Levying the Special Tax in Community Facilities Districts No. 93-1, 2016-1, 2016-2, 2016-3, 2016-4, 2018-1, 2019-1, 2021-1, and 2023-1 and Directing the County Auditor to Collect the Same on the Tax Rolls (93- 1, 2016-1, 2016-2, 2016-3, 2016-4, 2018-1, 2019-1, 2021-1, and 2023-1)." • Waive the full reading and adopt by title only "A Resolution of the City Council of the City of Beaumont, California, Levying the Special Tax in Community Facilities Districts No. 93-1(IA 18) and Directing the County Auditor to Collect the Same on the Tax Rolls (IA 18)."
• Waive the full reading and adopt by title only "A Resolution of the City Council of the City of Beaumont, California, Levying the Special Tax in Community Facilities Districts No. 93-1(IA 14 and 14B) and Directing the County Auditor to Collect the Same on the Tax Rolls (IA 14 and 14B)."
• Waive the full reading and adopt by title only "A Resolution of the City Council of the City of Beaumont, California, Levying the Special Tax in Community Facilities Districts No. 93-1(IA 9) and Directing the County Auditor to Collect the Same on the Tax Rolls (IA 9)."
•
Waive the full reading and adopt by title only "A Resolution of the City Council of the City of Beaumont, California, Levying the Special Tax in Community Facilities Districts No. 93-1(IA 8E) and Dirigctie fn ef ty Auditor to Collect the Same on the Tax Rolls (IA 8E)." ag o

Thank you
Questions?

BEAUMONT
-C A L I F O R N I A
Staff Report
TO: City Council
FROM: Thaxton Van Belle, Director of Water Reclamation
DATE June 17, 2025
SUBJECT: Adaptive Management and Mitigation Plan (AMMP) Update - Provide Direction on the Quantity of Recycled Water to Pursue — Capital Improvement Project No. WW -14
Description: Strategic Plan Target 4.1. Phase one of the Adaptive Management and Mitigation Plan (AMMP) is complete, and direction is needed to pursue the study's initial supported quantity of recycled water, or to pursue addition quantities, resulting in increased costs and timeline.

Background and Analysis:

The City has initiated plans to reduce the discharge of treated wastewater (i.e., recycled water) from the Beaumont Wastewater Treatment Plant (WWTP) to Cooper's Creek and divert that water for other beneficial uses. To reduce the volume of discharge to Cooper's Creek, the City must file a Wastewater Change Petition (Change Petition) under California Water Code Section 1211 with the State Water Resources Control Board (SWRCB), Division of Water Rights.

City Staff and representatives of the City Council met with Division of Water Rights staff to discuss the process and tips for success. The Division of Water Rights staff advised that the City develop an Adaptive Management and Mitigation Plan (AMMP) to facilitate the approval process for the reduced discharge prior to filing the Change Petition.

An AMMP ensures there is a plan and program in place to assess and mitigate, if necessary, any riparian habitat impacts that result from reducing the WWTP discharge to Cooper's Creek. The AMMP defines the monitoring, adaptive triggers, and mitigation measures implemented to manage the effects of reduced discharge to Cooper's Creek and San Timoteo Creeks.

On August 15, 2023, the City awarded a professional services agreement to Tom Dodson & Associates to prepare an AMMP. The first phase of the project involved characterizing both historical and current conditions to support the development of the AMMP. This first phase has been completed, and a report has been issued

Page 2095 of 2775 ends

(Attachment A). Based on the analyses and conclusions in the Phase 1 report, a reduced discharge of 1.7 million gallons per day (MGD) would likely sustain groundwater levels and maintain the health of riparian habitats. A reduced discharge below 1.7 MGD would require additional analysis to support the potential impact.

Before the second phase can begin, which consists of a feasibility assessment incorporating the findings from the first phase and continued baseline monitoring, direction is needed on which reduced discharge scenario to pursue:
• Scenario 1 - Reduce discharge to 1.7 MGD.
• Scenario 2 - Explore a discharge lower than 1.7 MGD.

Considerations:
• Scenario 1:
o Requires implementation of the baseline monitoring program and CEQA. o Timeline of approximately two years with incremental reductions to discharge flow.
o Increased monitoring costs of approximately $415,000*. o Volume supported by the Phase 1 report.
o Aligns with the 1.8 MGD value established in the treatment plant discharge permit.
• Scenario 2:
o Requires implementation of the baseline monitoring program and CEQA. o Requires modeling of the hydrologic system and its response to a suite of reduced discharges.
o Timeline of approximately two years with incremental reductions to discharge flow and one year for modeling, or a total of three years. o Increased monitoring costs of approximately $415,000, plus $565,000 in modeling, or $980,000*.
o Potential increase in available recycled water.
o No guarantee of additional volume.
*Note: Monetary values are taken from the 02/14/25 Tech Memo with Rough Order of Magnitude (ROM) costs. No additional funding is being requested at this time. Once a scenario to pursue is selected, staff will bring forward a change order for Council consideration.

Fiscal Impact:

The estimated cost to prepare this report is $750.

Page 2096 of 2775 ends

The AMMP (Project WW -14) is currently funded by Recycled Water DIF funds, and no direct fiscal impacts are associated with this item. Currently, there are sufficient Recycled Water DIF funds to pursue either of the presented scenarios.

Recommended Action:

Direct staff to pursue Scenario 1, reduction of discharge to 1.7 MGD.

Attachments:

A. AMMP Phase 1 Report
B. Tech Memo
C. Presentation Slides

Page 2097 of 2775 ends

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

PREPARED FOR
City of Beaumont

BEAUMONT

A L I F O R N I A

PREPARED BY
wi

WEST I YOST
P e 20 2775 Water. Engineered.

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report
Prepared for
City of Beaumont
Project No. 1113-80-23-01
May 21, 2025
Prepared by: Clay Sorensen, CHG, CHG#1108
Prepared by: Veva earner
4/QUReview: Samantha Adams
Yv

WEST I YOST
Water. Engineered.

Date
May 21, 2025
Date
May 21, 2025
Date
FINAL REPORT I MAY 2025

1.0 Introduction 1

1.1 Adaptive Management and Mitigation Plan (AMMP) 1

1.2 Scope to Develop AMMP 1

1.3 Report Outline 2

2.0 Background and Setting 4

2.1 Current and Historical Operations of the WWTP 4

2.2 Regulatory Setting 6

2.2.1 Regional Water Quality Control Board Requirements 6

2.2.2 State Water Resource Control Board Requirements 8

2.2.3 Existing Monitoring and Reporting Programs 8

2.2.3.1 Maximum Benefit Monitoring Program 9

2.2.3.2 Beaumont WWTP NPDES Permit Monitoring 9

2.2.3.3 SAWA Biological Monitoring 9

2.2.4 Water Rights 9

2.3 Physical Setting 11

2.3.1 Surface Water Hydrology 11

2.3.1.1 Surface Water Bodies 11

2.3.1.2 Climate and Precipitation 11

2.3.2 Geologic Setting 14

2.3.2.1 Local Geologic Setting 14

2.3.2.2 Geologic Structure 14

2.3.3 Hydrogeologic Setting 14

2.3.3.1 Water Bearing Formations 15

2.3.3.2 Groundwater Occurrence and Flow 15

2.3.3.3 Groundwater Age and Quality 15

3.0 Initial Goals, Objective, and Performance Criteria 17

3.1 Goals and Objectives 17

3.2 Performance Criteria 18

4.0 Historical and Existing Biological Resources 19

4.1 Regional Ecological Setting 19

4.1.1 Regional Riparian Ecology 19

4.2 Historical Biological Resources 22

4.2.1 Cooper's Creek 22

4.2.1.1 Riparian Plant Communities 22

4.2.1.2 Wildlife 23

4.2.2 San Timoteo Creek 25

4.2.2.1 Riparian Plant Communities 25

4.2.2.2 Wildlife 25

4.3 Existing Biological Resources 27

4.3.1 Methods 28

WEST YOST

Page 2100 of 2775 ends

City of Beaumont
May 2025

4.3.1.1 Vegetation Sampling Surveys 28

4.3.1.2 General Inventory of Biological Resources 38

4.3.1.3 Focused Protocol Surveys 38

4.3.2 Cooper's Creek 38

4.3.2.1 Riparian Plant Communities 38

4.3.2.2 Wildlife 54

4.3.3 San Timoteo Creek 55

4.3.3.1 Riparian Plant Communities 55

5.0 Historical Riparian Habitat Health (NDVI) 70

5.1 Overview of NDVI Analysis 70

5.2 Overview of Riparian Zone, Study Segments, and Focus Areas 71

5.3 Temporal Analysis of NDVI 72

5.3.1 Cooper's Creek 1 Segment and Focused Areas (FA01 to FA06) 75

5.3.2 San Timoteo 1 Segment and Focused Areas (FA07 and FA08). 76

5.3.3 San Timoteo 2 Segment and Focused Areas (FA09 and FA10) 77

5.3.4 Conclusions from Temporal Analysis 77

6.0 Hydrologic Characterization 89

6.1 WWTP Discharges 89

6.2 Surface Water 91

6.2.1 Surface Water Flows 91

6.2.2 Surface Water Quality 94

6.2.2.1 Nitrate as Nitrogen 94

6.2.2.2 Total Dissolved Solids (TDS) 97

6.3 Groundwater Levels 98

6.3.1 Groundwater Elevation Time Series 98

6.3.2 Groundwater Flow System 99

6.3.3 Depth to Groundwater 99

6.4 Groundwater Quality 102

6.4.1 Nitrate 102

6.4.2 Total Dissolved Solids 105

7.0 Factors that Impact Riparian Habitat 106

7.1 Surface Water Flows 106

7.1.1 Cooper's Creek 1 Segment 108

7.1.2 San Timoteo 1 Segment 109

7.1.3 San Timoteo 2 Segment 111

7.1.4 Summary 113

7.2 Groundwater Levels 113

7.2.1 Cooper's Creek 1 Segment 114

7.2.2 San Timoteo 1 Segment 114

7.2.3 San Timoteo 2 Segment 115

WEST YOST

Page 2101 of 2775 ends

City of Beaumont
May 2025

7.2.4 Summary 115

7.3 Hydrological Impacts to Biological Resources 119

7.3.1 Surface Water 119

7.3.2 Groundwater 119

7.4 Other Climate Factors 120

7.5 Wildfires 121

7.6 Invasive Species and Pests 121

7.7 Data Gaps 123

7.7.1 Riparian Vegetation Data 123

7.7.2 Groundwater Level Data 123

7.7.3 Surveyed Elevations of Reference Points and Thalweg 124

7.7.4 Frequency of Surface Water Flow Measurements 124

8.0 Baseline Monitoring and Data Collection Program 126

8.1 Riparian Habitat Monitoring 126

8.1.1 Remote Sensing 126

8.1.2 Drone Surveys 126

8.1.3 Ground Surveys 128

8.2 Surface Water Monitoring 128

8.3 Groundwater Monitoring 131

8.4 Reference Point and Thalweg Elevation Surveys 131

8.5 Climate 132

8.6 Feasibility of Reduced Discharge 132

8.7 Implementation and Reporting 133

9.0 Conclusions and Performance Criteria 134

9.1 Conclusions 134

9.2 Performance Criteria 135

10.0 References 137

LIST OF TABLES
Table 2-1. Summary of Water Quality Objectives 7
Table 4-1a. Sample Area 1- Salix laevigata Forest & Woodland Alliance Percent Cover by Species .. 32 Table 4-1b. Percent Native and Non-native Cover within Sample Area 1 33 Table 4-1c. Native Species Richness within Sample Area 1 33 Table 4-2a. Sample Area 2 - Salix gooddingii - Salix laevigata Forest & Woodland Alliance Percent Cover by Species 34
Table 4-2b. Percent Native and Non-native Cover within Sample Area 2 35

WEST YOST
ni

Page 2102 of 2775 ends

City of Beaumont
May 2025

Table of Contents
r
Table 4-2c. Native Species Richness within Sample Area 2 35 Table 4-3a. Sample Area 3 - Salix gooddingii Forest & Woodland Alliance Percent Cover by Species 36 Table 4-3b. Percent Native and Non-native Cover within Sample Area 3 37 Table 4-3c. Native Species Richness within Sample Area 3 37 Table 4-4. List of Plant Species Observed 50
Table 4-5. List of Wildlife Species Observed 51
Table 5-1. Mann -Kendall Test Results of the Average -Growing Season NDVI Trends for Defined Areas in the Cooper's and San Timoteo Creeks 73 Table 5-2. Characterization of Variability in the Average -Growing Season NDVI for Defined Areas in the Study Area 74
Table 6-1. Historical WWTP Discharges 90
Table 8-1. Hydrogeological Baseline Monitoring Program Enhanced Monitoring Locations 130

LIST OF FIGURES
Figure 2-1. Study Area and Water Quality Objectives Map 5 Figure 2-2. Hydrogeological Monitoring Locations — Beaumont and Upper San Timoteo GMZs 10 Figure 2-3. Hy6drologic and Hydrogeologic Features of the Timoteo Watershed 12 Figure 2-4. Annual Precipitation in the San Timoteo Watershed — Water Year 1895 - 2023 13 Figure 4-1. Baseline Vegetation Sample Area 1 29
Figure 4-2. Baseline Vegetation Sample Area 2 30
Figure 4-3. Baseline Vegetation Sample Area 3 31
Figure 4-4a. Cooper's Creek Riparian Plant Communities 40 Figure 4-4b. Cooper's Creek Riparian Plant Communities 41 Figure 4-4c. Cooper's Creek Riparian Plant Communities 42 Figure 4-4d. Cooper's Creek Riparian Plant Communities 43 Figure 4-4e. Cooper's Creek Riparian Plant Communities 44 Figure 4-4f. Cooper's Creek Riparian Plant Communities 45 Figure 4-4g. Cooper's Creek Riparian Plant Communities 46 Figure 4-4h. Cooper's Creek Riparian Plant Communities 47 Figure 4-4i. Cooper's Creek Riparian Plant Communities 48 Figure 4-4j. Cooper's Creek Riparian Plant Communities 49 Figure 4-5a. San Timoteo Creek Riparian Plant Communities 56 Figure 4-5b. San Timoteo Creek Riparian Plant Communities 57

WEST YOST
Iv

Page 2103 of 2775 ends

City of Beaumont
May 2025

able of Conten
s
r
Figure 4-5c. San Timoteo Creek Riparian Plant Communities 58 Figure 4-5d. San Timoteo Creek Riparian Plant Communities 59 Figure 4-5e. San Timoteo Creek Riparian Plant Communities 60 Figure 4-5f. San Timoteo Creek Riparian Plant Communities 61 Figure 4-5g. San Timoteo Creek Riparian Plant Communities 62 Figure 4-5h. San Timoteo Creek Riparian Plant Communities 63 Figure 4-5i. San Timoteo Creek Riparian Plant Communities 64 Figure 4-5j. San Timoteo Creek Riparian Plant Communities 65 Figure 4-5k. San Timoteo Creek Riparian Plant Communities 66 Figure 4-51. San Timoteo Creek Riparian Plant Communities 67 Figure 4-5m. San Timoteo Creek Riparian Plant Communities 68 Figure 5-1. Riparian Zone, Study Segments, and Focus Areas 79 Figure 5-2. Focus Areas FA01, FA02, FA03, FA04, and FA05 for NDVI Analysis 80 Figure 5-3. Focus Areas FA06, FA07, and FA08 for NDVI Data Analysis 81 Figure 5-4. Focus Areas FA09, FA10, and FA11 for NDVI Data Analysis 82 Figure 5-5a. Time Series of NDVI for Cooper's Creek 1 Segment 83 Figure 5-5b. Time Series of NDVI for Focus Areas along Cooper's Creek 1 84 Figure 5-6a. Time Series of NDVI for San Timoteo 1 Segment 85 Figure 5-6b. Time Series of NDVI for Focus Areas along San Timoteo 1 86 Figure 5-7a. Time Series of NDVI for San Timoteo 2 Segment 87 Figure 5-7b. Time Series of NDVI for Focus Areas along San Timoteo 2 88 Figure 6.1. Daily Effluent Discharge to Cooper's Creek and San Timoteo Creek at Beaumont WWTP DP -001 and Henry N Wochholz RWRF DP -001 92
Figure 6-2. Surface Water Flows at Select Surface Water Monitoring Locations 93 Figure 6-3. Nitrate -Nitrogen Concentrations in Surface Water 95 Figure 6-4. TDS Concentrations in Surface Water 96
Figure 6-5. Groundwater Elevations at Select Well Locations 100 Figure 6-6. Groundwater Elevation Spring 2022 101
Figure 6-7. Nitrate -Nitrogen Concentrations in Groundwater 103 Figure 6-8. TDS Concentrations in Groundwater 104
Figure 7-1. Precipitation, Surface Water Flow, and WWTP Discharge versus NDVI, Cooper's Creek 1 Segment for 1983-2023 107
Figure 7-2. Precipitation, Surface Water Flow, and WWTP Discharge versus NDVI, San Timoteo 1 Segment for 1983-2023 110

WEST YOST
v

Page 2104 of 2775 ends

City of Beaumont
May 2025

Table of Contents
Figure 7-3. Precipitation, Surface Water Flow, and WWTP Discharge versus NDVI, San Timoteo 2 Segment for 1983-2023 112
Figure 7-4. Groundwater Levels and WWTP Discharge versus NDVI, Cooper's Creek 1 Segment for 1983-2023 116
Figure 7-5. Groundwater Levels and WWTP Discharge versus NDVI, San Timoteo 1 Segment for 1983-2023 117
Figure 7-6. Groundwater Levels and WWTP Discharge versus NDVI, San Timoteo 2 Segment for 1983-2023 118
Figure 8-1. Riparian Baseline Monitoring and Data Collection Locations 127 Figure 8-2. Hydrogeological Baseline Monitoring and Data Collection Locations 129

LIST OF APPENDICES
Appendix A. Draft Technical Memorandum, Initial Goals, Objectives and Performance Criteria for the City of Beaumont Adaptive Management and Mitigation Program (AMMP), December 21, 2023
Appendix B. Letter, Least Bell's Vireo and Southwestern Willow Flycatcher Survey Results for the City of Beaumont, Cooper's Creek Wastewater Discharge Study, November 5, 2024 Appendix C. Normalized Differences Vegetation Index (NDVI) Appendix D. Mann -Kendall Analysis of NDVI

WEST YOST
vi

Page 2105 of 2775 ends

City of Beaumont
May 2025

LIST OF ACRONYMS AND ABBREVIATIONS
afy Acre -Feet Per Year
AMMP Adaptive Management and Mitigation Program
BCVWD Beaumont Cherry Valley Water District
CDFM Cumulative departure from the mean
CDFW California Department of Fish and Wildlife
Cfs Cubic Feet Per Second
Change Petition Wastewater Change Petition
City City of Beaumont
CIWQS California Integrated Water Quality System
CNDDB California Natural Diversity Database
COYE Common Yellowthroat
CSPA Center Science Processing Architecture
DEM Digital elevation Model
EROS Earth Resources Observation and Science
FA Focus Area
ft Feet
Ft bgs Feet Below Ground Surface
ft2/day Square Feet Per Day
GMZ Groundwater management zones
GNSS Global Navigation Satellite System
LBVI Least Bell's Vireo
M Meter
MBR Membrane bioreactor
mgd Million gallons per day
mgl Milligrams per liter
NAVD88 North American Vertical Datum
NDVI Normalized Difference Vegetation Index
NPDES National Pollutant Discharge Elimination System
RGB Red, Green, and Blue
RHJV Riparian Habitat Joint Venture
RO Reverse osmosis
RWRF Regional Water Recycling Facility
SARI Santa Ana Regional Interceptor
SAWA Santa Ana Watershed Association
SAWPA Santa Ana Watershed Project Authority
SC Specific Conductance
SMWD South Mesa Water Company
SNMP Salt and nutrient management plan
SOSP Song Sparrow
SSC Species of Special Concern
SWRCB State Water Resources Control Board

WEST YOST

Page 2106 of 2775 ends

City of Beaumont
May 2025

Table of Conten
s
r
TDA
TDS
TIN
USFWS
USGS
UV
VegCAMP
Watershed
WIFL
WIWA

WRC-MSHCP
WWTP
YBCH
YBCU
YEWA
YVWD
Tom Dodson & Associates
Total Dissolved Solids
Total inorganic nitrogen
U.S. Fish and Wildlife Service
United States Geological Survey
Ultraviolet
Vegetation Classification and Mapping Program
San Timoteo Watershed
Willow Flycatcher
Wilson's Warbler
Western Riverside County Multiple Species Habitat Conservation Plan Wastewater Treatment Plant
Yellow -Breasted Chat
Western yellow -billed cuckoo
Yellow Warbler
Yucaipa Valley Water District

WEST YOST
viii

Page 2107 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report
This Cooper's Creek and San Timoteo Creek Habitat Characterization and Sustainability Report (Report) was prepared in conjunction with HDR1 for the City of Beaumont (City or Beaumont) to support their efforts to reduce recycled water discharges and prepare an Adaptive Management and Mitigation Plan (AMMP) for the riparian habitat along Cooper's Creek and San Timoteo Creek.

1.0 INTRODUCTION
This section describes: 1) the need for the City to develop an AMMP for the riparian habitat along Cooper's Creek and San Timoteo Creek; 2) the scope of work to develop the AMMP; and 3) the organization of this report.

1.1 Adaptive Management and Mitigation Plan (AMMP)
The City has initiated plans to reduce the discharge of treated wastewater (i.e. recycled water) from the Beaumont Wastewater Treatment Plant (WWTP) to Cooper's Creek, and divert that water for other beneficial uses. To reduce the volume of discharge to Cooper's Creek, the City must file a Wastewater Change Petition (Change Petition) under California Water Code Section 1211 with the State Water Resources Control Board (SWRCB), Division of Water Rights. When the City first discussed the plan to apply for a change petition with Division of Water Rights staff, they advised that the City develop an AMMP to aid in the process of approving the reduced discharge.

An AMMP is required to ensure there is a plan and program in place to assess and mitigate, if necessary, any riparian habitat impacts that result from reducing the WWTP discharge to Cooper's Creek. The AMMP defines the monitoring, adaptive triggers, and mitigation measures put in place to manage the effects of a reduced discharge to the Cooper's and San Timoteo Creeks.

The City contracted with Tom Dodson & Associates (TDA), West Yost, and HDR (collectively referred to as the Consultant Team) to develop the AMMP and support the change petition process.

1.2 Scope to Develop AMMP
The AMMP is being developed in three phases, as follows:
• Phase 1— Characterize historical and current conditions to support development of the AMMP • Phase 2 — Assess the feasibility of reduced discharge and perform initial baseline monitoring • Phase 3 — Prepare the AMMP
HDR Biologists assisted with the preparation of Section 4, Section 7, Section 8, and Section 9.

WEST YOST

Page 2108 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
-CA IFURNI,-
This report documents the results of Phase 1 and is the initial AMMP. The objective of Phase 1 was to characterize the historical and current conditions of the study area in support of the development of the AMMP. This was completed through the following tasks and steps:
• Task 1— Project management and meetings
• Task 2 — Establish initial goals, objectives, and project performance criteria • Task 3 — Characterize historical discharge and surface water flow hydrology • Task 4 — Characterize historical riparian habitat health (NDVI) • Task 5 — Characterize historical and existing biological resources • Task 6 — Identify potential impacts to biological resources from reduced discharge to Cooper's Creek
• Task 7 —Assess available tools for analyzing surface water and groundwater impacts2 • Task 8 — Prepare Cooper's Creek and San Timoteo Creek Habitat Characterization and Sustainability Report

1.3 Report Outline
This Report summarizes the work completed during Phase 1 of the AMMP. The Report includes a description of the background and setting of the study area region and the Beaumont WWTP operations, characterizes historical data and information on the riparian habitat and hydrology, and a proposed baseline monitoring program reduced discharge of treated water to Cooper's Creek.

This Report is organized under the following sections:
• Section 1— Introduction. This section provides an overview and purpose of the AMMP. • Section 2 — Background and Setting. This section describes the history of the WWTP and its physical and regulatory setting.
• Section 3 — Initial Goals, Objectives, and Performance Criteria. This section describes the City's goals, objectives, and performance criteria for the development of the AMMP. • Section 4 — Historical and Existing Biological Resources. This section characterizes the historical and existing biological resources in the study area. • Section 5 — Historical Riparian Habitat Health. This section characterizes the historical health of the riparian habitat in the study area based on multiple data sources. • Section 6 — Historical Discharge, Surface Water Flow Hydrology, and Groundwater Characterization. This section characterizes the historical hydrology of the Cooper's and San Timoteo Creeks, groundwater, and discharges.
2The assessment of available modeling tools for analyzing surface water and groundwater impacts is not included in this report. The available tools were identified and reviewed to the extent possible, however the Beaumont Basin Groundwater Model was not made available in time to complete the assessment for this report. The Task 7 scope will be completed in 2025 and the findings provided under separate cover. Any recommendations will be incorporated in the next adaptation of the AMMP.

WEST YOST
2

Page 2109 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
• Section 7 — Potential Impacts to Biological Resources from Reduced Discharge to Cooper's Creek. This section describes the potential impacts to the riparian habitat that could result from reducing the City's WWTP discharge to Cooper's Creek and identifies data gaps in the understanding of the study area biologic and hydrogeologic setting. • Section 8 —Initial Baseline Monitoring and Data Collection Plan. This section describes the biologic and hydrogeologic baseline monitoring and data collection program that the City should perform prior to reducing its discharge to Cooper's Creek. • Section 9 — Summary and Conclusions. This section summarizes the Report and its conclusions.
• Section 10 — References. This section contains a list of references cited in the Report.

WEST YOST
3

Page 2110 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

2.0 BACKGROUND AND SETTING
This section describes the 1) background on the current and historical operations of the Beaumont WWTP and its discharges, 2) regulatory setting of the WWTP, and 3) the physical setting of the AMMP (i.e. the "Study Area").

Figure 2-1 is a location map of the region showing the AMMP Study Area, the City jurisdictional boundary, local surface water steams and tributaries, WWTP discharge locations, and other jurisdictional and hydrological boundaries referenced herein. The Study Area includes the riparian habitat and adjacent areas along Cooper's Creek and San Timoteo Creek. The Study Area begins on Cooper's Creek just upstream of the Beaumont WWTP discharge location DP001 and continues northwest and downstream along Cooper's Creek and San Timoteo Creek, terminating at the site of the Henry N Wochholz Regional Water Recycling Facility (RWRF) discharge, which is operated by the Yucaipa Valley Water District (YVWD).

2.1 Current and Historical Operations of the WWTP
The City, located in Riverside County, owns and operates the Beaumont WWTP. The Beaumont WWTP is the only treatment plant for the City, which serves a population of approximately 53,000 people as of 2020 (US Census, 2020). The Beaumont WWTP receives and treats domestic and commercial/industrial wastewater generated within the City boundaries and Highland Springs, which is a portion of the unincorporated area of Cherry Valley. The treated wastewater is discharged to Cooper's Creek, which is a tributary to San Timoteo Creek. According to the City, discharge to Cooper's Creek from the original Beaumont WWTP began sometime in the 1920s. The WWTP and discharge operations have been modified over time with population growth and changing regulations. The discharge volume from the WWTP began to increase significantly around 2004, concurrent with rapid development throughout the City's service area.

In 2018, the City began construction to upgrade treatment at the Beaumont WWTP to add advanced treatment using a combination of membrane bioreactor (MBR), reverse osmosis (RO), and ultraviolet (UV) treatments (termed RO system). Operation of the RO system commenced in November 2020, and further upgrades to the RO system were completed at the end of 2022 with full operation in 2023. All water treated via the RO System is discharged to Cooper's Creek at rates generally ranging between 3.0 and

4.1 million gallons per day (mgd). Fewer fluctuations in the daily discharge are expected compared to past discharge operations due to the requirement to operate the RO system at more constant flow rates.

Brine waste generated from the RO system is pumped through a City -owned brine line approximately 23 miles in length that connects to the Inland Empire Brine Line, which was previously referred to as the Santa Ana Regional Interceptor (SARI) line. The Inland Empire Brine Line is owned and operated by the Santa Ana Watershed Project Authority (SAWPA) and pumps high -saline water to a wastewater treatment plant operated by the Orange County Sanitation District.

Currently, treated wastewater from the Beaumont WWTP is discharged via one outfall to Cooper's Creek:

Discharge Point 001 (DP001 or DP -001). Cooper's Creek flows into San Timoteo Creek approximately three miles downstream of DP001. San Timoteo Creek flows into the Santa Ana River approximately 16 miles downstream in the City of San Bernardino. Historically, two additional wastewater discharge points were permitted within the City's limits: DP007 to an unnamed tributary of Marshall Creek and DP008 to Noble Creek. The City only operated outfall DP007 from March 2010 to August 2015 and there is no record of discharges to outfall DP008. YVWD also discharges treated wastewater to San Timoteo Creek from the Henry N Wochholz RWRF DP001.

WEST YOST
4

Page 2111 of 2775 ends

City of Beaumont
May 2025

Prepared by:

Prepared for:
an iimotec
400/5.0
300 / 2.7
41/

WEST I YOST
Yucaipa
I i
milk .
i • Beaumont
...
i .._.._..1 /.•% , .• :WWTP DP 008
• \ •�, /.� I_..1 •
(Inactive)
i
oo,r � _ _ _ -- -' B▪ e
aumont
eaumont
Pk `•_ _ San Timoteo Creek WWTP DP 007
0 (Inactive)
6,000
Beaumont
WWTP [ iP 001.
12,006
Feet

Page 2112 of 2775 ends

Beaumont
330/5.0
230 / 1.5
City of Beaumont
Adaptive Management and
Mitigation Plan (AMMPJ BEAUM0N1
— — - Streams
•
O
City of Beaumont
Study Area
Beaumont WWTP Boundary
Adjudicated Basin Boundary
San Timoteo GMZ
Yucaipa GMZ
Beaumont GMZ
San Timoteo Watershed Boundary
WWTP Discharge Point (active)
WWTP Discharge Point (inactive)
Geology
Water -Bearing Sediments
Unconsolidated to Semi -consolidated Quaternary
Alluvium
Consolidated and Semi -Consolidated Formations
San Timoteo Formation
NIUndifferentiated Pre -Tertiary Igneous and
Metamorphic Crystalline Rocks
GMZ maximum benefit (top values) and
antidegradation (bottom values) water quality
objectives for TDS (left values) and nitrate as
nitrogen (right values)
Beaumont
330 / 5.0
230 / 1.5
Notes:

1. GMZ - groundwater management zone

2. WWTP - wastewater treatment plant

3. TDS - total dissolved solids
Nationa
Forest
cho
:amonga Highland
rona
0Riverside
Perris
an Gorgonio
ass
Study Area and
Water Quality Objectives Map
City of Beaumont AMMP
Figure 2-1

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

2.2 Regulatory Setting
The following subsections describe the regulatory and monitoring programs related to operation of the Beaumont WWTP to which the City adheres.

2.2.1 Regional Water Quality Control Board Requirements The City of Beaumont is within the jurisdictional region of the Santa Ana Regional Water Quality Control Board (Santa Ana Water Board), the regulatory agency responsible for the protection of water quality in the Santa Ana Region. The Santa Ana Water Board regulates waste discharges to minimize and control the impacts on the quality of the region's groundwater and surface water resources. Discharge from the Beaumont WWTP is regulated by the Santa Ana Water Board in accordance with Order No. R8-2022-0042 (National Pollutant Discharge Elimination System [NPDES] No. CA0105376) (Santa Ana Water Board, 2022).

The Santa Ana Water Board has a Water Quality Control Plan for the Santa Ana River Basin (Basin Plan).

The Basin Plan defines groundwater management zones (GMZ) and surface water bodies and the associated beneficial uses and water quality objectives that must be considered by the Regional Board in permitting waste discharges. The Basin Plan contains a detailed regional salt and nutrient management plan (SNMP) that supports the process to establish discharge limitations for total dissolved solids (TDS) and nitrate as nitrogen (nitrate -nitrogen) that are protective of the receiving water bodies. In some cases, the Basin Plan SNMP contains GMZ-specific SNMPs known as maximum -benefit SNMPs. These GMZ-specific SNMPs allow for less -stringent TDS and nitrate -nitrogen groundwater objectives to enable local agencies to maximize recycled water reuse for the benefit of water resources management. Access to the less -stringent maximum -benefit based water quality objectives requires the sponsoring agencies to implement a program of projects and management actions, known as Maximum Benefit commitments, to ensure the long-term protection of beneficial uses of the affected GMZs.

Cooper's Creek and San Timoteo Creek overly the Beaumont and San Timoteo GMZs, both of which have Maximum Benefit SNMPs defined in the Basin Plan. The boundaries of the Beaumont and San Timoteo GMZs, and their associated TDS and nitrate -nitrogen objectives, are shown on Figure 2-1 and summarized in Table 2-1.

WEST YOST
6

Page 2113 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
Table 2-1. Summary of Water Quality Objectives
Program
Constituent
Water Quality Objective, mg/L
NPDES Permit Effluent Limitations
DP001la1
TDS
400
300
TIN
6 3.6
Beaumont Groundwater Management Zone
Maximum Benefit
TDS
330
Nitrate -nitrogen
TDS
5 Antidegradation
230
Nitrate -nitrogen

1.5 San Timoteo Groundwater Management Zone
Maximum Benefit
TDS
400
Nitrate -nitrogen
TDS
5 Antidegradation
300
Nitrate -nitrogen

2.7 (a) DP001 - Beaumont Wastewater Treatment Plant discharge point 001. 'Top' objectives are effluent limitations for discharges up to 1.8 mgd and 'bottom' objectives are effluent limitations for discharges above 1.8 mgd. mg/L = milligrams per liter
NPDES = National Pollutant Discharge Elimination System TDS = total dissolved solids
TIN = total inorganic nitrogen
The City is a joint responsible agency along with the YVWD, Beaumont Cherry Valley Water District (BCVWD), City of Banning, and San Gorgonio Pass Water Agency for the Beaumont GMZ Maximum Benefit SNMP. For the San Timoteo Maximum Benefit SNMP, the City is a joint responsible agency with the YVWD.

In 2014, the Maximum Benefit SNMPs for the Beaumont and San Timoteo GMZs were updated (Basin Plan Amendment R8-2014-0005) to revise the maximum benefit commitments for the responsible agencies.

Under the amended Maximum Benefit SNMPs, the YVWD and the City were required to produce a non -potable (recycled water) supply with 10 -year, volume -weighted running average TDS and nitrate -nitrogen concentrations that are less than or equal to the maximum benefit objectives shown in Table 2-1 for the underlying GMZs. The amended Maximum Benefit SNMP also triggered updates to the discharge permits for the City and YVWD discharges to the Beaumont and San Timoteo GMZs. In 2015, the discharge permit for the Beaumont WWTP was updated (R8-2015-0026, Santa Ana Water Board, 2015) and required the City to further limit the TDS and total inorganic nitrogen (TIN) concentrations to 300 mg/L and 3.6 mg/L, respectively, for discharges in excess of 1.8 mgd. The lower concentration requirements were based on the antidegradation objectives for the San Timoteo GMZ that existed prior to the adoption of the Maximum Benefit SNMP.

WEST YOST
7

Page 2114 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
The most current NPDES permit for City's discharge, Order R8-2022-0042, was adopted by the Santa Ana Water Board in October 2022. Order R8-2022-0042 maintained the same TDS and TIN limits that include the lower concentration limit for discharges over 1.8 mgd:
• For discharges up to 1.8 mgd, the 12 -month flow -weighted running average shall not exceed 400 mg/L for TDS and 6 mg/L TIN.
• For discharges exceeding 1.8 mgd, the 12 -month flow -weighted running average shall not exceed 300 mg/L for TDS and 3.6 mg/L for TIN.

At the time of the adoption of the 2015 discharge permit (R8-2015-0026), the City's treated discharge was not in compliance with these effluent limitations for TDS and TIN. For this reason, the Santa Ana Water Board requires the City to account for and eventually "offset" the amount of TDS and nitrate loading that exceeds the limits specified in R8-2015-0026 and R8-2022-0042. The offset will be achieved by operating the RO system that was completed in 2020 to produce effluent with TDS and TIN concentrations that are lower than the permit limits for a period of time until the long-term average concentrations meets the required targets. The Santa Ana Water Board set a date of January 1, 2027 to fully offset the excess TDS and nitrate loading that occurred from 2015 until the RO system was completed (Santa Ana Water Board, 2022). To meet the obligation, the City has a goal to discharge effluent at a TDS concentration of 200 mg/L or less through 2027.

2.2.2 State Water Resource Control Board Requirements
Now that the City's upgraded WWTP is fully operational and the offset process is underway, the City would like to develop a plan to utilize the highly -treated effluent supply to enhance is local water supply plan through reuse and/or groundwater recharge. The SWRCB Division of Water Rights regulates the diversion of surface waters within the State of California. For the City to reduce their discharge to Cooper's Creek and begin utilizing the recycled water for non -potable uses, they are required to file a Change Petition under California Water Code Section 1211. Upon notification from the City of its goal to move forward with plans to reduce the WWTP discharge to Cooper's Creek , the SWRCB directed them to complete a Change Petition, including initiating the process to develop an AMMP.

The recycled water will likely be used as a non -potable supply for City customers, and potentially other future projects such as groundwater recharge. However, at the time of drafting this report, no final decisions have been made on end use of the recycled water. Non -potable supply system infrastructure is in place and is owned by the BCVWD and is ready to receive recycled water supply. The primary limitation to moving forward with the non -potable supply deliveries is obtaining approval of the Change Petition from the Division of Water Rights. The development of the AMMP is a critical step in the approval of the Change Petition.

2.2.3 Existing Monitoring and Reporting Programs
Several programs requiring monitoring and/or reporting of environmental data are active within the Study Area:

1. Groundwater level and quality, and surface water flow and quality data are collected in compliance with the Maximum Benefit Monitoring Program for the Beaumont and San Timoteo GMZs.

2. Beaumont WWTP effluent water quality and discharge data are collected pursuant to the Monitoring and Reporting Program under R8-2022-0042.

WEST YOST
8

Page 2115 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

3. Biological surveys are performed by the Santa Ana Watershed Association (SAWA) along the San Timoteo Creek.

2.2.3.1 Maximum Benefit Monitoring Program
The Maximum Benefit Monitoring Program is implemented in accordance with the Basin Plan. In both the Beaumont and San Timoteo GMZs, there are maximum benefit commitments which include conducting groundwater and surface water monitoring. The Maximum Benefit monitoring activities and data collected are described in Annual Reports that are submitted to the Santa Ana Water Board by April 15th each year by the responsible agencies (Dudek, 2021). The surface water and groundwater monitoring programs within the Beaumont and San Timoteo GMZ Maximum Benefit Monitoring Programs are summarized as follows and a subset of the monitoring locations are shown on Figure 2-2:
• Surface Water Monitoring Program. Surface water flow measurements and water quality grab samples are collected at 13 sites at a biweekly frequency, or for certain sites, following storms.
• Groundwater Monitoring Program. Groundwater levels are collected at 135 wells at least twice per year, and water quality samples are collected at 84 wells at least once every three years.

The last published Maximum Benefit Monitoring Program report relied on for this Report is from 2022.

2.2.3.2 Beaumont WWTP NPDES Permit Monitoring
As part of their NPDES Permit reporting, the City monitors the volume and water quality of discharges from DP001 to Cooper's Creek. The data is reported to through the California Integrated Water Quality System Project (CIWQS).

2.2.3.3 SAWA Biological Monitoring
SAWA performs biological monitoring activities within the San Timoteo Canyon area and produces monitoring reports on an annual basis. The last published report relied on for this Report is from 2022.

2.2.4 Water Rights
Groundwater beneath portions of the City is within the adjudicated Beaumont Basin, to the north and east of the Study Area (see Figure 2-1). Pursuant to a Judgment issued in 2004, the Superior Court of the County of Riverside appointed a five -member Watermaster committee, the Beaumont Basin Watermaster, consisting of representatives from the City of Banning, BCVWD, the City, South Mesa Water Company (SMWD), and YVWD (ALDA Inc. and Thomas Harder & Co, 2024). The Judgment regulates the amount of water that can be pumped from the Basin and defines monitoring and management actions to ensure that pumpers in the Basin can utilize groundwater in accordance with their rights.

WEST YOST
9

Page 2116 of 2775 ends

City of Beaumont
May 2025

YV W D -At
#428, Agri -Empire #2
Prepared by:
41/

WEST I YOST
#427, Agri -Empire
�--SanJim_2B/1
San Tim -2B/2..)
Heartland
Well
San Timoteo Creek "\
CC -03
OBMW-2 '.. OBMW-1
6,000
Scale in Feet
Ranch,Well
12,000

Page 2117 of 2775 ends

Prepared for:

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMPJ BEAUMONT
— — Streams
rrC
♦
♦
Beaumont WWTP Boundary
San Timoteo GMZ
Riparian Zone
Study Area
GW wells with WL and WQ data
GW wells with WL data
GW wells with WQ data
O Stream Gage
• WWTP Discharge Point
Geology
Water -Bearing Sediments
Unconsolidated to Semi -consolidated Quaternary
Alluvium
Consolidated and Semi -Consolidated Formations
San Timoteo Formation
NIUndifferentiated Pre -Tertiary Igneous and
Metamorphic Crystalline Rocks
Notes:

1. Riparian Zone was drawn using tree line.

2. GW - groundwater; SW - surface water

3. GMZ - groundwater management zone

4. WWTP - wastewater treatment plant

5. WL - water level; WQ - water quality
Nationa
Forest
cho
:amonga Highland
-ona
ORiversid€
Redlands
Perris
ucat
��[ 5
an Gorgonio
ass
Hydrogeological Monitoring Locations -
Beaumont and Upper San Timoteo GMZs
City of Beaumont AMMP
Figure 2-2

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

2.3 Physical Setting
This subsection describes the surface water hydrology, geologic setting, and hydrogeologic setting for the Study Area and its vicinity.

2.3.1 Surface Water Hydrology
The following subsections describe the surface water bodies and climate of the Study Area region.

2.3.1.1 Surface Water Bodies
Figure 2-3 shows the boundary of the San Timoteo Watershed (Watershed), within which the Study Area is located. The Watershed (also known as the San Timoteo Wash Watershed) drains an approximately 125 -square mile area. The Watershed receives most of its water from the San Bernardino Mountains near Cherry Valley to the north, where many of the tributary headwaters are located. The eastern -most extent of the Watershed is located at a topographic high between the Cities of Beaumont and Banning. San Timoteo Creek is the main drainage of the Watershed, which flows northwest to its confluence with the Santa Ana River in San Bernardino, California.

Several smaller creeks are tributary to San Timoteo Creek. Noble Creek flows southwest from its headwaters in the San Bernardino Mountain Range to its confluence with San Timoteo Creek in the western portion of the City's limits. Cooper's Creek flows northwest to its confluence with San Timoteo Creek near the western boundary of the City's limits. Yucaipa and Oak Glen Creek are the main drainages of the Yucaipa Valley. The headwaters of these creeks are located in the San Bernardino Mountains and they flow to the west and southwest through the Yucaipa Valley. The confluence of the Oak Glen and Yucaipa Creeks is just south of Interstate 10 and prior to the Live Oak Canyon. The confluence of Yucaipa Creek with the San Timoteo Creek is outside of the Study Area, just downstream of the Henry N. Wochholz DP001. Noble, San Timoteo, and Cooper's Creeks are the main drainages of the Beaumont GMZ, and San Timoteo is the main drainage of San Timoteo GMZ.

Historically, the streams in this region exhibited intermittent flow. WWTP discharges from the City and YVWD have altered the natural hydrology and streamflow is now apparent year-round. Streams that do not receive discharges are observed to be flashier in nature and more intermittent flows are apparent in the geomorphology and through observations from the Maximum Benefit Monitoring Program.

More details on surface water hydrology, including water quality, flows, and other characteristics are discussed in Section 6.2 of this Report.

2.3.1.2 Climate and Precipitation
Climatically, the region is classified as hot -summer Mediterranean. Precipitation was analyzed within the Watershed for the period of record from WY 1986 to 2023. Average annual precipitation estimates were computed as a spatial average across the Watershed using rasterized data from the PRISM Climatic Group (based on an 800 -meter by 800 -meter grid). The long-term average annual precipitation in the Watershed is 19.3 inches per year (in/yr). Figure 2-4 is a time -history chart of the annual precipitation and cumulative departure from mean (CDFM) precipitation curve. The CDFM characterizes the occurrence and magnitude of wet and dry periods: positive sloping segments (trending upward to the right) indicate wet periods, and negative sloping segments (trending downward to the right) indicate dry periods. Thirty-three of the last forty years are considered 'dry' (1983 to 2023). The current dry period has extended from 1998 to 2023.

WEST YOST 11

Page 2118 of 2775 ends

City of Beaumont
May 2025

Prepared by:

Prepared for:
41/

WEST I YOST
.. yycaif r -mot-' 'ga , ' _
4-----' , _ nning Fault _
\- V ~.ice
Henry N not ./ ' �__ ` i / , -'- f:

Wochholz ff. i
RWRFDP001
_ 1 i
—, _ _
r j .r _
a ; iT�-� . -. 1 \_I-1)"---
I \ i.,!
i i
s
�\ it iSAN TIMOTEO ��"� -••� • i �•�
1 �' BADLANDS .

Beaumont �•- !
I WWTP DP001 i ...i
\ L= i i\ \\ \ I.

N V, \

Page 2119 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMPJ BEAUMON1
— - Streams
I._ City of Beaumont
n Study Area
Beaumont WWTP Boundary
Adjudicated Basin Boundary
San Timoteo GMZ
n Beaumont GMZ
San Timoteo Watershed Boundary
I— Upper Santa Ana Valley San Timoteo Subbasin
• WWTP Discharge Point (active)
Geology
Water -Bearing Sediments
Unconsolidated to Semi -consolidated Quaternary
Alluvium
Consolidated and Semi -Consolidated Formations
r San Timoteo Formation
-Undifferentiated Pre -Tertiary Igneous and
Metamorphic Crystalline Rocks
Faults
— fault, approx. located
fault, certain
fault, concealed
Fault Zones
San Gorgonio Pass Fault Zone
Beaumont Plain Fault Zone
San Jacinto Fault Zone
Notes:

1. GMZ - groundwater management zone

2. WWTP - wastewater treatment plant

3. The upper portion of the San Timoteo Formation is considered to be the lower/confined aquifer and generally and unconformably underlies the Quaternary -aged Alluvium. The San Timoteo Formation outcrops on the northern side of the San Timoteo Canyon.

Hydrologic and Hydrogeologic Features
of the San Timoteo Watershed
City of Beaumont AMMP
Figure 2-3

50 45
40 35
• 30
t
o 25
f
•is
U
a 20
C
< 15
10 5
0 Annual Precipitation for San Timoteo Wash - PRISM Spatial Average Across the San Timoteo Wash Watershed — Average Annual Precipitation for Water Years 1895-2023 (19.3 inches) from
Cumulative Departure the Mean Precipitation (CDFM)
1V
I
Dry Wet Dry Wet Dry Wet Dry Wet Dry
4 ►/ IN H H H IN H 4 ►
1904 1922 1934 1945 1977 1983 1991 1998 2023
cb
wi

WEST I YOST
Water. Engineered.
l l
O yh LO ti� ,�O 'bh CO Rh h0 �� OO co� �° 1� �O W� OO �� OO O� N. y� ti0
Author: AK
Date: 20250102
File: Figure 2-4—Beaumont_CDFM.grf
100
- 90
- 80
70 60
50 40
30 20
10 0
- 10
- 20
- 30
- 40
Cumulative Departure from the Mean Precipitation (inches) Annual Precipitation in the
San Timoteo Watershed
Water Year 1895 - 2023

Page 2120 of 2775 ends

Figure 2-4

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

2.3.2 Geologic Setting
Figure 2-3 shows the geology of the Study Area and its surroundings. The Study Area is located within the Peninsular Range geomorphic province and sits in a low -relief highland (or plateau) between the San Bernardino Mountain Range to the north and the San Jacinto Mountain Range and San Timoteo Badlands to the south and southeast. Bedrock outcrops to the south of the City and within the San Jacinto Mountains are dominantly Mesozoic -aged plutonic rocks (various granitoid compositions) and older Paleozoic to Mesozoic -aged metasedimentary rocks (shown in dark green on Figure 2-3). The San Bernardino Mountains are comprised of mostly of plutonic granitoid rocks of Pre -Cambrian to Mesozoic ages and are heavily fractured and weathered (Fraser, 1931; Rewis et al., 2006). The San Timoteo Badlands are generally made up of terrestrial sedimentary bedrock of the Pliocene and Pleistocene aged San Timoteo Formation (shown in tan on Figure 2-3), with instances of sandstone, claystone, and conglomerate (Fraser, 1931).

2.3.2.1 Local Geologic Setting
Much of the City and Study Area overlies Quaternary -aged alluvial surficial deposits (shown in gray on Figure 2-3) that are Holocene to Pleistocene in age comprised of unconsolidated to semi -consolidated gravels, sands, silts, and clays (Rewis et. al., 2006). The plateau (commonly referred to as the Yucaipa -Beaumont Plain), slopes generally to the south and west draining from the San Bernardino Mountains and San Gorgonio Pass area and has been incised by the San Timoteo Creek and its tributaries.

The San Timoteo Formation generally underlies the alluvial deposits above and a topographic "high" or divide is located between the Cities of Banning and Beaumont where a bedrock high within the San Timoteo Formation occurs (shown as the watershed divide on Figure 2-3). The incised portion of the San Timoteo Canyon overlies Quaternary -aged alluvial surficial deposits, while the hillslopes are predominantly San Timoteo Formation (Rewis et al., 2006).

2.3.2.2 Geologic Structure
Structurally, the Study Area is located within the San Andreas Fault Zone. The modern trace of the San Andreas Fault lies to the north. Several other fault zones are located in the area and help relieve stresses applied by the San Andreas Fault Zone — the Banning Fault and the San Gorgonio Pass Fault Zone to the north, the Beaumont Plain Fault Zone to the southeast, and the San Jacinto Fault Zone to the southwest (Rewis et al., 2006). General trends of these fault zones are to the northwest and southeast. A major anticlinal fold structure is present within the San Timoteo Formation and San Timoteo Badlands that plunges to the northwest.

2.3.3 Hydrogeologic Setting
Figure 2-3 shows the hydrogeologic setting of the Study Area and its surroundings. As previously described, the Study Area is located within the San Timoteo Watershed and the Upper Santa Ana Valley San Timoteo Subbasin. The Study Area partially overlies the western portion of the adjudicated Beaumont Basin and portions of the Beaumont and San Timoteo GMZs. The southeastern portion of the Study Area is located within the Beaumont GMZ and the northwestern portion of the Study Area is within the San Timoteo GMZ. The Beaumont GMZ is generally within the Quaternary -aged alluvial sediments and is bordered by the Banning Fault to the north. The San Timoteo GMZ borders the southern boundary of the watershed and extends downstream toward the Santa Ana River. The northern extent of the San Timoteo GMZ is generally bordered by the Banning Fault to the north and the GMZ consists of Quaternary -aged alluvial sediments and the San Timoteo Formation.

WEST YOST 14

Page 2121 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

2.3.3.1 Water Bearing Formations
The local water -bearing formations generally consist of two formations: the older and upper portion of the Pliocene and Pleistocene San Timoteo Formation and the overlying younger Quaternary -aged alluvium. The alluvium is defined as the upper aquifer and the regional unconfined water table, while the San Timoteo Formation is defined as the lower aquifer and is confined (Dutcher and Garrett, 1963., Rewis et al., 2006). Thicknesses of these aquifers range from 400 to 800 feet (ft) (upper) and up to 400 ft (lower), respectively. The lower aquifer is observed to be more cemented and contains higher percentages of silts and clays. Transmissivity values average approximately 6,000 square feet per day (ft2/day) in the upper aquifer and 2,000 ft2/day in the lower aquifer. The upper aquifer generally contributes more than 75 percent of groundwater produced from wells in the area (Rewis et al., 2006).

2.3.3.2 Groundwater Occurrence and Flow
Groundwater recharge replenishes the aquifer system via infiltration within unlined streams (e.g., Cooper's and San Timoteo Creeks), regional recharge basins, underflow from adjacent groundwater subbasins, mountain -front recharge, and deep percolation from precipitation. Groundwater discharge occurs from groundwater production, underflow to the west through the San Timoteo Canyon, and rising groundwater to the San Timoteo Creek and as springs within San Timoteo Canyon and Creek.

Groundwater occurs under confined and unconfined conditions with the Study Area depending on location and depth (WEI, 2005).

Groundwater flow and gradient within the Study Area and adjudicated Beaumont Basin is variable and likely controlled by faulting and location (ALDA Inc. and Thomas Harder & Co, 2024). General observations for groundwater flow direction and gradient for the region are outlined below:
• Northward in the west central portion of the adjudicated Beaumont Basin (west of Beaumont Plains Fault Zone)
• West near Calimesa and toward the San Timoteo Creek
• West-northwest adjacent to the San Timoteo Badlands and through the San Timoteo Creek Groundwater flow beneath the Study Area is to the northwest from the Beaumont Basin through the San Timoteo Canyon to the San Bernardino Valley. The numerous faults in the vicinity of the City and Study Area act as flow barriers, which are apparent in the difference in groundwater elevation across fault traces, up to 100s of feet in some areas.

Groundwater depths below the ground surface vary throughout the Study Area, with shallower depths observed near Cooper's and San Timoteo Creeks and are deeper away from the Creeks. Based on 2022 groundwater elevations, depths to groundwater also fluctuate along the channel with shallower depths observed near the Beaumont and YVWD discharge points.

2.3.3.3 Groundwater Age and Quality
Produced groundwater within the upper aquifer is less than 50 years old, while the age of groundwater produced from the lower aquifer is much older (USGS, 2006).

WEST YOST 15

Page 2122 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
Generally, groundwater is of good quality. A primary focus of monitoring through the Maximum Benefit Program is TDS and nitrate -nitrogen concentrations. The program requires sampling at selected wells at a minimum once every three years in the area. Sources of TDS and nitrate -nitrogen in the region and the Study Area are from:
• Beaumont WWTP DP001 and YVWD Henry N. Wochholz WWTP DP001 • Imported water
• Recycled water use
• Stormwater runoff
Water quality indicators vary generally with depth and location. A 2006 United States Geological Survey (USGS) study in the region indicated TDS concentrations ranging from 177 mg/L to 823 mg/L, nitrate -nitrogen concentrations ranging from 1.0 mg/L to 11.3 mg/L, and fluoride concentrations ranging from 0.5 mg/L to 3.0 mg/L. The groundwater is generally characterized as calcium/magnesium- bicarbonate type water or sodium -bicarbonate type water (Rewis et al., 2006). Between 2020 and 2022, TDS concentrations ranged from 230 mg/L to 840 mg/L and nitrate -nitrogen concentrations ranged from non -detect to 16 mg/L in the San Timoteo GMZ (Dudek, 2022). Over this same time period, TDS concentrations ranged from 170 mg/L to 870 mg/L and nitrate -nitrogen concentrations ranged from

0.98 mg/L to 18 mg/L in the Beaumont GMZ.

Groundwater quality for the Study Area is discussed further in Section 6.4.

WEST YOST 16

Page 2123 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

3.0 INITIAL GOALS, OBJECTIVE, AND PERFORMANCE CRITERIA
The following subsections describe the initial goals, objectives, and performance criteria the City would like to see during the drafting and implementation of the AMMP. A draft technical memorandum of initial goals, objectives, and performance criteria was delivered to the City in December 2023 and is included as Appendix A.

3.1 Goals and Objectives
The City's goals for the AMMP are as follows:

1. Obtain approval for the lowest feasible discharge volume to enable the City to maximize the amount of recycled water that can be used for planned non -potable supply projects in the City service area, as well as for potential future projects for non -potable supply or recharge in the Beaumont groundwater basin.

2. Appropriately characterize the various climate, hydrogeologic, and other factors that have contributed to the extent and health of the riparian habitat that may also have historically benefited from the City's discharges.

3. Avoid unmitigable degradation to riparian habitat that could result through development of a robust monitoring and mitigation plan to address degradation to riparian habitat health due to decreased discharge from DP001.

4. Utilize existing monitoring programs and analytical tools to the extent practical to avoid duplicative work and achieve cost efficiency.

5. Establish a dialogue with other dischargers in the area to promote collaboration, openness, sharing of ideas and actions, and to promote the success of the project with stakeholders and/or other dischargers. The other discharge in the region is the YVWD.

6. Establish a dialogue with the SWRCB Division of Water Rights to ensure the development of an AMMP that meets expectations and a process to gain approval of the Change Petition.

Given its many investments in the Beaumont WWTP upgrades and non -potable supply system infrastructure, goal number one is the primary goal for the City. While there is an important goal for cost efficiency and avoiding duplicative work efforts, designing an AMMP to meet the primary goal may require more robust modeling efforts in future phases of work to assess the long-term effects of reduced discharges as it pertains to riparian health, and to best assess effectiveness of potential mitigation actions.

Goal number five for open communication with other local stakeholders and regulators will also be critical to achieving goal number one. A key local stakeholder is the YVWD due to their downstream discharges on San Timoteo Creek and co -responsible agency with the Maximum Benefit SNMP. Any changes to the City's discharge could impact how the YVWD manages its discharge and any requirements to manage riparian habitat.

The City plans to accomplish these goals through the development and implementation of the AMMP.

The objectives in support of the City's goals for Phase 1 of the AMMP are as follows:

1. Quantify the extent and health of the riparian habitat in the immediate vicinity of DP001 and downstream areas that may benefit from the City's discharges

2. Quantify the climate and hydrogeologic factors that have contributed to the extent and health of the riparian habitat.

WEST YOST 17

Page 2124 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

3. Characterize the range of hydrogeologic conditions that contribute to healthy riparian habitat.

4. Define the extent of riparian habitat that benefit from discharges from the City's WWTP on Cooper's Creek and identify the potential impacts to riparian habitat and hydrogeologic conditions from reduced discharges.

5. Define data gaps and uncertainties that exist in defining the baseline condition of the riparian and hydrogeologic conditions (e.g. current conditions based on current discharge rates at DP001).

6. Define a monitoring program necessary to fill the data gaps and uncertainties in the baseline conditions.

7. Define the analytical tools needed to assess impacts to the hydrogeologic system at various levels of reduced discharge.

8. Establish a process for external communication with stakeholders.

3.2 Performance Criteria
Performance criteria are defined as a specific set of measurable standards used to evaluate the success of the AMMP. Performance criteria should be based on the baseline riparian habitat and hydrologic characterizations described in this Report. The preliminary performance criteria are as follows and are discussed in further detail in Section 9 of this Report:

1. Riparian habitat will not be adversely affected by reduction in discharges.

2. Minimum discharges will be maintained to levels determined necessary to sustain habitat along the Study Area that have historically benefited from WWTP discharges.

3. The water table depth in the Riparian Zone should be monitored to ensure that reductions in surface water flows do not result in a drop in groundwater levels that will negatively impact riparian health.

WEST YOST 18

Page 2125 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

4.0 HISTORICAL AND EXISTING BIOLOGICAL RESOURCES
This section characterizes historical and existing biological resources within the Study Area.

4.1 Regional Ecological Setting
For the purpose of the AMMP, historical and existing biological resources were evaluated in the Riparian Zone of the Study Area outlines on Figure 2-2. The Riparian Zone consists of the Cooper's Creek riparian corridor from the Beaumont WWTP DP001 outfall to the confluence with San Timoteo Creek and the riparian corridor along San Timoteo Creek to at the end of the Study Area boundary at Henry N. Wochholz RWRF DP001.

The Study Area is situated in the geographically based ecological classification known as the Inland Valleys — Level IV Ecoregion of the Southern California/Northern Baja Coast — Level II I Ecoregion. Level IV Ecoregions are subregions within the larger Level III Ecoregions. The goal of regional ecological classifications is to reduce variability based on spatial covariance in climate, geology, topography, climax vegetation, hydrology, and soils. The Southern California/Northern Baja Coast (Ecoregion 85) includes coastal and alluvial plains, marine terraces, and some low hills in the coastal area of Southern California (Griffith et al., 2016). The Inland Valleys Ecoregion (Ecoregion 85k), which is a subregion of Ecoregion 85, consists of alluvial fans and basin floors immediately south of the San Gabriel and San Bernardino Mountains of Ecoregion 8, as well as the San Jacinto and Perris Valleys toward the south. Ecoregion 85k includes some floodplains along the Santa Ana River, including San Timoteo Creek. Vegetation historically included Riversidean coastal sage scrub, valley grasslands, and some riparian woodlands (Griffith et al., 2016). This Ecoregion also has less marine influence on climate than other valley regions to the west, such as the Los Angeles Plain.

4.1.1 Regional Riparian Ecology
The riparian zones along streams and rivers in the arid and semi -arid regions in the western United States are typically narrow and linear, with steep gradients and narrow floodplains (Mitsch and Gosselink 2015).

These narrow riparian zones contrast starkly with the surrounding upland habitats. The complexity of the riparian plant community structure and species composition depends on the influence of the local flood regime, sediment deposition, movement of the stream channel over time, and the hydroperiod (Griggs, 2009). Mature riparian habitats of the Inland Valleys Ecoregion are typically dominated by winter deciduous trees and have a maximum canopy height of 30 meters, with a canopy cover ranging from 20 to 80 percent (Grenfell, n.d.). A subcanopy tree layer and understory of shrubs and woody vines such as blackberry (Rubus spp.3), shrubby willows (Salix spp.), elderberry (Sambucus mexicana), poison oak (Toxicodendron diversilobum), and wild grape (Vitis spp.) is present. Very little herbaceous cover typically exists (around 1 percent cover) in these mature riparian habitats, with 30 to 50 percent of the ground cover coming from woody vine species like wild grape (Grenfell, n.d.). Herbaceous species that are present might include sedges (Cyperaceae), rushes (Juncaceae), grasses (Poaceae), and/or nettles (Urticaceae).

Riparian plant communities in the regional vicinity of the Study Area Riparian Zone are commonly dominated by Fremont cottonwood (Populus fremontii), California sycamore (Platanus racemosa), willows, mulefat (Baccharis salicifolia), and other phreatophytes adapted to a high water table along streams and rivers. These species require root access to the capillary fringe above the water table at all 3 Spp. = species
WEST YOST 19

Page 2126 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
stages of life and typically have a root system that extends down to around 5 meters or less (Kibler et al., 2021). Depending on soil texture, the vertical extent of the capillary fringe can range from 1.5 centimeters in gravelly soils, to 100 centimeters in very fine sands, to 750 centimeters in fine silty soils (Fetter, 1994).

Due to requiring a relatively shallow depth to groundwater, phreatophytes are particularly vulnerable to water table declines (Williams et al., 2022). Maximum recorded rooting depths for Fremont cottonwood range from 0.8 meter to 2.1 meters (Zimmerman, 1969; Shafroth, Stromberg, and Patten, 2000; Rood, Bigelow, and Hall, 2011). Gooding's willow (Salix gooddingii) and red willow (Salix laevigata) have maximum recorded rooting depths of 2.1 meters and 1 meter, respectively (Stromberg, 2013; Stover et al., 2018). The maximum recorded rooting depth for mulefat is 0.6 meters (Gary, 1963; Stromberg, 2013).

Phreatophytes such as Fremont cottonwood and Gooding's willow are sensitive to drought conditions and the effects of water stress on cottonwood and willow species resulting from increased depth to groundwater can include the production of smaller leaves and reduced stomatal conductance, reduced shoot growth, leaf and branch shedding, canopy dieback, cavitation, and death. Dense, structurally diverse forests of these species typically only occur along intermittent or perennial streams, where the depth to groundwater is less than 4 meters (Lite and Stromberg, 2005). Although Fremont cottonwood can grow in areas that only have high water tables seasonally, this tends to result in sparse stands with low age class diversity. Gooding's willow and other similar Salix species require a permanently shallow saturation zone (Lite and Stromberg, 2005).

The seasonal growth, reproductive timing, and seedling establishment of riparian plant communities are determined by the regional climate and local hydroperiod. Fremont cottonwood and willow dominated riparian habitats such as those present in the Riparian Zone typically have an active growth period that extends from February through the end of September. Leaf abscission typically occurs in October/November, and a dormant period typically extends from October/November to February/March, depending on species and annual fluctuations in weather patterns (Griggs, 2009). Seed dispersal typically begins in late April to early May and may continue into July and August. Winter peak stream flows redistribute sediment and scour floodplain surfaces, creating exposed point bars comprised of moist sand and fine sediments that wind-blown seeds can land and germinate on. Seedlings develop rapidly growing taproots that follow the receding water table through the growing season, resulting in the establishment of 1.5- to 2 -meter -tall saplings by the end of their first growing season (Griggs, 2009).

Riparian plant community descriptions were obtained for the Riparian Zone by a combination of field surveys conducted by HDR biologists in August of 2024 and existing plant community descriptions provided in the CNPS online edition (2024) of the "Manual of California Vegetation" for the plant communities identified in the Riparian Zone by the WRC-RCA's 2012 updated vegetation maps (AIS 2015).

According to the results of the field surveys and the Manual of California Vegetation plant community descriptions for habitats mapped in the Riparian Zone, the dominant native riparian species present within the Riparian Zone are willows (multiple species), Fremont cottonwood, and mulefat. These species propagate via wind -dispersed seed and vegetative means including root and shoot sprouting. Seed germination and seedling establishment occurs when seed is carried by the wind or water and is deposited on exposed moist substrates such as flood deposited sandbars. Vegetative propagation occurs when roots, stumps, or branches from the parent trees sprout new shoots. Given the dense, mature tree cover and narrow floodplain along the Cooper's Creek portion of the Study Area, it is likely that recruitment occurs primarily via vegetative propagation as there is very little opportunity for seed germination and seedling establishment within the riparian zone. However, the San Timoteo Creek portion of the Study WEST YOST 20

Page 2127 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
Area has a broader floodplain and appears to be subject to more natural fluvial processes that would be conducive to the conditions required for seed germination and seedling establishment.

Healthy riparian zones with surface water and complex vegetation structure support high biodiversity and large numbers of wildlife that require riparian habitats for their survival, including those species that utilize riparian zones as regional migration routes (Griggs, 2009). Avian fauna diversity is a particularly important indication of the health of a riparian habitat, and the California Partners in Flight and Riparian Habitat Joint Venture (RHJV) have selected 17 riparian associated indicator species or "focal species" representative of a range of healthy riparian systems (RHJV, 2004). These focal species were selected based on the following factors:
• Riparian vegetation is used as their primary breeding habitat in most bioregions of California.
• These species warrant special management status i.e., endangered, threatened, or species of special concern on either the federal or state level. • They have experienced population declines and a reduction in breeding range size from historical extent.
• They commonly breed throughout California's riparian areas, which allows for adequate sample sizes for statistical comparisons and therefore the ability to rapidly assess responses to changes in management.
• They have breeding requirements that represent the full range of successional stages of riparian ecosystems.

The 17 riparian -associated focal species selected by the California Partners in Flight and RHJV in their 2004 Riparian Bird Conservation Plan are:
• Swainson's Hawk (Buteo swainsoni)
• Spotted Sandpiper (Actitis macularius)
• Western Yellow -billed Cuckoo (Coccyzus americanus occidentalis) • Willow Flycatcher (Empidonax traillii)
• Warbling Vireo (Vireo gilvus)
• Least Bell's Vireo (Vireo bellii pusillus)
• Bank Swallow (Riparia riparia)
• Tree Swallow (Tachycineta bicolor)
• Swainson's Thrush (Catharus ustulatus)
• Yellow Warbler (Setophaga petechia)
• Common Yellowthroat (Geothlypis trichas)
• Wilson's Warbler (Cardellina pusilla)
• Yellow -breasted Chat (Icteria virens)
• Song Sparrow (Melospiza melodic)
• Black -headed Grosbeak (Pheucticus melanocephalus)
• Blue Grosbeak (Passerina caerulea)
• Tricolored Blackbird (Agelaius tricolor)
WEST YOST 21

Page 2128 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

4.2 Historical Biological Resources
Data regarding historical biological resources in the Study Area were obtained through literature review and desktop evaluation. Three main sources were reviewed and analyzed, including historical aerial imagery, the California Natural Diversity Database (CNDDB), and reports documenting wildlife occurrence along San Timoteo Creek.

Historical aerial imagery of the Study Area dating back to 1966 was reviewed to provide an understanding of the historical presence and development of riparian habitats along Cooper's Creek and San Timoteo Creek.

The most recent version of the CNDDB was searched for sensitive species data in the Beaumont, El Casco, and Sunnymead USGS 7.5 -Minute Series Quadrangles.4 This database contains records of reported occurrences of sensitive species and habitats that may occur in the vicinity of the Riparian Zone. This list of sensitive species and habitats tracked by CNDDB includes any state and/or federally listed —or proposed for listing —as threatened or endangered species, Candidate Species, California Fully Protected species, California Department of Fish and Wildlife (CDFW) designated Species of Special Concern (SSC), and otherwise "Special Animals." "Special Animals" is a general term that refers to all the taxa the CNDDB is interested in tracking, regardless of their legal or protection status. This list is also referred to as the list of "species at risk" or "special status species." The CDFW considers the taxa on this list to be those of greatest conservation need.

Historical data on wildlife usage of riparian habitat along San Timoteo Creek was also obtained from the Santa Ana Watershed Association (SAWA), through the Western Riverside County Regional Conservation Authority's (WRC-RCA's) Biological Monitoring Program annual reports from 2004 to 2022. These reports contain data collected by SAWA in support of the Western Riverside County Multiple Species Habitat Conservation Plan (WRC-MSHCP) annual monitoring and reporting requirements.

4.2.1 Cooper's Creek
The following subsections describe the historical plant communities and wildlife within the Riparian Zone along the Cooper's Creek portion of the Study Area.

4.2.1.1 Riparian Plant Communities
In its natural state, Cooper's Creek was an ephemeral stream that historically likely only supported sparse alluvial scrub plant communities adapted to infrequent flooding before the construction of the Beaumont WWTP and subsequent releases of treated wastewater. Prior to the early 1970s, the Riparian Zone along Cooper's Creek consisted of a narrow stand of riparian vegetation that extended less than 1 mile downstream (west) of the Beaumont WWTP DP001 outfall. By 1978, the Riparian Zone approximately doubled and extended downstream approximately to the crossing by California State Route 60 ([SR -60] approximately at the Beaumont and San Timoteo GMZs boundary ), and by 1985 the Riparian Zone appears to have extended all the way to the Cooper's Creek/San Timoteo Creek confluence. Based on the review of historical aerial imagery, it appears that the expansion of riparian habitats along Cooper's Creek can primarily be attributed to the increases in surface water flow due to increasing discharges of treated wastewater from the Beaumont WWTP. Historically, the developing Riparian Zone along Cooper's Creek would likely have consisted of early seral stage riparian plant 4 https://wildlife.ca.gov/Data/CNDDB
WEST YOST 22

Page 2129 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
communities dominated by shrubby willows, mulefat, and emergent Fremont cottonwood and California sycamore, with higher shrub and herbaceous cover than is currently present along the Cooper's Creek Riparian Zone.

4.2.1.2 Wildlife
Little historical data is available on the occurrence of riparian wildlife within Cooper's Creek. It is expected that wildlife use of habitat along Cooper's Creek would have increased with the growth of riparian habitat that resulted from historical increases in surface water flow associated with the release of treated wastewater from the Beaumont WWTP. With increased urban expansion resulting in habitat loss, degradation, and fragmentation in the surrounding area, the Riparian Zone along Cooper's Creek likely became an important local habitat linkage and wildlife movement corridor to more expansive downstream habitats within San Timoteo Canyon. The establishment of riparian habitat along Cooper's Creek to its confluence with San Timoteo Creek by the mid -1980s would also have provided increased dispersal opportunities for riparian species.

The Riparian Zone along Cooper's Creek provides foraging, breeding, and dispersal habitat for numerous wildlife species that occur in the region, particularly avian fauna. Cooper's Creek also provides temporary refugia for many migratory bird species. In addition to common riparian wildlife expected to occur in the vicinity of Cooper's Creek, several threatened, endangered, or otherwise rare special status species have been documented along this Riparian Zone, including the riparian associated focal species discussed below.

Least Bell's Vireo
The state and federally listed endangered Least Bell's vireo (LBVI) is a small migratory songbird that nests and forages almost exclusively in riparian habitats. LBVI nesting habitat typically consists of a well -developed overstory, understory, and low densities of aquatic and herbaceous cover. This species typically nests in the understory, which frequently consists of dense sub -shrub or shrub thickets. These thickets are often dominated by plants such as sandbar willow (Salix exigua), mulefat, young individuals of other willow species such as arroyo willow (Salix lasiolepis) or Gooding's willow, and one or more herbaceous species. LBVI generally begin to arrive from their wintering range in southern Baja California and establish breeding territories by mid -March to late -May.

According to the CNDDB, four breeding pairs of LBVI were observed within the riparian habitat along Cooper's Creek in 2013. Although these four breeding pairs are the only historically documented LBVI occurrences along Cooper's Creek, suitable LBVI habitat has been present along Cooper's Creek from the Beaumont WWTP DP001 outfall to the confluence with San Timoteo Creek since around the mid -1980s.

It is not known when exactly LBVI began occupying Cooper's Creek but based on the historical presence of suitable riparian habitat, it is likely that LBVI have used Cooper's Creek for breeding and/or migratory stopover habitat for at least the past several decades.

Willow Flycatcher
The willow flycatcher (WIFL) is a species of small passerine bird that consists of several recognized neotropical migrant subspecies. The southwestern willow flycatcher (Empidonax traillii extimus) is a subspecies of WIFL that breeds in the southwestern United States from mid -April to early -September. This subspecies is both state and federally listed as endangered. In the fall, it migrates south to its wintering grounds in portions of South America, Central America, and Mexico. WIFL typically nest in the understory of dense riparian habitats (at least 0.25 acres in size and at least 10 meters wide) along rivers, streams, and other wetlands at elevations ranging from sea level to 8,500 feet (Sogge, 2010). Plant species closely WEST YOST 23

Page 2130 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
associated with the WIFL include willows, boxelder (Acer negundo), and mulefat, with an overstory of Fremont cottonwood. Occupied habitat is generally dominated by shrubs and trees 4 to 7 meters or more in height, which provide dense lower and mid -story vegetation approximately 3 to 4 meters aboveground.

This dense vegetation is often interspersed with open water, small openings, or sparse vegetation, creating a mosaic that is not uniformly dense.

According to the CNDDB, WIFL were detected along Cooper's Creek in 2004 in habitat dominated by arroyo willow, Fremont cottonwood, and stinging nettle (Urtica dioica) with a tree canopy height of 11 meters. A second WIFL observation was made along Cooper's Creek the same year, approximately

0.5 mile downstream (west) of the first observation (CNDDB, 2024). The second 2004 WIFL observation was within habitat dominated by arroyo willow, Gooding's willow, and mulefat. Although these two WIFL observations are the only documented WIFL occurrences along Cooper's Creek, suitable WIFL habitat has been present along Cooper's Creek from the Beaumont WWTP DP001 outfall to the confluence with San Timoteo Creek since around the mid -1980s. It is not known when exactly WIFL began occupying Cooper's Creek or if the two historical observations were territorial birds or migrating individuals but based on the historical presence of suitable riparian habitat, it is likely that WIFL have used Cooper's Creek for breeding and/or migratory stopover habitat for at least the past several decades.

Yellow Warbler
The yellow warbler (YEWA) is a small, almost uniformly yellow, migratory songbird that typically nests in the midstory of deciduous riparian plant species, such as willows and cottonwoods, but also breeds locally in wild rose and more xeric plant species and habitats (RHJV, 2004). YEWA generally inhabit wet areas within early successional riparian communities, or in remnant or regenerating canopy species stands (RHJV, 2004). Early successional riparian communities form after a disturbance (e.g., flooding) and are characterized by high productivity and a prevalence of pioneer shrubs, emergent trees, and herbaceous species that are adapted to frequent flooding and high soil moisture. Cottonwoods (Populus spp.) and willows (Salixspp.) are common early successional riparian species (NRCS 2007). YEWA typically arrives in California in April and is mostly gone by October, breeding from mid -April into early August, with peak activity in June (Green 2005a). YEWA have been designated as a California SSC.

According to the CNDDB, YEWA have been observed within the riparian habitat along Cooper's Creek several times from 2007 to 2016. Suitable YEWA habitat has been present along Cooper's Creek from the Beaumont WWTP DP001 outfall to the confluence with San Timoteo Creek since around the mid -1980s.

It is not known when exactly YEWA began occupying Cooper's Creek but based on the historical presence of suitable riparian habitat, it is likely that YEWA have used Cooper's Creek for breeding and/or migratory stopover habitat for at least the past several decades.

Other Special Status Species
In addition to the riparian associated focal species discussed above, Cooper's hawk (Accipiter cooperii [COHA]) was observed nesting in riparian habitat dominated by arroyo willow, Gooding's willow, and mulefat along Cooper's Creek in 2004 (CNDDB, 2024). This species has been designated as a Watch List species by the CDFW, likely due to historical declines resulting from pesticide use and hunting. Suitable COHA breeding and hunting habitat has existed along Cooper's Creek for at least the past several decades.

WEST YOST 24

Page 2131 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

4.2.2 San Timoteo Creek
The following subsections describe the historical plant communities and wildlife within the Riparian Zone along San Timoteo Creek portion of the Study Area.

4.2.2.1 Riparian Plant Communities
Historically, San Timoteo Creek supported a mix of riparian and alluvial scrub plant communities between the Cooper's Creek and San Timoteo Creek confluence and the Henry N. Wochholz RWRF DP001. A mix of both early and later seral stages of riparian habitats have been present along San Timoteo Creek since at least the mid -1960s. By 1985, little to no alluvial scrub habitat existed within San Timoteo Creek between the Cooper's Creek/San Timoteo Creek confluence and the Henry N. Wochholz RWRF DP001. Riparian habitat present along San Timoteo Creek in 19805 was described as Southern Cottonwood Willow Riparian Forest (CNDDB, 2024). Holland (1986) described Southern Cottonwood Willow Riparian Forest habitat as "Tall, open, broad -leafed winter -deciduous riparian forests dominated by Populus fremontii, [Populus] trichocarpa, and several tree willows." Plant species characteristic of this riparian community are listed as California mugwort (Artemisia douglasiana), mulefat, Chilicothe (Marah macrocarpa), California sycamore, Fremont cottonwood, black cottonwood (Populus trichocarpa), Gooding's willow, sandbar willow, Pacific willow (Salix Iasiandra), arroyo willow, and stinging nettle.

4.2.2.2 Wildlife
The Riparian Zone along San Timoteo Creek has long provided foraging, breeding, and dispersal habitat for numerous wildlife species that occur in the region, particularly avian fauna. San Timoteo Creek provides temporary refugia for many migratory bird species, as well as overwintering habitat for several raptor species including merlin (Falco columbarius [MERL]) and white-tailed kit (Elanus leucurus [WTKI]) (WRC-MSHCP, 2010b, 2018a, and 2021a). This Riparian Zone is also an important habitat linkage for carnivorous mammals including bobcat, coyote, and long-tailed weasel (WRC-MSHCP, 2009a; 2010a; 2011; and 2012a). Like Cooper's Creek, it is expected that wildlife use of habitat along San Timoteo Creek is likely to have increased with the expansion of riparian habitat that resulted from increased surface water flow associated with increases in the discharge of treated wastewater from the Beaumont WWTP, as well as other sources from the surrounding area such as increased surface runoff from development.

With increased urban expansion resulting in habitat loss, degradation, and fragmentation in the surrounding area, the Riparian Zone along San Timoteo Creek will continue to be an important local habitat linkage and wildlife movement corridor.

In addition to common riparian wildlife expected to occur along San Timoteo Creek, several threatened, endangered, or otherwise rare special status species have been documented along this Riparian Zone, including the riparian associated focal species discussed below. San Timoteo Canyon is also a WRC-MSHCP "Core Area" for LBVI, WIFL, YEWA, yellow -breasted chat (YBCH), and COHA. The WRC-MSHCP defines Core Areas as, "[...] Habitat of appropriate size, configuration, and vegetation characteristics to generally support the life history requirements of one or more Covered Species." 5 The only relevant riparian plant community descriptions available for the San Timoteo Creek portion of the Study Area are from a 1980 CNDDB entry describing the habitat as "Southern Cottonwood Willow Riparian Forest." The SAWA biological monitoring reports for the WRC-RCA's Biological Monitoring Program that were included in the literature review pertain to wildlife usage of riparian habitat along San Timoteo Creek.

WEST YOST 25

Page 2132 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report
Least Bell's Vireo
According to the CNDDB, the earliest documented LBVI occurrence in San Timoteo Creek is from 1978.

More recently, SAWA biologists have observed LBVI nesting in riparian habitat along San Timoteo Creek in every year that they surveyed from 2006 to 2020 (WRC-MSHCP, 2007; 2008; 2009b; 2012b; 2015; 2018b; and 2021b). In 2017, SAWA documented 66 LBVI nests along San Timoteo Creek, 52 (79%) of which were successful, resulting in 164 fledglings (WRC-MSHCP, 2018b).

Willow Flycatcher
SAWA biologists observed a migrating WIFL along San Timoteo Creek in 2006 and a territorial WIFL (southwestern subspecies) in 2012 (WRC-MSHCP, 2007; and 2015). There are no other documented WIFL occurrences within San Timoteo Creek, despite there being seemingly suitable riparian habitat for this species present throughout this portion of the Study Area for possibly over 40 years.

Yellow Warbler
According to the CNDDB, there were 146 YEWA detections along San Timoteo Creek from 2007 to 2016.

SAWA biologists have observed YEWA nesting in riparian habitat along San Timoteo Creek in every year that they surveyed from 2006 to 2019 (WRC-MSHCP, 2007; 2008; 2009b; 2012b; 2015; and 2020).

Wilson's Warbler
The Wilson's warbler (Cardellina pusilla [WIWA]) is a small migratory songbird that is bright yellow colored with a black cap. This species typically nests in the understory of deciduous riparian plant species, such as willows, alders, and riparian shrubs, as well as in grass, nettles, and ferns (RHJV, 2004). WIWA nest within

0.3 to 3 meters off the ground and usually within 1 meter of the ground and prefer areas with tall trees and moderate to thick canopy cover (RHJV, 2004). This species is a seasonal migrant in southern California, with most spring migrants from Mexico and Central America passing through southern California in late April/early May, and most fall migrants returning through southern California in late August/early September (Green, 1990a). WIWA has no special legal status but is considered a riparian associated focal species by the California Partners in Flight and Riparian Habitat Joint Venture in their 2004 Riparian Bird Conservation Plan.

SAWA biologists observed four WIWA along San Timoteo Creek in 2007 (WRC-MSHCP, 2008). The Riparian Zone along San Timoteo Creek likely provides important migratory stopover habitat for this species.

Yellow -breasted Chat
The yellow -breasted chat (YBCH) is a medium sized migratory songbird that is olive-green dorsally, with a bright yellow breast. This species breeds in North America and primarily overwinters in Central America and Mexico. YBCH typically nest in the understory of riparian habitat and marsh margins, often in early successional riparian communities (RHJV, 2004). This species generally breeds from early May through early August, with peak activity in June (Green, 2005b). YBCH have been designated as a California SSC.

According to the CNDDB, there were 30 YBCH detections along San Timoteo Creek from 2012 to 2016.

SAWA biologists have observed YBCH nesting in riparian habitat along San Timoteo Creek in every year that they surveyed from 2006 to 2019 (WRC-MSHCP, 2007; 2008; 2009b; 2012b; 2015; and 2020).

WEST YOST 26

Page 2133 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report
Western Yellow -billed Cuckoo
Western yellow -billed cuckoo (YBCU) have not been documented in either San Timoteo Creek or Cooper's Creek. Although the riparian habitat along San Timoteo Creek is of sufficient size and canopy height to support YBCU, this Riparian Zone is very linear and susceptible to edge effect, which may reduce the likelihood of it being occupied by species like YBCU that require large tracts of habitat (WRC-MSHCP, 2015).

Other Special Status Species
In addition to the riparian associated focal species discussed above, the following special status species have been documented within riparian habitats along San Timoteo Creek between the Cooper's Creek/San Timoteo Creek confluence and the Henry N. Wochholz RWRF DP001 outfall:
• MERL
• WTKI
• Southwestern pond turtle (Actinemys pallida)
MERL and WTKI have both been documented utilizing the riparian habitat along San Timoteo Creek for overwintering (WRC-MSHCP, 2010b; 2018a; and 2021a). WTKI have also been documented breeding along San Timoteo Creek and SAWA biologists have observed this species 30 times along San Timoteo Creek since 2005 (WRC-MSHCP, 2018a). MERL has been designated as a Watch List species by the CDFW and the WTKI is a California Fully Protected species.

The federally proposed as threatened southwestern pond turtle (pond turtle) has been documented once within San Timoteo Creek, near the Henry N. Wochholz RWRF DP001 at the westernmost (downstream) end of the Study Area (pers. obs., 2016; CNDDB, 2024). There are no other documented pond turtle observations within San Timoteo Creek, and it is not known how much suitable habitat for this species is currently present along San Timoteo Creek or the current population size. Pond turtles require both aquatic and terrestrial habitats. They use permanent and seasonal aquatic habitats including rivers, sloughs, lakes, reservoirs, ponds, and irrigation canals, with sites for basking, such as rocks, sand, mud, downed logs, submerged branches of near -shore vegetation, and emergent or submerged aquatic vegetation (Western Pond Turtle Range -wide, 2020). Pond turtles move onto land for nesting, overwintering, dispersal, and aestivation. Nesting typically occurs within 100 meters of aquatic habitat in areas with compact well -drained soil, sparse vegetation, and good solar exposure (Western Pond Turtle Range -wide, 2020). Pond turtle nesting may occur in small open areas along trails, levees, roadbeds, fields, grasslands, stream banks, and within utility rights -of -way. Overwintering sites include shrubby/forested areas, the bottom of muddy ponds and other aquatic habitats, and undercut banks along streams (Western Pond Turtle Range -wide, 2020). Many pond turtles overwinter on land at sites up to 500 meters from the water. Overwintering sites tend to have a deep layer of duff or leaf litter under trees or shrubs, and some pond turtles return to the same site each year.

4.3 Existing Biological Resources
Data regarding existing biological resources in the Study Area and Riparian Zone were obtained through literature review, desktop evaluation, and field investigations (discussed as 'Baseline Surveys' below).

Available technical information on the biological resources of the Study Area was reviewed, including previous surveys and recent findings. Spatial data from the WRC-RCA's 2012 updated vegetation maps were obtained from the CDFW's Vegetation Classification and Mapping Program (VegCAMP) to help describe WEST YOST 27

Page 2134 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report
riparian plant communities present within the Riparian Zone. Biological inventory for San Timoteo Creek was obtained from published data of the WRC-RCA and SAWA. Baseline Surveys included:
• Vegetation Sampling Surveys: characterization of the riparian plant communities along Cooper's Creek including total riparian vegetation cover, species richness, and percentage of non-native species cover.
• General Inventory of Biological Resources: literature review along the Cooper's Creek and San Timoteo Riparian Zone utilizing the 2012 WRC-RCA's vegetation map and SAWA biological monitoring reports.
• Focused Protocol Surveys: characterization of presence or absence of two special status riparian associated focal species: LBVI and WIFL.

4.3.1 Methods
Each of the methods is described further in the following subsections.

4.3.1.1 Vegetation Sampling Surveys
Baseline field vegetation sampling surveys were conducted in August of 2024 to characterize vegetation cover, species richness, and percentage of native and non-native species cover within the Cooper's Creek Riparian Zone. Three "Sample Areas" were established along Coopers' Creek (Sample Areas 1,2, and 3) and within each Sample Area a series of 25- to 50 -meter long transects perpendicular to the creek channel were established (Figures 4-1 through 4-3). Using a line -point intercept method, species were recorded at 1 -meter intervals along the sampling transects. A vertical point was projected at each 1 -meter interval and any plant, stem, or canopy intercepting the point was recorded. Average percent cover for each species encountered as well as the total vegetation cover percentage was determined for each transect based on the number of intercepted points divided by the total number of points along the transect (Table 4 -la through 4-1c). The average percent cover for each transect in a given Sample Area was added up and divided by the total number of transects in the Sample Area to provide the average percent cover for the dominant species within each stratum, as well as the overall average vegetation cover within the Sample Area. This data was also used to calculate the percent native and non-native vegetation cover within the three Sample Areas (Table 4-2a through 4-2c). It should be noted that due to overlapping vegetation layers, the sum of absolute cover values for all species may exceed 100 percent.

Native species richness for each transect was determined by adding the total number of species encountered along a transect (Table 4-3a through 4-3c). The number of species recorded along all transects within a given Sample Area was added up and divided by the number of transects within the Sample Area to calculate the overall average native species richness observed within the Sample Area.

Transect endpoint locations were recorded with sub -meter accuracy in ArcGIS Field Maps using an iPhone connected to an E0S Arrow 100 Global Navigation Satellite System (GNSS) device via Bluetooth. Sample Areas were selected based largely on accessibility. No private property or restricted access areas were surveyed. It should be noted that there are several homeless encampments scattered along Cooper's Creek between the Beaumont WWTP DP001 outfall and the 4th Street crossing, and these areas were avoided during the surveys.

WEST YOST 28

Page 2135 of 2775 ends

City of Beaumont
May 2025

Prepared r i
Prepared b'

WEST, YOST
1

Page 2136 of 2775 ends

City of Beaumont
Adoptive Management one!;
Mitlgatfon Plan (AMMP) BEAUMONT
Vegetation Study Area
Survey Sample Areas
Transect Start and End Points
Transect Lines
Vegetation Category
Cattail marshes
Fremont Cottonwood Alliance
Goodding's Willow - Red Willow Alliance
Interior Live Oak Alliance
Red Willow Alliance
Upland habitat and disturbed areas
Baseline Vegetation Sample Area 1
City of Beaumont AMMP
Figure 4-1

Survey
Sample •
Area 2
Prepared b'
W

WEST NYOST

Page 2137 of 2775 ends

Prepared for:

City of Beaumont
Adoptive Management and
M+tigatfnn Plan (AMMP) BEAUMONT
Vegetation Study Area
Survey Sample Areas
Transect Start and End Points
Transect Lines
Vegetation Category
Godding's Willow Association
Goodding's Willow - Red Willow Alliance
Mulefat Alliance
Upland habitat and disturbed areas
■
Baseline Vegetation Sample Area 2
City of Beaumont AMMP
Figure 4.2

Prepared by:
iN FnWEST,, YOST

Page 2138 of 2775 ends

Prepared ft'i
City of Beaumont
Adaptive Mapagementand;�'•
Mitlgatfpn Plan (AMMP) BEA'UIMONT
Vegetation Study Area
Survey Sample Areas
Transept Start and End Points
Transept Lines
Vegetation Category
Godding's Willow Association
Goodding's Willow - Red Willow Alliance
Mulefat Alliance
Upland habitat and disturbed areas
Baseline Vegetation Sample Area 3
City of Beaumont AMMP
Figure 4-3

Table 4-1a. Sample Area 1 - Salix laevigata Forest & Woodland Alliance Percent Cover by Species Species
Transect 1
(50 m)
Transect 2
(50 m)
Transect 3
(50 m)
Transect 4
(50 m)
Transect 5
(50 m)
Transect 6
(50 m)
Average %
Cover
Tree Stratum
Salix laevigata (red willow)
98 50
54 44
46 58

58.33 Salix lasiolepis (arroyo willow)
20 16
8 7.33
Populus fremontii (Fremont cottonwood)
28 4.67
Fraxinus velutina (velvet ash)
22 3.67
Juglans califomica (southern California black walnut)
8 30
24 24

14.33 Ailanthus altissima (tree of heaven)iai
54 9
Shrub Stratum
Baccharis salicifolia (mule fat)
20 3.33
Sambucus mexicana (blue elderberry)
6 6
2 Nicotiana glauca (tree tobacco)ial
10 1.67
Herb Stratum
Datura wrightii (jimsonweed)
2 2
2 1
Urtica dioica (stinging nettle)
8 2
20 12
7 Typha sp. (cattail)
8 1.33
Cyperus eragrostis (tall cyperus)
8 2
2 2
Elymus repens (quack grass)lbl
6 1
Bromus diandrus (ripgut grass)ial
2 0.33
Total Vegetation Cover Percentage)
168
102 86 112 100
134 117
(a) Non-native, Invasive Species
(b) Non-native Species
(c) Due to overlapping vegetation layers, the sum of absolute cover values for all species may exceed 100 percent.

WEST YOST
N -C-1113-80-23.01- W P-R-COOPERSRPT-TABLES

Page 2139 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
-CALIFORNIA-
Table 4-1b. Percent Native and Non-native Cover within Sample Area 1 Transect Number and Length, m
Vegetation Type
Baseline percent Cover
Transect 1 (50 m)
Perennial
Annual
Non-native
Invasive
168
0 54
54 Transect 2 (50 m)
Perennial
Annual
102
0 0
0 Transect 3 (50 m)
Non-native
...............................................................................

Invasive
86 0
0 0
Transect 4 (50 m)
Perennial
Annual
. . . . . . . . . . . . . . . . . . . . . .

Non-native
Invasive
112
0 6
0 Transect 5 (50 m)
Perennial
Annual
Non-native
Invasive ................................................. 100
0 0
0 Transect 6 (50 m)
Perennial
Annual
..........................................

Non-native
Invasive
132
2 12
12 Overall
11 Table 4-1c. Native Species Richness within Sample Area 1 Transect Number Baseline Species Richness
Transect 1
3 Transect 2
5 Transect 3
3 Transect 4
5 Transect 5
7 Transect 6
6 Overall Average

4.83 Total Unique Species
11 WEST YOST
33

Page 2140 of 2775 ends

City of Beaumont
May 2025

Table 4-2a. Sample Area 2 - Salix gooddingii - Salix laevigata Forest & Woodland
Alliance Percent Cover by Species
Species
Transect 1
(50 m)
Transect 2
(50 m)
Transect 3
(25 m)
Transect 4
(25 m)
Average %
Cover
Tree Stratum
Salix gooddingii (Gooding's willow)
54 30
100
28 53
Salix laevigata (red willow)
28 52
84 41
Juglans californica (southern California black walnut)
4 8
3 Shrub Stratum
Baccharis salicifolia (mule fat)
8 2
Nicotiana glauca (tree tobacco)ial
4 1
Herb Stratum
Urtica dioica (stinging nettle)
6 20
24 32

20.5 Cyperus eragrostis (tall cyperus)
6 1.5
Elymus repens (quack grass)(b)
4 1
Woody Vine Stratum
Vitis girdiana (desert wild grape)
100
100
56 92
87 Total Vegetation Cover Percentage)
196
220
180
244
210
(a) Non-native, Invasive Species
(b) Non-native Species
(c) Due to overlapping vegetation layers, the sum of absolute cover values for all species may exceed 100 percent.

WEST YOST
N-01113-LU-23-U1- W P-R-IUUPLRSRPT-TABLES

Page 2141 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
-CALIFORNIA-
Table 4-2b. Percent Native and Non-native Cover within Sample Area 2 Transect Number and Length, m
Vegetation Type
Baseline percent Cover
Transect 1 (50 m)
Perennial
Annual
Non-native
Invasive
196
0 0
Transect 2 (50 m)
Perennial
Annual
Non-native
Invasive
220
0 8
4 Transect 3 (25 m)
Perennial
Annual
Non-native
Invasive
180
0 0
0 Transect 4 (25 m)
Perennial
Annual
Non-native
Invasive
244
0 0
0 ..................................................

Overall
Perennial
Annual
Non-native
................................................

Invasive
210
0 2
1 Table 4-2c. Native Species Richness within Sample Area 2 Transect Number Baseline Species Richness
Transect 1
5 Transect 2
6 Transect 3
3 Transect 4
5 Overall Average

4.75 Total Unique Species
7 WEST YOST 35

Page 2142 of 2775 ends

City of Beaumont
May 2025

Table 4-3a. Sample Area 3 - Salix gooddingii
Forest &
Woodland Alliance
Percent
Cover by Species
Species
Transect 1
(36 m)
Transect 2
(50 m)
Transect 3
(50 m)
Transect 4
(50 m)
Transect 5
(50 m)
Average %
Cover
Tree Stratum
Salix gooddingii (Gooding's willow)

11.11 74
18 46

29.82 Salix laevigata (red willow)
50 10
Populus fremontii (Fremont cottonwood)
10 14
10 26
12 Platanus racemosa (western sycamore)
8 46

10.8 Ulmus pumila (Siberian elm)(a)
2 10
18 6
Prunus cerasifera (cherry plum)(b)
10 2
Washingtonia robusta (Mexican fan palm)(b)
10 2
Juglans califomica (southern California black walnut)
26 5.2
Shrub Stratum I I
Baccharis salicifolia (mule fat)

16.67 24
2 8
12 12.53
Baccharis pilularis (coyote bush)
6 1.2
Salix lasiolepis (arroyo willow)

33.33 10
24 28
8 20.66
Salix exigua (sandbar willow)

5.56 1.11
Sambucus mexicana (blue elderberry)
10 10
4 4.8
Artemisia californica (California sagebrush)
4 12

3.2 Eriogonum fasciculatum (California buckwheat)
6 6

2.4 Herb Stratum
Urtica dioica (stinging nettle)

11.11 2
10 8

6.22 Oenothera elata (evening primrose)
4 12
26 8.4
Erigeron canadensis (Canada horseweed)
4 2
2 1.6
Ambrosia psilostachya (western ragweed)
2 2

0.8 Heterotheca grandiflora (telegraph weed)
2 0.4
Datura wrightii (jimsonweed)
6 1.2
Marrubium vulgare (white horehound)(b)
2 0.4
Plantago major (common plantain)(a)
2 0.4
Juncus acutus (spiny rush)
6 4
2 Cyperus eragrostis (tall cyperus)
2 0.4
Typha sp. (cattail)
2 0.4
Elymus repens (quack grass)(a)
12 4

3.2 Bromus diandrus (ripgut grass)(b)
8 1.6
Woody Vine Stratum
Vitis girdiana (desert wild grape)

63.89 58
56 28
56 52.38
Rubus armeniacus (Himalayan blackberry)(b)
42 8.4
Total Vegetation Cover Percentage(`)
191.67
270
180
186
230
211.52
(a) Non-native Species
(b) Non-native, Invasive Species
(c) Due to overlapping vegetation layers, the sum of absolute cover values for all species may exceed 100 percent.

WEST YOST

Page 2143 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
-CALIFORNIA-
Table 4-3b. Percent Native and Non-native Cover within Sample Area 3 Transect Number and Length, m
Vegetation Type
Baseline percent Cover
Transect 1 (36 m)
Perennial
..............................

Annual
Non-native
Invasive
191.67
0 0
Transect 2 (50 m)
178
Transect 3 (50 m)
Perennial
Annual
Non-native
Invasive
2 10
0 Transect 4 (50 m)
Perennial
Annual
Non-native
Invasive
184
2 26
2 Transect 5 (50 m)
Perennial
Annual
Non-native
Invasive
230
0 20
20 Overall
Perennial
Annual
Non-native
Invasive
207.93

3.6 24

14.4 Table 4-3c. Native Species Richness within Sample Area 3 Transect Number Baseline Species Richness
Transect 1
7 Transect 2
13 Transect 3
10 Transect 4
12 Transect 5
12 Overall Average

8.4 Total Unique Species 22

WEST YOST
37

Page 2144 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

4.3.1.2 General Inventory of Biological Resources
Figure 4-1 through 4-3 depict the areas within the Cooper's Creek Riparian Zone that were sampled by HDR biologists in August of 2024 and riparian plant communities within these areas were mapped according to the results of the baseline field vegetation sampling surveys. The riparian plant communities present along the remainder of Cooper's Creek and San Timoteo Creek were mapped in accordance with the WRC-RCA's 2012 updated vegetation maps are included in Table 4-4. Wildlife species observed within the Cooper's Creek Riparian Zone during the 2024 surveys conducted by HDR are included in Table 4-5.

Section 4.2.2.2 of this report describes the wildlife species documented within the San Timoteo Creek portion of the Study Area during the SAWA biological monitoring efforts that occurred from 2004 to 2022.

4.3.1.3 Focused Protocol Surveys
The focused protocol LBVI and WIFL presence/absence surveys were conducted by HDR biologist Adam Lockyer (Permitted Biologist, TE55135D-0) in accordance with the U.S. Fish and Wildlife Service (USFWS) survey protocols for these species. However, during the first round of LBVI surveys conducted on April 25, 2024, LBVI were detected throughout all three of the survey areas. Following the confirmation of the presence of LBVI during the first survey, subsequent surveys were canceled because the purpose of the surveys was to determine only the presence or absence of LBVI in the survey areas. Five total protocol WIFL surveys were conducted from May 16 to July 5, 2024. After accessing Survey Area 1 on April 25, locks were placed on all gates with access to the survey area. No other probable access was possible, and the fence precluded any future surveys of this area. Subsequent WIFL surveys were conducted in Survey Areas 2 and 3 (Appendix B — LBVI-WFL Survey Report).

During each of the surveys, the biologist walked slowly along the edge of riparian habitat, stopping at 60 - to 100 -foot intervals to listen for LBVI and WIFL. During the WIFL surveys, a recording of WIFL vocalizations was played at 60- to 100 -foot intervals along the survey route. The surveying biologist, with the aid of binoculars for viewing wildlife species, waited for several minutes after each playback to look and listen for WIFL. Surveys for LBVI were conducted by stopping at similar intervals along the survey route to watch and listen for LBVI. All surveys were completed between dawn and 11:00 AM for LBVI and by 10:30 AM for WIFL. No surveys were conducted during extreme weather conditions (i.e., winds exceeding 15 miles per hour, rain, or temperatures in excess of 95 degrees Fahrenheit).

4.3.2 Cooper's Creek
The following subsections describe the existing plant communities and wildlife observed in the Riparian Zone of Cooper's Creek.

4.3.2.1 Riparian Plant Communities
Figures 4-4a through 4-4j are a series of ten maps that delineate the mapped extent of riparian plant communities along Cooper's Creek to its confluence with San Timoteo Creek. A total of seven riparian plant communities were mapped within the Cooper's Creek Riparian Zone:
• Baccharis salicifolia Shrubland Alliance (Mulefat Alliance) • Populus fremontii Forest and Woodland Alliance (Fremont Cottonwood Alliance) • Populus fremontii — Salix (laevigata, Iasiolepis, lucida ssp. Iasiandra) Association (Fremont Cottonwood / Willow spp. Association)
• Salix laevigata Forest and Woodland Alliance (Red Willow Alliance) WEST YOST 38

Page 2145 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
• Salix gooddingii Forest and Woodland Alliance (Gooding's Willow Association) • Salix gooddingii — Salix Iaevigata Forest and Woodland Alliance (Gooding's Willow — Red Willow Alliance)
• Typha (angustifolia, domingensis, latifolia) Herbaceous Alliance (Cattail Marshes) Two additional upland habitats were mapped adjacent the Riparian Zone for their proximity to the Riparian Zone and importance as potentially suitable foraging, breeding, and/or sheltering habitat for riparian associated wildlife species; these habitats appear in Figures 4-4a through 4-4c:
• Quercus wislizeni Forest and Woodland Alliance (Interior Live Oak Alliance) • Non-native Eucalyptus spp. Groves
The current average width of the Cooper's Creek Riparian Zone is approximately 47 meters. The average width of the wetted portion of the stream channel (i.e., the portion of the channel with active surface flow) across all three Sample Areas was 3 meters at the time of survey. A characterization of the riparian plant communities identified within the three Sample Areas of the Cooper's Creek portion of the Study Area, including dominant species, baseline vegetation cover, species richness, and percentage of non-native species, is provided below.

Riparian Zone Sample Area 1
Sample Area 1 is located immediately downstream (west) of the Beaumont WWTP DP001 outfall and consists of six 50 -meter long transects situated perpendicular to the active stream channel (Figure 4-1).

The plant community identified within this sample area is Salix laevigata Forest and Woodland Alliance or "red willow alliance." The dominant species in the tree stratum within this riparian habitat is red willow, with an overall average cover of 58.33 percent observed in Sample Area 1 (Table 4-1a). The dominant species in the shrub stratum is mulefat, with an average cover of 3.33 percent, and the dominant herbaceous species within Sample Area 1 is stinging nettle, with an overall average cover of 7 percent.

There was no woody vine stratum encountered on any of the transects in Sample Area 1. The shrub and herbaceous cover are sparse throughout most of this portion of the Cooper's Creek Riparian Zone due to the dense, closed canopy that characterizes this habitat within the Study Area. The red willow alliance that comprises the riparian habitat in Sample Area 1 is a mature or late seral stage riparian habitat, with only 12 percent bare ground and most of the ground cover consisting of woody debris. The tree canopy within this plant community is typically less than 30 meters in height (CNPS, 2024). Other native species conspicuous within Sample Area 1 include southern California black walnut and arroyo willow (Table 4-1a). Approximately 9.29 acres of red willow alliance riparian habitat exists within the Cooper's Creek portion of the Study Area.

The vegetation cover in Sample Area 1 consisted of an overall average of 116.67 percent perennial species cover and only 0.33 percent annual species cover (Table 4-2a). The overall baseline percent cover of non- native species within Sample Area 1 was 12 percent, with 11 percent invasive species cover. Invasive species present within Sample Area 1 included tree of heaven (Ailanthus altissima), tree tobacco (Nicotiana glauca), and ripgut grass (Bromus diandrus).

The red willow alliance habitat in Sample Area 1 is more species rich than the downstream Sample Area 2, but less species rich than the downstream Sample Area 3. The overall baseline species richness in Sample Area 1 was 11 native species, with an average native species richness of 4.83 species per transect (Table 4-3a).

WEST YOST 39

Page 2146 of 2775 ends

City of Beaumont
May 2025

Prepared for:

Prepared by:

WIN EST EN
0 200
400
Feet

Page 2147 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Eucalyptus Groves
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4a

Prepared for:

Prepared by:

WEST
0 200
400
Feet

Page 2148 of 2775 ends

City of Beaumont ,�
Adaptive Management and , -/=;• ,
Mitigation Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Cattail marshes
Eucalyptus Groves
Fremont Cottonwood Alliance
Red Willow Alliance
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4b

Prepared for:

Prepared by:

WIN EST EN
0 200
400
Feet

Page 2149 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Goodding's Willow - Red Willow Alliance
Interior Live Oak Alliance
Red Willow Alliance
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4c

Prepared by:

WV�IOST EN
o
200
400
Feet

Page 2150 of 2775 ends

Prepared for:

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Goodding's Willow - Red Willow Alliance
Upland habitat and disturbed areas
Morongo Golf
Club
Oak Valley Golf
Club
Sa
Beaumont
E 6th
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4d

Prepared by:

WEST OST
0 200
400
Feet

Page 2151 of 2775 ends

Prepared for:

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Goodding's Willow - Red Willow Alliance
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4e

Prepared by:

W w OST EEST n
0 200
400
Feet

Page 2152 of 2775 ends

Prepared for:

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Goodding's Willow - Red Willow Alliance
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4f

Prepared by:

WEST
0 200
400
Feet

Page 2153 of 2775 ends

Prepared for:

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Godding's Willow Association
Goodding's Willow - Red Willow Alliance
Mulefat Alliance
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4g

Prepared by:

WIN EST En
0 200
400
Feet

Page 2154 of 2775 ends

Prepared for:

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
Godding's Willow Association
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4h

Prepared by:

WEST
0 200
400
Feet

Page 2155 of 2775 ends

Prepared for:

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
Upland habitat and disturbed areas
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4i

Prepared for:

Prepared by:

WIN EST EN
200
400
Feet

Page 2156 of 2775 ends

City of Beaumont -- \
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
Mulefat Alliance
Red Willow Alliance
Upland habitat and disturbed areas
IMF
Cooper's Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-4j

Table 4-4. List of Plant
Species Observed
Scientific Name
Common Name
Lifeform
CNPS Rank"
Cal-IPC Rating(b)
Apocynaceae
Dogbane Family
Apocynum cannabinum
Indian hemp
perennial herb
--
--
Arecaceae
Palm Family
I
Washingtonia robusta (`i
Mexican fan palm(`)
tree
--
moderate
Asteraceae
Aster Family
I
Ambrosia psilostachya
ragweed
perennial herb
--
--
Artemisia californica
California sagebrush
shrub
--
Artemisia douglasiana
California mugwort
perennial herb
--
--
Artemisia dracunculus
tarragon
perennial herb
--
--
Baccharis pilularis
coyote bush
shrub
--
--
Baccharis salicifolia
mulefat
shrub
--
--
Centaurea melitensis (`)
Tocalote(`)
annual herb
--
moderate
Erigeron canadensis
Canada horseweed
annual herb
--
--
Heterotheca grandiflora
telegraph weed
annual or perennial herb
--
--
Lactuca serriola (d)
prickly lettuce(d)
annual herb
--
--
Silybum marianum icl
milk thistle(d)
annual or perennial herb
--
limited
Sonchus oleraceus (di
sow thistle(d)
annual herb
--
--
Xanthium strumarium
cockleburr
annual herb
--
--
Brassicaceae
Mustard Family
Hirschfeldia incana (`l
short podded mustard(`)
perennial herb
--
moderate
Chenopodiaceae
Goosefoot Family
Salsola tragus(`i
Russian thistle(`)
annual herb
--
limited
Cucurbitaceae
Gourd Family
Cucurbita foetidissima
Missouri gourd
perennial herb or vine
--
--
Cyperaceae
Sedge Family
Cyperus eragrostis
tall flatsedge
perennial herb
--
--
Euphorbiaceae
Spurge Family
Croton setiger
turkey -mullein
annual herb
--
--
Juglandaceae
Walnut Family
Juglans californica
southern California black walnut
tree

4.2 (limited distribution)
--
Juncaceae
Rush Family
Juncus acutus
spiny rush
perennial herb
--
--
Lamiaceae
Mint Family
Marrubium vulgare (`)
white horehound(`)
perennial herb
--
limited
Moraceae
Mulberry Family
Morus alba (d)
white mulberry(d)
tree
--
--
Myrtaceae
Myrtle Family
Eucalyptus camaldulensis(c)
red gum(`)
tree
--
limited
Oleaceae
Olive Family
Fraxinus velutina
velvet ash
tree
--
--
Onagraceae
Evening Primrose Family
Oenothera elata
evening primrose
perennial herb
--
Papaveraceae
Poppy Family
Argemone munita
Chicalote
annual or perennial herb
--
--
Plantaginaceae
Plantain Family
Plantago major(d)
common plantainld)
perennial herb
--
--
Platanaceae
Plane Family
Platanus racemosa
California sycamore
tree
--
Poaceae
Grass Family
Arundo donax (`)
giant reed(`)
perennial grass
--
high
Avena barbata (`i
slender oat(`)
annual grass
--
moderate
Avena fatua (c)
wild oat(`)
annual grass
--
moderate
Bromus diandrus (`)
ripgut brome(`)
annual grass
--
moderate
Bromus madritensis (dl
foxtail chess(d)
annual grass
--
--
Elymus repens (d)
quack grass"d)
perennial grass
--
--
Polypogon monspeliensis (c)
annual beard grass(`)
annual grass
--
limited
Polygonaceae
Knotweed Family
I
Eriogonum fasciculatum
California buckwheat
shrub
--
--
Rosaceae
Rose Family
Prunus cerasifera (`I
cherry plum(`)
tree
--
limited
Rubus armeniacus (c)
Himalayan blackberry(`)
shrub
--
high
Rubiaceae
Bedstraw Family
•
_
Galium aparine
cleavers
annual herb
--
--
Salicaceae
Willow Family
I

Populus fremontii
Fremont cottonwood
tree
--
--
Salix exigua
sandbar willow
tree or shrub
--
--
Salix gooddingii
Gooding's willow
tree
--
--
Salixlaevigata
red willow
tree
--
--
Salix lasiolepis
arroyo willow
tree or shrub
--
--
Simaroubaceae
Quassia Family
Ailanthus altissima (`I
tree of heaven(`)
tree
--
moderate
Solanaceae
Nightshade Family
Datura wrightii
jimsonweed
perennial herb
--
--
Nicotiana glauca (c)
tree tobacco(`)
tree or shrub
--
moderate
Nicotiana acuminata var. multiflora (d)
many flowered tobacco(d)
annual herb
--
--
Typhaceae
Cattail Family
Typha sp.
cattail
perennial aquatic herb
--
--
Ulmaceae
Elm Family
Ulmus pumila (d)
Siberian elm"
tree
--
--
Urticaceae
Nettle Family
Urtica dioica
stinging nettle
perennial herb
--
--
Vitaceae
Grape Family
Vitis girdiana
Southern california grape
vine or shrub
--
--
Viburnaceae
Viburnum Family
Sambucus mexicana
elderberry
tree or shrub
--
--
(a) Cal-IPC = California Invasive Plant Council
(b) CNPS = California Native Plant Council
(c) Non-native, Invasive Species
(d) Non-native Species

WEST YOST

Page 2157 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Table 4-5. List of Wildlife Species Observed
Scientific Name
Riparian Habitat
Common Name Listing Status Federal/ State Other Status Focal Species BIRDS
Accipitridae
Hawk Family
Accipitercooperii
Cooper's Hawk
--
CDFW: WL(a'b)
--
Accipiterstriatus
Sharp -shinned Hawk
--
CDFW: WL
--
Buteojamaicensis
Red-tailed Hawk
--
--
--
Buteo lineatus
Red -shouldered Hawk
--
--
--
Aegithalidae
Bushtit Family
Psaltriparus minimus
Bushtit
—
--
--
Anatidae
Swan, Goose, and Duck Family
Anus platyrhynchos
Mallard
--
--
--
Cathartidae
New World Vulture Family
Cathartes aura
Turkey Vulture
--
--
--
Charadriidae
Plover Family
Charadrius vociferus
Killdeer
--
--
--
Columbidae
Pigeon and Dove Family
__
Columba livia 14
Rock Pigeon(`)
--
--
--
Zenaida macroura
Mourning Dove
--
--
--
Corvidae
Jay and Crow Family
J
Aphelocoma californica
California Scrub -Jay
--
--
--
Corvus corax
Common Raven
--
--
—
Falconidae
Falcon Family
Falco sparverius
American Kestrel
--
--
—
Fringillidae
Finch Family
Haemorhous mexicanus
House Finch
--
--
—
Spinus psaltria
Lesser Goldfinch
—
--
--
Spinus tristis
American Goldfinch
--
--
—
Icteridae '
Blackbird and Oriole Family
Icterus bullockii
Bullock's Oriole
USFWS: BCC(d)
—
Icterus cucullatus
Hooded Oriole
--
--
--
Molothrus ater
Brown -headed Cowbird
--
--
--
Mimidae
Mockingbird and Thrasher Family
Toxostoma redivivum
California Thrasher
--
USFWS: BCC
--
Odontophoridae
New World Quail Family
Callipepla californica
California Quail
--
--
--
Parulidae
Wood -warbler Family
Geothlypis trichas
Common Yellowthroat
--
--
Yes
Liothlypis celata
Orange -crowned Warbler
--
--
--
Setophaga nigrescens
Black -throated Gray Warbler
--
USFWS: BCC
--
Setophaga petechia
Yellow Warbler
--
CDFW: SSC(e)
Yes
Passerellidae
New World Sparrow Family
Artemisiospiza belli
Bell's Sparrow
--
CDFW: WL
—
Chondestes grammacus
Lark Sparrow
--
--
--
Melospiza melodia
Song Sparrow
--
--
Yes
Melozone crissalis
California Towhee
--
--
--
Pipilo maculatus
Spotted Towhee
--
--
—
Zonotrichia leucophrys
White -crowned Sparrow
--
--
--
Picidae
Woodpecker Family
Colaptes auratus
Northern Flicker
--
--
--
Melanerpesformicivorus
Acorn Woodpecker
--
--
—
Picoides nuttallii
Nuttall's Woodpecker
--
USFWS: BCC
--
Ptiliogonatidae
Silky Flycatcher Family
1 Phainopepla nitens
Phainopepla
--
USFWS: BCC
--
Rallidae
Rail and Coot Family
Fulica americana
American Coot
--
--
--
Strigidae
Owl Family
Bubo virginianus
Great Horned Owl
--
--
--
Sturnidae
Starling Family
Sturnus vulgaris*
European Starling*
--
--
--
Sylviidae
Silviid Warblers Family
Chamaea fasciata
Wrentit
--
USFWS: BCC
--
Threskiornithidae
Ibis and Spoonbill Family
Plegadis chihi
White-faced Ibis
--
CDFW: WL
--
Trochilidae
Hummingbird Family
Calypte anna
Anna's Hummingbird
--
--
--
Selasphorus sasin
Allen's Hummingbird
--
USFWS: BCC
--
Troglodytidae
Wren Family
Thryomanes bewickii
Bewick's Wren
Tyrannidae
Tyrsnt Flycatcher Family
Empidonax traillii (migrant)
Willow Flycatcher (migrant)
--
--
Yes
Sayornis saya
Say's Phoebe
--
--
--
Sayornis nigricans
Black Phoebe
--
--
—
Tyrannus verticalis
Western Kingbird
--
--
--
Vireonidae
Vireo Family

Vireo bellii pusillus
Least Bell's Vireo
Endangered/ Endangered
--
Yes

REPTILES
Phrynosomatidae
North American
Spiny Lizard Family
Sceloporus occidentalis longipes
Great Basin Fence Lizard
--
--
--
Uta stansburiana elegans
Western Side -blotched Lizard
--
--
--
Teiidae
Whiptail and Racerunner Family
Aspidoscelis tigris stejnegeri
San Diegan Tiger Whiptail
--
CDFW: SSC
--
Viperidae
Viper Family
Crotalus oreganus helleri
Southern Pacific Rattlesnake
--
--
--

MAMMALS
Cricetidae
Hamsters, Voles, Lemmings, New
World Mice and Rat Family
Neotoma macrotis
Big -eared Woodrat
--
--
--
Felidae
Feline Family
Lynx rufus
Bobcat
--
--
--
Geomyidae
Pocket Gopher Family
Thomomys bottae
Botta's Pocket Gopher
--
--
--
Leporidae
Rabbit and Hare Family
Sylvilagus audubonii
Desert Cottontail
--
--
--
Sciuridae
Squirrel Family
Otospermophilus beecheyi
California Ground Squirrel
--
--
--
(a) CDFW = California Department of Fish and Wildlife
(6) WL = Watch List
(c) Non-native, introduced
(d) USFWS: BCC
(e) CDFW: SSC

WEST YOST

Page 2158 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
The current average width of the Riparian Zone in Sample Area 1 is approximately 53 meters. The average width of the wetted portion of the stream channel (i.e., the portion of the channel with active surface flow) within Sample Area 1 was 2 meters at the time of survey.

Riparian Zone Sample Area 2
Sample Area 2 is located upstream (east) of where 4th Street crosses Cooper's Creek and consists of two 50 -meter long transects and two 25 -meter long transects situated perpendicular to the active stream channel (Figure 4-2). The plant community identified within this sample area is Salix gooddingii — Salix laevigata Forest and Woodland Alliance or "Gooding's willow— red willow alliance." The dominant species in the tree stratum within this riparian habitat are Gooding's willow and red willow, with an overall average cover of 53 percent for Gooding's willow and 41 percent for red willow observed in Sample Area 2 (Table 4-1b). The dominant species in the shrub stratum are mulefat and tree tobacco, with an average cover of only 2 and 1 percent, respectively. The dominant herbaceous species within Sample Area 2 is stinging nettle, with an overall average cover of 20.5 percent. There is also a woody vine stratum consisting entirely of desert wild grape (Vitis girdiana), with an overall average cover of 87 percent. The shrub cover is sparse throughout most of this portion of the Cooper's Creek Riparian Zone due to the dense, closed canopy and high percent cover of woody vines that characterizes this habitat within the Study Area. The Gooding's willow — red willow alliance that comprises the riparian habitat in Sample Area 2 is a mature or late seral stage riparian habitat, with 0 percent bare ground and most of the ground cover consisting of woody debris and desert wild grape. The tree canopy within this plant community is typically less than 30 meters in height (CNPS 2024). Approximately 21.3 acres of Gooding's willow — red willow alliance riparian habitat exists within the Cooper's Creek portion of the Study Area.

The vegetation cover in Sample Area 2 consisted of an overall average of 210 percent perennial species cover, with no annuals (Table 4-2b). The overall baseline percent cover of non-native species within Sample Area 2 was 2 percent, with 1 percent invasive species cover. The only invasive species present within Sample Area 2 was tree tobacco.

The Gooding's willow — red willow alliance habitat in Sample Area 2 had the lowest species richness of all three areas sampled. The overall baseline species richness in Sample Area 2 was 7 native species, with an average native species richness of 4.75 species per transect (Table 4-3b).

Sample Area 2 had the narrowest Riparian Zone of all three areas sampled. The current average width of the Riparian Zone in Sample Area 2 is approximately 46 meters. The average width of the wetted portion of the stream channel (i.e., the portion of the channel with active surface flow) within Sample Area 2 was approximately 5.7 meters at the time of survey.

Riparian Zone Sample Area 3
Sample Area 3 is located downstream (west) of where 4th Street crosses Cooper's Creek and consists of four 50 -meter long transects and one 36 -meter long transect situated perpendicular to the active stream channel (Vegetation Sampling Figure 4-3). The plant communities identified within this sample area are Salix gooddingii Forest and Woodland Alliance or "Gooding's willow association" and Baccharis salicifolia Shrubland Alliance or "mulefat alliance." The mulefat alliance habitat present within Sample Area 3 was not sampled but was qualitatively assessed. This plant community consists of a continuous shrub canopy that is less than 5 meters in height (CNPS 2024). The dominant species in this plant community is mulefat, with little to no herbaceous layer and only scattered emergent Fremont cottonwoods and willows.

Approximately 0.44 acres of mulefat alliance riparian habitat exists within the Cooper's Creek portion of the Study Area.

WEST YOST 52

Page 2159 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
The dominant species in the tree stratum within the Gooding's willow association habitat present in Sample Area 3 is Gooding's willow, with an overall average cover of 29.82 percent observed in Sample Area 3 (Table 4-1c). The dominant species in the shrub stratum are arroyo willow and mulefat, with an average cover of 20.66 and 12.53 percent, respectively. The dominant herbaceous species within Sample Area 3 are evening primrose (Oenothera elata) and stinging nettle, with overall average covers of 8.4 and

6.22 percent, respectively. There is also a woody vine stratum dominated by desert wild grape, with an overall average cover of 52.38 percent. Other native species conspicuous within Sample Area 3 include Fremont cottonwood, California sycamore (Platanus racemosa), and red willow (Table 4-1c).

Approximately 10.4 acres of Gooding's willow alliance riparian habitat exists within the Cooper's Creek portion of the Study Area.

The Gooding's willow association in Sample Area 3 is more complex in structure than the riparian habitats in Sample Areas 1 and 2, ranging from shrub and herbaceous dominated early and mid-seral stage habitat along the outer edges of the Riparian Zone, to mature, late seral stage riparian habitat closest to the active stream channel. The more complex vegetation structure observed within Sample Area 3 is due to habitat restoration/enhancement efforts that began in 2021 and included planting of various riparian species along the edges of the existing Gooding's willow association habitat. There is less ground cover within the early to mid-seral stage areas of the riparian habitat in Sample Area 3, with a higher density of shrubs and herbaceous species present. Whereas the ground cover within the late seral stage interior of the Sample Area 3 Riparian Zone consists mostly of downed woody debris and woody vines. The canopy height within Sample Area 3 ranges from less than 5 meters to over 30 meters.

The vegetation cover in Sample Area 3 consisted of an overall average of 207.9 percent perennial species cover and 3.6 percent annual species cover (Table 4-2c). The overall baseline percent cover of non-native species within Sample Area 3 was 24 percent, with 14.4 percent invasive species cover.

Invasive species present within Sample Area 3 included cherry plum (Prunus cerasifera), Mexican fan palm (Washingtonia robusta), white horehound (Marrubium vulgare), ripgut grass, and Himalayan blackberry (Rubus armeniacus).

The Gooding's willow association habitat in Sample Area 3 had the highest species richness of all three areas sampled. The overall baseline species richness in Sample Area 3 was 22 native species, with an average native species richness of 8.4 species per transect (Table 4-3c).

Sample Area 3 had the widest Riparian Zone of all three areas sampled, due to the recent restoration/enhancement efforts and plantings. The current average width of the Riparian Zone in Sample Area 3 is approximately 64 meters. The average width of the wetted portion of the stream channel (i.e., the portion of the channel with active surface flow) within Sample Area 3 was approximately

2.5 meters at the time of survey.

Summary of All 3 Sample Areas
A total of 55 plant species were identified within the Cooper's Creek Riparian Zone including 31 native species and 24 non-native species, 16 of which are considered invasive species by the California Invasive Plant Council (CAL-IPC). Additionally, one special status species was observed — southern California black walnut (Juglans californica) — which has a California Native Plant Society (CNPS) ranking of 4.3 for its limited distribution in the state. A complete list of all riparian plant species observed within the Cooper's Creek Riparian Zone during the 2024 baseline year is provided in Table 4-4.

WEST YOST 53

Page 2160 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

4.3.2.2 Wildlife
Wildlife species were detected during 2024 baseline year field surveys by sight, calls, tracks, scat, and/or other sign. A total of 57 wildlife species (48 birds, four reptiles, five mammals) were observed within the Cooper's Creek Riparian Zone, including seven USFWS Birds of Conservation Concern (BCC), four CDFW "Watch List" species, two CDFW SSC, one state listed as endangered species (WIFL), and one state and federally listed endangered species (LBVI). Additionally, the following five riparian associated focal species were observed within the Cooper's Creek portion of the Study Area:
• LBVI
• WIFL
• YEWA
• Common Yellowthroat (COYE)
• Song Sparrow (SOSP)
A complete list of all wildlife species observed within the Cooper's Creek Riparian Zone during the 2024 baseline year is provided in Table 4-5.

Least Bell's Vireo
HDR biologists observed four LBVI within the Riparian Zone during the 2024 baseline focused LBVI presence/absence survey conducted on April 25, 2024. An additional six (10 total) LBVI were observed incidental to the focused protocol WIFL presence/absence survey visits (Appendix B — LBVI-WFL Survey Report). LBVI were also heard calling from all three Sample Areas during the 2024 baseline year vegetation surveys.

Willow Flycatcher
HDR biologists observed one WIFL in Survey Area 2 on June 4, 2024 during the 2024 baseline focused WIFL presence/absence survey (Appendix B— LBVI-WFL Survey Report). No other detections of WIFL were made during other survey visits and no nesting was observed. Because this individual was not detected during subsequent visits during the nesting survey windows, this one observation of a WIFL is not considered to be the southwestern willow flycatcher subspecies. All observations of WIFL and LBVI during focused presence/absence surveys conducted by HDR biologists for these species, along with the dates of observations, are included in Figures B-1, B-2, and B-3 of Appendix B — LBVI-WFL Survey Report. It should also be noted that HDR biologists observed an Empidonax flycatcher within riparian habitat near Sample Area 1 during baseline vegetation surveys conducted in late August of 2024, but were not able to identify it to species.

Yellow Warbler
HDR biologists observed multiple YEWA in red willow alliance riparian habitat with an understory of cattail marshes near the Beaumont WWTP DP001 outfall during the 2024 baseline year vegetation surveys conducted in late August of 2024.

WEST YOST 54

Page 2161 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
Common Yellowthroat
The COYE is a small migratory songbird that is yellow and olive colored with a broad black mask. This species primarily breeds in North America and overwinters in Central America and Mexico but is also a year-round resident in parts of North America and Mexico, including southern California (Green, 1990b).

COYE typically nest in the understory (usually within 8 centimeters off the ground) of wet meadows, freshwater emergent wetlands, saline emergent wetlands, and valley foothill riparian habitats (Green, 1990b; RHJV, 2004). This species generally breeds from early April to mid -July, with peak activity in May and June (Green, 1990b).

HDR biologists observed multiple COYE in cattail marsh habitat near the Beaumont WWTP DP001 outfall during the 2024 baseline year vegetation surveys conducted in late August of 2024.

Song Sparrow
The SOSP is a small migratory songbird that is russet and gray colored, with bold streaks down its white chest. Although some populations of this species breed in Canada and the northern United States and overwinter in the southern United States and Mexico, most that breed in California are year-round residents (Green, 1990c). SOSP nest in the understory (usually on the ground or within 1.3 meters off the ground) of early seral stage riparian habitats, wetlands, coastal scrub habitats, and marshes (Green, 1990c; RHJV, 2004). They require low, dense vegetation for protective cover, usually near water, in emergent vegetation, or in other moist areas (Green, 1990c).

HDR biologists observed multiple SOSP in all three Sample Areas during the 2024 baseline year vegetation surveys conducted in late August of 2024.

4.3.3 San Timoteo Creek
The following subsections describe the existing plant communities in the Riparian Zone of San Timoteo Creek. Records of wildlife usage of the San Timoteo Creek Riparian Zone were obtained from the SAWA biological monitoring reports for surveys conducted from 2004 through 2022 as part of the WRC-RCA's Biological Monitoring Program, as well as from the CNDDB. Known wildlife usage of the San Timoteo Creek Riparian Zone is discussed in Section 4.2.2.2 of this report (above). Therefore, no further discussion of wildlife usage of the San Timoteo Creek Riparian Zone is included below.

4.3.3.1 Riparian Plant Communities
Figures 4-5a through 4-5m are a series of 13 maps that delineate the mapped extent of riparian plant communities along the San Timoteo Creek Riparian Zone from the Cooper's Creek/San Timoteo Creek confluence to the Henry N. Wochholz RWRF DP001 outfall. A total of six riparian plant communities were mapped within the San Timoteo Riparian Zone :
• Baccharis salicifolia Shrubland Alliance (Mulefat Alliance) • Populus fremontii — Baccharis salicifolia Association (Fremont Cottonwood / Mulefat Association) • Populus fremontii Forest and Woodland Alliance (Fremont Cottonwood Alliance) • Populus fremontii — Salix (laevigata, lasiolepis, lucida ssp. lasiandra) Association (Fremont Cottonwood / Willow spp. Association)
• Populus fremontii —Salix laevigata Association (Fremont Cottonwood / Red Willow Association) • Salix laevigata Forest and Woodland Alliance (Red Willow Alliance) WEST YOST 55

Page 2162 of 2775 ends

City of Beaumont
May 2025

Prepared for:

Prepared by:

WIN EST EN
0 250
500
Feet

Page 2163 of 2775 ends

City of Beaumont -- \
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Mulefat Alliance
Red Willow Alliance
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5a

Prepared for:

Prepared by:

WEST
250
500
Feet

Page 2164 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Red Willow Association
Mulefat Alliance
Red Willow Alliance
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5b

Prepared for:

Prepared by:

WIN EST En
0 250
500
Feet

Page 2165 of 2775 ends

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Red Willow Association
Upland and Disturbed Areas
T
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5c

Prepared for:

Prepared by:

WEST
0 250
500
Feet

Page 2166 of 2775 ends

City of Beaumont Adaptive Management and G,=;•V
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Red Willow Association
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5d

Prepared for:

Prepared by:

WIN EST EN
25u
500
Feet

Page 2167 of 2775 ends

City of Beaumont -\
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
AMFremont Cottonwood - Red Willow Association
r Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5e

Prepared for:

Prepared by:

WIN EST EN
0 250
50 0
Feet

Page 2168 of 2775 ends

4LH1
Crenshaw St
City of Beaumont -\
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
din Fremont Cottonwood - Red Willow Association
T Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5f

Prepared for:

Prepared by:

WIN EST EN
0 250
500
Feet

Page 2169 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
din Fremont Cottonwood - Red Willow Association
T Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5g

Prepared for:

Prepared by:

WIN EST En
0 250
500
Feet

Page 2170 of 2775 ends

City of Beaumont ,�
Adaptive Management and , -/=;• ,
Mitigation Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Red Willow Association
Fremont Cottonwood / Mulefat Association
Upland and Disturbed Areas
U
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5h

Prepared for:

Prepared by:

WIN EST EN
0 250
500
Feet
San Timoteo Canyon Rd

Page 2171 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood / Mulefat Association
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5i

Prepared for:

Prepared by:

WIN EST EN
0 250
500
Feet

Page 2172 of 2775 ends

Vegetation Study Area
Vegetation Category
Fremont Cottonwood / Mulefat Association
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont
Adaptive Management and Cam'"l City of Beaumont AMMP
Mitigation Plan (AMMP) BEAUMONT
Figure 4-5j

Prepared for:

Prepared by:

WEST
San=Timoteg_ Canyon Rd
250
500
Feet

Page 2173 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
Fremont Cottonwood / Mulefat Association
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5k

Prepared by:
0 WEST
250
Feet
500

Page 2174 of 2775 ends

Prepared for:

Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
AFremont Cottonwood / Mulefat Association
Fremont Cottonwood Alliance
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont
Adaptive Management and Cam'"l City of Beaumont AMMP
Mitigation Plan (AMMP) BEAUMONT
Figure 4-51

Prepared for:

Prepared by:

WIN EST EN
0 250
500
Feet

Page 2175 of 2775 ends

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Vegetation Study Area
Vegetation Category
Fremont Cottonwood - Willow spp. Association
Fremont Cottonwood / Mulefat Association
Mulefat Alliance
Upland and Disturbed Areas
San Timoteo Creek Riparian Plant Communities
City of Beaumont AMMP
Figure 4-5m

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
The current average width of the San Timoteo Creek Riparian Zone within the Study Area is approximately 79 meters. Descriptions of the riparian plant communities mapped within the San Timoteo Creek portion of the Study Area are provided below from the CNPS online edition (2024) of the "Manual of California Vegetation."6
Baccharis salicifolia Shrubland Alliance (Mulefat Alliance) This habitat alliance is dominated or co -dominated by mulefat in the shrub canopy with Artemisia californica, Baccharis emoryi, Baccharis pilularis, Malosma laurina, Nicotiana glauca, Pluchea sericea, Rubus spp., Salix exigua, Salix lasiolepis, Sambucus nigra and Tamarix spp. Emergent trees may be present at low cover, including Pinus sabiniana, Platanus racemosa, Populus fremontii, Quercus spp. or Salix spp.

Mulefat alliance riparian habitat consists of a continuous shrub canopy that is less than 5 meters in height and has a sparse herbaceous layer. It is typical of canyon bottoms, floodplains, irrigation ditches, lake margins, and stream channels. Approximately 10.27 acres of mulefat alliance riparian habitat exists within the San Timoteo Creek portion of the Study Area.

Populus fremontii — Baccharis salicifolia Association (Fremont Cottonwood / Mulefat Association) This habitat association has a simple tree canopy dominated by Fremont cottonwood, with an intermittent to open shrub layer dominated by mulefat, and a variable herbaceous layer. The canopy height is less than 25 meters. Fremont cottonwood / mulefat association riparian habitat is typical of floodplains, along low -gradient rivers, perennial or seasonally intermittent streams, springs, in lower canyons in desert mountains, in alluvial fans, and in valleys with a dependable subsurface water supply that varies considerably during the year. Approximately 50.36 acres of Fremont cottonwood / mulefat association riparian habitat exists within the San Timoteo Creek portion of the Study Area.

Populus fremontii — Salix (laevigata, lasiolepis, lucida ssp. lasiandra) Association (Fremont Cottonwood / Willow spp. Association)
This habitat association has a mixed tree canopy co -dominated by Fremont cottonwood and one or more of red willow, arroyo willow, and Pacific willow, with an intermittent to open shrub layer, and a variable herbaceous layer. The canopy height is less than 25 meters. Fremont cottonwood / willow spp. association riparian habitat is typical of floodplains, along low -gradient rivers, perennial or seasonally intermittent streams, springs, in lower canyons in desert mountains, in alluvial fans, and in valleys with a dependable subsurface water supply that varies considerably during the year. 6 https://vegetation.cnps.org/
WEST YOST 69

Page 2176 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

5.0 HISTORICAL RIPARIAN HABITAT HEALTH (NDVI)
The following subsections describe the historical characterization of riparian habitat health utilizing remote sensing data and the normalized difference vegetation index (NDVI), including methods and results.

5.1 Overview of NDVI Analysis
NDVI, a metric derived from remote sensing measurements by Landsat Program satellites, is used to assess the extent and quality of the riparian vegetation in the Study Area over a long-term historical period. NDVI is a commonly used numerical indicator of vegetation health that can be calculated from satellite remote -sensing measurements (Ke et al., 2015; Xue, J. and Su, B., 2017). NDVI is calculated from visible and near -infrared radiation reflected by vegetation and is an index of "greenness" correlated with photosynthesis that can be used to assess spatial and temporal changes in the distribution and productivity of vegetation (Pettorelli, 2013). Areas where the NDVI is higher have greener (e.g. healthier) vegetation than areas where NDVI is lower, allowing for spatial analysis of overall vegetation health over large areas. NDVI estimates range between -1.0 and 1.0. Negative NDVI estimates correspond to standing water, and low positive values (0 to 0.1) correspond to non -vegetated areas, such as barren rock and sand, snow, and water. NDVI estimates ranging from 0.1 to 1.0 correspond to vegetated areas, with very low - end estimates indicating sparse, unhealthy, or dormant vegetation, and increasing estimates towards 0.9 indicating higher amounts of dense, healthy green vegetation.

Although NDVI does not provide species -specific vegetation information, the regional scale of NDVI makes it an appropriate "first indicator" of regional changes in the extent and quality of riparian vegetation.

Remote sensing data to calculate NDVI are available for the entire extent of the Study Area from the early 1980s to present, which allow for a robust, long-term characterization of the spatial extent and quality of the riparian vegetation prior to the implementation of the start of the AMMP. The Landsat remote sensing data is freely available and can be used on an ongoing basis to continue to track NDVI trends over time and will be an important tool in the AMMP.

A limitation of NDVI data is that it is a composite view of plant species diversity, form, structure, density, and vigor. As such, changes in NDVI may be the result of any number of factors that impact the extent of riparian habitat (Markon et al., 1995; Markon and Peterson, 2002). In other words, NDVI does not provide a complete picture of how and why vegetative changes are occurring; it simply indicates a change in vegetation health. The changes need to be ground-truthed using other types of monitoring. Appendix C provides background information on NDVI, further explains why NDVI was chosen as an analytical tool for the development and on -going monitoring of the AMMP, discusses additional advantages and limitations of NDVI, and describes how NDVI estimates were used for the Study Area.

NDVI estimates were collected from the United States Geological Survey (USGS) using the Earth Resources Observation and Science (EROS) Center Science Processing Architecture (CSPA) On Demand Interface' (USGS, 2017b) for the period of March 1984 through October 2023. Of importance to this type of analysis are the satellite date for the entire annual vegetation growing -season of March to October. To obtain complete spatial coverage of the Study Area, NDVI estimates were requested for all Landsat scenes for Path 040, Rows 036 and 037 from the Landsat 4, 5, 7, Landsat 8, and Landsat 9 satellites. The NDVI were processed and uploaded to a centralized relational database, HydroDaVESM, which includes tools to

ESPA USGS
WEST YOST 70

Page 2177 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
manage, review, and extract NDVI estimates. The frequency of NDVI estimates from the Landsat 4, 5, 7, 8 and 9 satellites is every one to eight days. However, not all NDVI estimates are useable due to disturbances that can be caused by cloud cover, unfavorable atmospheric conditions, or satellite equipment malfunction. NDVI estimates were reviewed for these disturbances and any estimates determined erroneous due to these disturbances were excluded from analysis. Appendix C describes how the NDVI estimates were collected, reviewed, and assembled for the characterization of historical riparian health for this Report.

5.2 Overview of Riparian Zone, Study Segments, and Focus Areas To evaluate the health of the riparian habitat, a Riparian Zone, Segments, and Focus Areas were established for the extent of the Study Area. A "Riparian Zone" was delineated within the Study Area along the Cooper's and San Timoteo Creeks by drawing a polygon around the tree line. Next the Riparian Zone was divided into smaller sections called "Segments". Segments were generally established to be comparable in length and to capture changes or inputs to the hydrologic system. A total of three segments were generated— Cooper's Creek 1, San Timoteo 1, and San Timoteo 2. Next, "Focus Areas" were established based on the following criteria:
• Generally distributed evenly throughout the Segment; and/or • Co -located with surface or groundwater monitoring locations; and/or • Placed in areas where changes to the system are presumed (such as upstream or downstream from the discharge point of a WWTP).

Figure 5-1 shows the Riparian Zone, Segments, and Focus areas analyzed for this study. A total of 10 Focus Areas were generated—FA01 through FA10. Six Focus Areas were established within Cooper's Creek 1 Segment, and two each within the San Timoteo 1 and 2 Segments, respectively. Figures 5-2, 5-3, and 5-4 show the placement of the Focus Areas for each Segment. The Focus Areas are described further below:

Cooper's Creek 1 Segment:
• FA01 —upstream of the Beaumont WWTP discharge point
• FA02 — a second location upstream of the Beaumont WWTP discharge point • FA03 —directly downstream of the Beaumont WWTP discharge point • FA04 —adjacent to a groundwater monitoring site where depth to water measurements are available
• FA05 —just upstream of a culvert that appears to constrict flow and supports habitat health • FA06 —just downstream of the confluence with San Timoteo Creek.

San Timoteo 1 Segment:
• FA07 —the upstream end of the Segment and near groundwater monitoring sites where depth to water measurements are available
• FA08 —the downstream end of the Segment and near groundwater monitoring sites location where depth to water measurements are available
WEST YOST 71

Page 2178 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
San Timoteo 2 Segment:
• FA09 —the upstream end of the Segment and near surface water and groundwater monitoring sites
• FA10 —the downstream end of the Segment near the YVWD discharge point, and groundwater and surface water monitoring sites.

NDVI data was then extracted for each Segment and Focus Area and evaluated as described in Appendix C.

The following subsections describe the results of the NDVI data analysis.

5.3 Temporal Analysis of NDVI
NDVI pixels' within defined areas throughout the Study Area were analyzed for temporal trends in NDVI estimates via creation of time -series charts for the entire historical record of 1984 to 2023. The defined areas include riparian habitat areas of three Segments (large areas) and ten Focus Areas (small areas) as shown on Figures 5-1, 5-2, 5-3, and 5-4 and described in Section 5.2. The time series charts are used to characterize long- and short-term changes in NDVI in specific areas and provide context for interpreting the observed trends and changes in riparian habitat health.

Figures 5-5a, 5-6a, and 5-7a are time -series charts from 1984 to 2023 of the spatial average NDVI for pixels within the three large Segments: Cooper's Creek 1 Segment (0.16 mil— 5,759 NDVI pixels), San Timoteo 1 Segment (0.18 miZ — 4,573 NDVI pixels), and San Timoteo 2 Segment (0.15 mil- 3,093 NDVI pixels). Also shown in the figures is an NDVI map of riparian extent and health as of 2023. Figures 5-5a, 5-6a, and 5-7a show two datasets that illustrate trends in the NDVI estimates:

Spatial Average NDVI (green dots)
• The "Spatial Average NDVI" represents the average NDVI estimate of all NDVI pixels within the entire defined area (e.g. the Segment) for each day/date (e.g. 10/15/2023) of the available remote sensing data. These data provide a snapshot of the riparian habitat health for each day and can thus be used to characterize seasonal and long-term trends in NDVI for each defined area. The charts illustrate that the Spatial Average NDVI exhibits an oscillatory pattern caused by seasonal changes in the riparian habitat. This NDVI time -series pattern is typical for a deciduous forest, where NDVI values are higher in the growing season from March through October and lower in the dormant season from November through February.

Average Growing -Season NDVI (black dots and black curve) • The "Average Growing -Season NDVI" represents the annual average of all Spatial Average NDVI estimates within the growing season from March through October each year. This curve illustrates year-to-year changes in NDVI and can be used to assess long-term trends for the riparian habitat.

Figures 5-5b, 5-6b, and 5-7b are time -series charts for 1984 to 2023 of the Average Growing -Season NDVI (points and curve) for each of the smaller defined Focus Areas within the Cooper's Creek 1 Segment, San Timoteo 1 Segment, and San Timoteo 2 Segment, respectively. Each Focus Area is represented by one NDVI pixel. These Focus Areas compare short- and long-term trends in NDVI on a smaller spatial scale at $ Each NDVI pixel is 30 x 30 meters.

WEST YOST 72

Page 2179 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
strategically locations within the larger Segment areas related to monitoring points, discharge points, or points where changes in 'inputs' to the system occur, such as confluences of creeks.

To statistically characterize long-term trends in NDVI, the Mann -Kendall statistical trend test (Mann -Kendall test) was performed on the Average Growing -Season NDVI for all defined areas over the following three periods:
• 1984 to 2023: the entire period of record.
• 1984 to 2003: period of historically lower discharges from the Beaumont WWTP prior to an increase in Beaumont WTTP discharges that occurred at an increased rate starting in 2004 (trends in Beaumont WTTP discharges are described in more detail in Section 6.1). • 2004 to 2023: period of increased Beaumont WWTP discharges from the period prior to 2004 (1984 to 2003).

The Mann -Kendall test utilizes a ranking formula to analyze if there is a statistically significant trend (e.g. increasing trend, decreasing trend, or no trend) in the NDVI time -series. Appendix D describes the Mann -Kendall test methods and results. The Mann -Kendall test result for each Segment and Focus Area is shown on each time -series chart and summarized in Table 5-1.

Table 5-1.

Mann -Kendall Test
for Defined Areas
Results of the Average
in the Cooper's and
-Growing Season NDVI
San Timoteo Creeks
Trends
Defined Area
Figure
Number
Mann
Kendal Test Result
a)
Post
Increased Discharge
2004 to 2023
Period of Record
1984 to 2023
Prior to
Increased Discharge
1984 to 2003
Cooper's Creek 1
5-5a
Increasing
Increasing
Increasing
FA01
5-5b
Increasing
Increasing
Increasing
FA02
5-5b
Increasing
No Trend
Increasing
FA03
5-5b
Increasing
Increasing
Increasing
FA04
5-5b
Increasing
No Trend
Increasing
FA05
5-5b
Increasing
No Trend
Increasing
FA06
5-5b
Increasing
No Trend
Increasing
San Timoteo 1
5-6a
Increasing
No Trend
Increasing
FA07
5-6b
Increasing
No Trend
Increasing
FA08
5-6b
Increasing
Increasing
No Trend
San Timoteo 2
5-7a
No Trend
No Trend
Increasing
FA09
5-7b
Increasing
Decreasing
Increasing
FA10
5-7b
Increasing
Increasing
No Trend
(a) See Appendix D for a description of the Mann -Kendall statistical trend test and results.

Table 5-2 summarizes the Average Growing -Season NDVI for 1984, 2004, and 2023 and the change in NDVI from 1984 to 2003, 2004 to 2023, and 1984 to 2023. Table 5-2 also shows the maximum year -over -year change to the Average Growing -Season NDVI for the historical period.

WEST YOST
73

Page 2180 of 2775 ends

City of Beaumont
May 2025

Table 5-2. Characterization of Variability in the Average -Growing Season NDVI for Defined Areas in the Study Area Defined Area
Figure
Number
Average Growing Season NDVI
Difference in
Average NDVI
from 1984-2004
Difference in
Average NDVI
from 2004-2023
Difference in
Average NDVI
from 1984-2023
Maximum
Change in NDVI in
Any Given Year
1984
2004
2023
Cooper's Creek 1
5-5a

0.35 0.37

0.14 0.03

0.14 0.17

0.09 FA01
5-5b

0.37 0.42

0.22 0.04

0.22 0.26

0.11 FA02
5-5b

0.32 0.28

0.17 -0.03

0.17 0.14

0.15 FA03
5-5b

0.22 0.24

0.39 0.02

0.39 0.41

0.15 FA04
5-5b

0.32 0.32

0.23 -0.01

0.23 0.23

0.09 FA05
5-5b

0.57 0.64

0.13 0.07

0.13 0.19

0.13 FA06
5-5b

0.16 0.27

0.20 0.11

0.20 0.30

0.15 San Timoteo 1
5-6a

0.42 0.43

0.15 0.01

0.15 0.16

0.09 FA07
5-6b

0.59 0.54

0.16 -0.05

0.16 0.11

0.15 FA08
5-6b

0.53 0.62

0.07 0.10

0.07 0.16

0.11 San Timoteo 2
5-7a

0.40 0.36

0.16 -0.04

0.16 0.12

0.15 FA09
5-7b

0.53 0.40

0.30 -0.14

0.30 0.17

0.13 FA10
5-7b

0.51 0.49

0.13 -0.01

0.13 0.11

0.25 WEST YOST

Page 2181 of 2775 ends

City of Beaumont
AMMP
Last Revised: 01-09-2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
The data and results summarized in Tables 5-1 and 5-2 will be used for the analysis of NDVI by Segment in the following subsections.

5.3.1 Cooper's Creek 1 Segment and Focused Areas (FA01 to FA06) The Beaumont WWTP discharges within the upstream area of the Cooper's Creek 1 Segment and is the Segment most directly impacted by the discharge. There are two Focus Areas upstream of DP001 (FA01 and FA02) and four downstream (FA03 to FA06), with FA03 being directly downstream of DP001.

Figure 5-5a and Tables 5-1 and 5-2 show that for this Segment:
• The Average Growing -Season NDVI ranged from 0.35 to 0.52 and varied from year-to-year by no more than 0.09.
• The Average Growing -Season NDVI increased by 0.17 over the entire period of record (entire period), increased by 0.03 for the period prior to increased discharge at the Beaumont WTTP (1984 to 2003), and increased by 0.14 for the period of increased discharge at the Beaumont WTTP (2004 to 2023).
• The Mann -Kendall test of the Average Growing -Season NDVI indicates an "increasing trend" over the entire period, 1984 to 2003, and 2004 to 2023.

Figure 5-5b and Tables 5-1 and 5-2 show that for the six Focus Areas:
• The Average Growing -Season NDVI ranged from 0.16 to 0.78 and varied from year-to-year by no more than 0.15.
• For all six Focus Areas, the Mann -Kendall test result on the Average Growing -Season NDVI indicates:
an "increasing trend" for the entire period,
an "increasing trend" or "no trend" for 1984 to 2003,
and an "increasing trend" for 2004 to 2023
• For the entire period, the Average Growing -Season NDVI increased at all Focus Areas, with the highest increase of 0.41 occurring at FA03, which is located immediately downstream of Beaumont WWTP DP001.
• For 1984 to 2003:
the Average Growing -Season NDVI decreased at two of the Focus Areas by 0.01 and 0.03 (FA04 and FA02),
— and increased at four of the Focus Areas by 0.04, 0.02, 0.07, and 0.11 (FA01, FA03, FA05, and FA06).
• For 2004 to 2023, the Average Growing -Season NDVI increased at all of the Focus Areas.

The highest increase is 0.39 at FA03 just downstream of Beaumont WWTP effluent discharge outfall.
• The NDVI for FA05 exhibits different values and historical trends than the other Focus Areas along Cooper's Creek. For the 1984 to 2003 period, the Average Growing -Season NDVI for FA05 are much higher than the other Focus Areas (between about 0.4 to 0.2 higher). For the 2004 to 2023 period correlating with increased discharge from the Beaumont WWTP, FA05 does not show an increasing trend in NDVI until the later years (2019-2023), while the other Focus Areas exhibit a progressively increasing trend in NDVI from 2004-2023. However, WEST YOST 75

Page 2182 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
since 2004 NDVI for the other Focus Areas are still generally below FA05, except for FA03 located immediately downstream of Beaumont WWTP DP001. This suggests that there may be a different factor, other than surface water discharge, supporting the riparian vegetation at FA05.

These trends observed at the six Focused Areas are comparable to the trends observed for the entire Cooper's Creek 1 Segment.

5.3.2 San Timoteo 1 Segment and Focused Areas (FA07 and FA08).

The San Timoteo 1 Segment is downstream of Cooper's Creek 1 Segment and just downstream of the confluence between Cooper's and San Timoteo Creeks. There are two Focus Areas sited in proximity to groundwater monitoring sites where water level measurements are available. Figure 5-6a and Tables 5-1 and 5-2 show that for this Segment:
• The Average Growing -Season NDVI ranged between 0.47 and 0.58 and varied from year-to-year by no more than 0.09.
• The Average Growing -Season NDVI increased by 0.16 over the entire period, increased by

0.01 for 1984 to 2003, and increased by 0.15 for 2004 to 2023. • The Mann -Kendall test of the Average Growing Season NDVI indicates an "increasing trend" over the entire period and 2004 to 2023, and "no trend" over 1984 to 2003.

Figure 5-6b and Tables 5-1 and 5-2 show that for the two Focus Areas:
• The Average Growing -Season NDVI ranged between 0.46 and 0.74 and varied from year-to-year by no more than 0.15.
• The Mann -Kendall test result on the Average Growing -Season NDVI indicates:
an "increasing trend" for the entire period,
an "increasing trend" and "no trend" for 1984 to 2003,
and an "increasing trend" and "no trend" for 2004 to 2023. • For the entire period, the Average Growing -Season NDVI increased by 0.11 at FA07 and by

0.16 at FA08.
• For 1984 to 2003, the Average Growing -Season NDVI decreased by 0.05 at FA07 and increased by 0.10 at FA08.
• For 2004 to 2023, the Average Growing -Season NDVI increased by 0.16 at FA07 and increased by 0.07 at FA08.
• These trends observed in the two Focused Areas are comparable to the trends observed for the entire reach of San Timoteo Creek 1.

WEST YOST 76

Page 2183 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

5.3.3 San Timoteo 2 Segment and Focused Areas (FA09 and FA10) The San Timoteo 2 Segment is downstream of the San Timoteo 1 Segment and just upstream of the YVWD Henry N. Wochholz DP001. There are two Focus Areas sited in proximity to groundwater monitoring sites where water level measurements are available. Figure 5-7a and Tables 5-1 and 5-2 show that for this Segment:
• The Average Growing -Season NDVI ranged between 0.31 and 0.52 and varied from year-to-year by no more than 0.15.
• The Average Growing -Season NDVI increased by 0.12 for the entire period, decreased by

0.04 for 1984 to 2003, and increased by 0.16 for 2004 to 2023. • The Mann -Kendall test result on the Average Growing -Season NDVI indicates an "increasing trend" for 2004 to 2023, and "no trend" for 1984 to 2003 and the entire period.

Figure 5-7b is a NDVI time -series chart for 1984 to 2023 of the Average Growing -Season NDVI for one NDVI pixel for each of the two Focus Areas within the San Timoteo 2 Segment, called FA09 and FA10. Figure 5-7b and Tables 5-1 and 5-2 show that:
• The Average Growing -Season NDV► ranged between 0.30 and 0.70 and varied from year-to-year by no more than 0.25.
• The Mann -Kendall test result on the Average Growing -Season NDVI indicates:
an "increasing trend" for the entire period,
an "increasing trend" and "decreasing trend" for 1984 to 2003, and an "increasing trend" and "no trend" for 2004 to 2023. • For the entire period, the Average Growing -Season NDVI increased by 0.17 at FA09 and by

0.11 at FA10.
• For 1984 to 2003, the Average Growing -Season NDVI decreased by 0.14 at FA09 and decreased by 0.01 at FA10.
• For 2004 to 2023, the Average Growing -Season NDVI increased by 0.30 at FA09 and increased by 0.13 at FA10.
• These trends observed in the two Focused Areas are comparable to the trends observed for the entire reach of San Timoteo Creek 2.

5.3.4 Conclusions from Temporal Analysis
• The Average Growing -Season NDVI observed amongst all the defined Segments and Focus Areas ranges between 0.16 to 0.78, with the largest range along the Cooper's Creek 1 Segment and Focus Areas.
• Over the entire period, the Average Growing -Season NDVI increased at all Segments and Focus Areas across the Study Area, indicating an overall increase in the riparian habitat health over the historical period. The Mann -Kendall test results corroborate the Average Growing -Season NDVI trends indicating an "increasing trend" at all the Segments and Focus Areas for the entire period, expect for the San Timoteo 2 Segment where there was "no trend".

WEST YOST 77

Page 2184 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
• Over the entire period, the Average Growing -Season NDVI increased at all Segments and Focus Areas across the Study Area, indicating an overall increase in the riparian habitat health over the period of increased discharge at the Beaumont WWTP. The Mann -Kendall test results corroborate the Average Growing -Season NDVI trends indicating an "increasing trend" at all the Segments and Focus Areas for 2004 to 2023 expect at FA08 and FA09 where there was "no trend".
• The significantly larger increases in NDVI (> 0.20) observed for the 2004 to 2023 period in the Study Area are:

0.22 at FA01, the Focus Area most upstream of the Beaumont WWTP discharge along Cooper's Creek 1 Segment.

0.39 at FA03, the Focus Area located immediately downstream of Beaumont WWTP discharge along Cooper's Creek 1 Segment.

0.23 at FA04, the next Focus Area located downstream of Beaumont WWTP discharge along Cooper's Creek 1 Segment.

0.30 at FA09, which is the upstream Focus Area along the San Timoteo 2 Segment.

WEST YOST 78

Page 2185 of 2775 ends

City of Beaumont
May 2025

eaumont AMMP\GIS
Prepared by:

WEST I YOST
0 2
0 Miles
Km
2Page 2186 of 2775
Prepared for:

City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
Cooper's Creek 1 Segment
San Timoteo 1 Segment
San Timoteo 2 Segment
Study Area
❑ Focus Areas
• WWTP Discharge Point
- - Streams
Notes:

1. Riparian Zone was drawn using tree line.

2. Study Segments are sections of the riparian corridor that will be studied on a larger scale using the NDVI dataset.

3. Focus Areas are spaced approximately 11,000 feet along the extent of the study area as well as before and after important features such as waste discharge points and stream confluences.

4. Focus Areas are defined as a one pixel area
(30 meters x 30 meters) of NDVI data.

5. WWTP - wastewater treatment plant
Riparian Zone, Study Segments, and
Focus Areas
City of Beaumont AMMP
Figure 5-1

Prepared by:

Prepared for:

WEST I YOST
0 1
Miles City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
0 1,000
Feet
2°°Page 2187 of 2775
Riparian Zone and Study Segments
ICooper's Creek 1
Focus Areas
O WWTP Discharge Point
Beaumont WWTP Boundary
Notes:

1. Riparian Zone was drawn using tree line.

2. Study Segments are sections of the riparian corridor that will be studied on a larger scale using the NDVI dataset.

3. Focus Areas are spaced approximately 11,000 feet along the extent of the study area as well as before and after important features such as waste discharge points and stream confluences.

4. Focus Areas are defined as a one pixel area
(30 meters x 30 meters) of NDVI data.

5. WWTP - wastewater treatment plant
Henry N
Yuc1I
Wochholz
RWRF DP 001
Riparian Zoneie
Badlands
Beaumont
WWTP DP 001
Bp,iumont
Focus Areas FA01, FA02, FA03, FA04, and FA05
for NDVI Analysis
City of Beaumont AMMP
Figure 5-2

Prepared by:

Prepared for:

WEST I YOST
°
1 Miles City of Beaumont
Adaptive Management and
Mitigation Plan (AMMP) BEAUMONT
°
1,000
Feet
Z'°°Page 2188 of 2775
Riparian Zone and Study Segments
Cooper's Creek 1
San Timoteo 1
Focus Areas
Notes:

1. Riparian Zone was drawn using tree line.

2. Study Segments are sections of the riparian corridor that will be studied on a larger scale using the NDVI dataset.

3. Focus Areas are spaced approximately 11,000 feet along the extent of the study area as well as before and after important features such as waste discharge points and stream confluences.

4. Focus Areas are defined as a one pixel area
(30 meters x 30 meters) of NDVI data.

5. WWTP - wastewater treatment plant
Henry N
Wochholz Yucaipa
RWRF DP 001
Riparian Zone
Badlands
Beaumont
WWTP DP 001
Gr_�uisu,rn
Focus Areas FA06, FA07, and FA08
for NDVI Data Analysis
City of Beaumont AMMP
Figure 5-3

0 1,200
2,400
Prepared by:

WEST I YOST
Scale in Feet

Page 2189 of 2775 ends

Prepared for:

City of Beaumont
Adaptive Management and '
Mitigation Plan (AMMP)
Riparian Zone and Study Segments
San Timoteo 1
San Timoteo 2
Focus Areas
0 WWTP Discharge Point
Notes:

1. Riparian Zone was drawn using tree line.

2. Study Segments are sections of the riparian corridor that will be studied on a larger scale using the NDVI dataset.

3. Focus Areas are spaced approximately 11,000 feet along the extent of the study area as well as before and after important features such as waste discharge points and stream confluences.

4. Focus Areas are defined as a one pixel area
(30 meters x 30 meters) of NDVI data.

5. WWTP - wastewater treatment plant
C��linu's:1
Henry N
Wochholz
RWRF DP 001
Riparian Zone
The
Badlands
of
0 L
„Yoh Ra
329r
Beaumont
WWTP DP 001 1G ,a urn ont
Focus Areas FA09 and FA10
for NDVI Data Analysis
City of Beaumont AMMP
Figure 5-4

2023 Maximum Growing -Season NDVI
September 23, 2023
■ > -land≤ 0
> 0 and ≤ 0.1
>0.1and ≤ 0.2
> 0.2 and ≤ 0.3
> O.3 and ≤ 0.4
> 0.4 and ≤ 0.5
▪ >0.5and ≤ 0.6
■ >0.6and ≤ 0.7
■ >0.7and ≤ 1
nCooper's Creek 1
W/

WEST / YOST
Water. Engineered.

NDVI

0.9 —

0.8 —

0.7 —

0.6 —
-
Z 0.5 —

0.4 —

0.3 —

0.2 —

0.1 —
r
NDVI Legend
• Spatial Average NDVI for 0.16 -Square Mile Area (5,759 pixels) Growing Season (March -October)
• Average NDVI During the Growing Season
i
•
•
i
66 •
i
•
•
"se6b a
m ® ®o
•
•c
1984 -2003 - Period pr
•
•
•
or to 20
•
S di 4%::•:•
%•
••
04 it
e
•
crease in disch
(II
1984
arge
•
fr
om E
P •
•
•
• to
•
•
•
•
00 A
1 •
. A.
16 s
• • 111
•
• ® • S ••
• ® •
il• • •
•
•
•
eaumont WWTP - MK Test: Increasing
1 •
'• ••-•
Illg II
ecor
1984 -2023 - Entire Period of R
• •
• ••
•
•
1 1
1 Miles A
1 •

1. • i
-yir
• •• •
••
•
1 •
•
•
••
IF •
•
•
•
•
• • •
M
Cooper's Creek 1 Segment
t
1 ••
• •••
• •• ••
•
•
•
••
•
i
•
•
•
•
el •Z
• •
•
Beaumont_. -'
• e•
•• • •
• •
• _
2004 -2023 - Period after increase in discharge from Beaumont WWTP - MK Test: Increasing - MK Test: Increasin
g
2022
2024
.Beaumont
WWTP DP 001
i
••
1986
Author: AK
Date: 20241212
File: Figure 5-5a_NDVI_StudyArea-A.grf
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
- 0.9
- 0.8
- 0.7
- 0.6
- 0.5 z
Time Series of NDVI for Cooper's Creek 1 Segment
City of Beaumont AMMP

Page 2190 of 2775 ends

Figure 5-5a

0.9 —

0.8 —

0.7 —

0.6 -
> -
0 z 0.5 —

0.4 —

0.3 —

0.2 —

0.1 —
Average Value for Growing Season at 30m x 30m (1 Pixel) Area (Mann -Kendall Trend Result for 1984-2023; 1984-2003; 2004-2023) FA01 (increasing; increasing; increasing) 0 FA04 (increasing; no trend; increasing) FA02 (increasing; no trend; increasing) FA05 (increasing; no trend; increasing) FA03 (increasing; increasing; increasing) • FA06 (increasing; no trend; increasing) ef
1984
va
1986
1988
1990
1992
1994
1996

WEST I YOST
Water. Engineered.
0„
rl
�v 71
o
Author: AK
Date: 20241216
File: Figure 5-5b_NDVI_5tudyArea-A-sm areas.grf
r
i
ii
San Timoteo
GMZ •
_...Beumont
WWTP DP001
Cooper's Creek 1 Segment
Growing Season (March -October)
—�— Average Value for Growing Season Cooper's Creek 1
1 , ,.__ _
,,,,
----,,
„„__ _._ !ii --.-
1 .,.., PI _. _
_ _
__._ _._

7._ _el.__
.. ._
,._. .____ -IL
-/ _47-.-1)----e-----.---.-- 'li
71 to --7--
----- AL 7:
-0, 4
__.___..„
19 _.,
Is ii i ill
9 _.„
J
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
2022
— 0.9
— 0.8
— 0.7
— 0.6
- >
0 — 0.5 z
— 0.4
— 0.3
— 0.2
— 0.1
2024
Time Series of NDVI for Focus Areas along Cooper's Creek 1 City of Beaumont AMMP

Page 2191 of 2775 ends

Figure 5-5b

NDVI
■ >-land≤ 0
> 0 and ≤ 0.1
> 0.1 and ≤ 0.2
>0.2and≤ 0.3
> 0.3 and ≤ 0.4
> 0.4 and ≤ 0.5
>0.5and≤ 0.6
>0.6and≤ 0.7
>0.7and≤ 1
San Timoteo 1
w

WEST I YOST
Water. Engineered.

0.9 —

0.8 —

0.7 —

0.6 —
0 0.5 —
z

0.4 —

0.3 —

0.2 —

0.1 —
•
•
•
•
r
r
NDVI Legend
Spatial Average NDVI for 0.18 -Square Mile Area (4,573 pixels) Growing Season (March -October)
Average NDVI During the Growing Season
•41
•
•
a
•
•
•
f
lIr
•
•
•
•
•
•

O• • • •{
• II
ti •
•
•
1984 -2003 - Period prior to 2004 increase in discharge from B •
•
a
•
•
•
•
•
•
• • • • I
• •
aw
I I
■
•
•
•
•
•
•
0 •
i
•
eaumont WWTP - MK Test: No trend
•
•
•
•
•
•
•
19£
1 4-
4 -2023 - Entire Period of Record - MK Test: Increasin
Obi
i
a
• •
•
•
•
•
2 •
•
•
/liar liblV•
•
•
004 -
•
• •
2023 - Period
•
after
i
0 •
•
a
increase in dis
•
•
San Timoteo
GMZ
San Timoteo 1 Segment
•
•
e
• • • • •
• •
•
•
a •
1 ■
:harg
•
e
•
from
•
•
• •
•
•
I
Beaumont WWTP -
•
•
•
•
r
OK T
•

0.9 0.8

0.7 • — 0.6

4.-
_ • • ;4 , O - 0.5
•
•
•
•
•
est: Increasin
g
••
••
2022
1984
1986
Author: AK
Date: 20241212
File: Figure 5-6a_NDVI_StudyArea-B.grf
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
— 0.4
— 0.3
— 0.2
— 0.1
2024
z
Time Series of NDVI for San Timoteo 1 Segment
City of Beaumont AMMP

Page 2192 of 2775 ends

Figure 5-6a

0.9 -

0.8 -

0.7 -

0.6 -
> -
O
z 0.5 —

0.4 —

0.3 —

0.2 —

0.1 —
Average Value for Growing Season at 30m x 30m (1 Pixel) Area (Mann -Kendall Trend Result for 1984-2023; 1984-2003; 2004-2023) } FA07 (increasing; no trend; increasing) —0— FA08 (increasing; increasing; no trend) —0-
i
i
N\
1 •
San Timoteo
GMZ
YucaipaCreek
Henry N. Wochholz
-.r
! RWRF DP 001 L..`
San Timoteo 1 Segment
i
Beaumont l
WWTP DP 001
Coo/3er
i
Growing Season (March -October)
f Average Value for Growing Season San Timoteo 1
U
—ate
i
r
I
— 0.9
— 0.8
— 0.7
— 0.6
O
- 0.5 z
- 0.4
- 0.3
- 0.2
- 0.1
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024

WEST I YOST
Water. Engineered.

Author: AK
Date: 20241213
File: Figure 5-6b_NDVI_StudyArea-B-sm areas.grf
Time Series of NDVI for Focus Areas along San Timoteo 1 City of Beaumont AMMP

Page 2193 of 2775 ends

Figure 5-6b

N DVI
■
•
•
> -land≤ 0
> 0and≤ 0.1
>0.1and ≤ 0.2
>0.2and ≤ 0.3
>0.3and ≤ 0.4
>0.4and ≤ 0.5
>0.5and ≤ 0.6
>0.6and ≤ 0.7
>0.7and ≤ 1
II San Timoteo 2
N1/

WEST II YOST
Water. Engineered.

0.9 —

0.8 —

0.7 —

0.6 —
0 0.5 —
z

0.4 —

0.3 —

0.2 —

0.1 —
•
• °
1 r
NDVI Legend
• Spatial Average NDVI for 0.15 -Square Mile Area (3,093 pixels) Growing Season (March -October)
Average NDVI During the Growing Season
• 1111
•
•M
•
•• •
•
1984 -2003 - Per
•
•
•
—119
•
i
iod prio
•
•
r to
•
•
•
•
•
•
•
•
•
• •
••
•• •
•
004 increase i
disc
harge fr
om E
eaumont WW
TP - MK Test: No t
1 •
•o
•
•
•
•
iod of Record - MK Test: No trend
1 1984 -2023 - Enl
■
end
ire Pe
1 1
••~ •• •'
•
•
1 ••
•
004
1 •
•
o•
r Ai
•I ••
•
-2
1 023
•
•
- Period
•
after
San Timoteo
GMZ
- .._...._Yucaipa Ci-P
Henry N. Wochholz
o
r
i
San Timoteo 2 Segment
'Beaumont_..

GMZ
Coal er
•
•
..Beaumont
WWTP DP 001
�k^
it I
•
•
••
•
•
e
•
••
i •
• io
•
•
••
• • •
•
increase in discharge
fron
F
•
F
Beaum
•
•
•
S• •
•
•
•
•
ont WWTP - MK Test: Increasing
•
•
•
•
s
i

0.9 0.8

0.7 - 0.6
- 0.5
z
- 0.4
- 0.3
- 0.2
- 0.1
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 Author: AK
Date: 20241212
File: Figure 5-7a_NDVI_StudyArea-C.grf
Time Series of NDVI for San Timoteo 2 Segment
City of Beaumont AMMP

Page 2194 of 2775 ends

Figure 5-7a
r

0.9 —

0.8 —

0.7 —

0.6 —
> -
0 z 0.5 —

0.4 —

0.3 —

0.2 —

0.1 —
Average Value for Growing Season at 30m x 30m (1 Pixel) Area (Mann -Kendall Trend Result for 1984-2023; 1984-2003; 2004-2023) FA09 (increasing; increasing; increasing) f FA10 (increasing; increasing; increasing) a
L
—f—
L
—f—
i
IMr
i
—0--
L
i
1 San Timoteo
GMZ ,._..

YucaipaCrP — cic �`---.

Henry N. Wochholz
i'l ! RWRF DP 001

4.22 .o
i r'
San Timoteo 2 Segment
',Beaumont-..-
GMZ
i
WWTP DP 001
C°°p, er r,
Growing Season (March -October)
—•— Average Value for Growing Season San Timoteo 2
7i
— 0.9
— 0.8
— 0.7
— 0.6
— 0.5 z
— 0.4
— 0.3
— 0.2
— 0.1
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 NV
Time Series of NDVI for Focus Areas along San Timoteo 2 City of Beaumont AMMP
WEST i' YOST
Water. Engineered.

Author: AK
Date: 20241216
File: Figure 5-7b_NDVI_StudyArea-C-sm areas.grf

Page 2195 of 2775 ends

Figure 5-7b

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

6.0 HYDROLOGIC CHARACTERIZATION
This section describes the characterization of WWTP historical discharges, surface water flows, surface water quality, groundwater levels, and groundwater quality for the Study Area.

6.1 WWTP Discharges
The location of currently active and inactive WWTP discharge points within and adjacent to the Study Area are shown on Figure 2-1. Table 6-1 shows the total annual discharges (in acre-feet per year [afy]) for three WWTP discharge points that were active during the period of record shown from 1986 to 2023:
• Active — Beaumont WWTP DP001 and YVWD Henry N. Wochholz RWRF DP001 • Inactive — Beaumont WWTP DP007
Two active WWTP discharge points bracket the Study Area —Beaumont WWTP (DP001) at the upstream extent of the Study Area in Cooper's Creek, and the Henry N. Wolchholz RWRF DP001 at the downstream extent of Study Area on San Timoteo Creek (Figure 2-1). Figure 6-1 is a time series chart of the discharge for the two active WWTP discharge locations in the Study Area. The figure includes the annual total discharge in afy (afy, bars); the daily discharge in mgd, where available (light lines); and the 30 -day moving average discharge in mgd (bold lines). Generally, the discharges from the City and YVWD have increased over time and mirror the increase in population growth for the region:
• Beaumont WWTP DP001. Total annual discharges increased monotonically year-to-year from 19899 to 2003, from about 1,200 to 1,900 afy, a 55 percent increase over 15 years. In 2004, the rate of increase in the annual discharge increased. For the 17 year period from 2004 to 2020, discharges increased from about 2,000 afy to 4,300 afy in 2020, a 100 percent increase. In 2023, total discharge was 3,837af and daily discharge averaged about 3.3 mgd. • YWVD Henry N. Wochholz DP001. Annual discharges show a similar increasing trend as the Beaumont WWTP where discharge steadily increased from 1987 to 2003 from about 1,040 afy to 3,600 afy, a 60 percent increase over 15 years. For the 15 -year period from 2004 to 2018, discharges increased from about 3,900 afy to 4,500 afy, a 15 percent increase.

In 2023, total discharge was 3,783 of and daily discharge averaged about 3.7 mgd.

There were two historical Beaumont WWTP discharge locations, one located on Noble Creek (DP008) and the other on a tributary to Noble Creek (DP007). These locations are shown on Figure 2-1. The City has no record of discharging from DP008, and discharges at DP007 occurred between 2010 and 2014 averaging about 543 afy. As shown on Figure 6-1, there was a reduction in the annual discharge from DP001 during these five years when the DP007 was active.
9 Data is unavailable prior to 1989
WEST YOST 89

Page 2196 of 2775 ends

City of Beaumont
May 2025

Table 6-1. Historical
WWTP Discharges(')
Year
Beaumont
WWTP
YVWD WWTP(d)
DP -001,
afie'`i
DP -007,
of
Henry N. Wochholz,
af(e)
1987
--
--
1,041.21
1988
--
--
2,067.97
1989
1,232.30
--
2,269.41
1990
1,299.79
--
2,423.38
1991
1,292.81
--
2,516.70
1992
1,353.32
--
2,596.22
1993
1,370.77
--
2,615.18
1994
1,346.34
--
2,673.92
1995
1,403.36
--
2,579.31
1996
1,475.50
--
2,655.91
1997
1,517.39
--
2,793.39
1998
1,579.07
--
3,135.79
1999
1,593.03
--
3,142.05
2000
1,605.83
--
3,321.55
2001
1,601.18
--
3,349.26
2002
1,711.72
--
3,263.32
2003
1,909.54
--
3,600.21
2004
2,162.05
--
3,890.71
2005
2,427.36
--
3,896.05
2006
2,622.86
--
3,978.78
2007
2,910.04
--
4,106.08
2008
2,860.21
--
4,023.56
2009
2,869.93
--
4,010.18
2010
2,422.85
573.68
4,128.54
2011
2,371.03
660.18
4,224.75
2012
2,537.27
542.91
4,132.78
2013
2,628.21
518.11
4,200.43
2014
2,994.87
420.02
4,055.50
2015
3,356.84
--
3,363.70
2016
3,547.84
--
4,098.49
2017
3,663.22
--
4,201.71
2018
3,799.72
--
4,469.49
2019
4,103.63
--
4,072.07
2020
4,343.66
--
4,236.57
2021
3,839.48
--
4,149.02
2022
3,637.96
--
3,987.05
2023
3,836.55
--
3,783.25
Summary Statistics dill
Minimum
1,232.30 420.02
1,041.21
Mean
2,435.07 542.98
3,433.88
Maximum
4,343.66
660.18
4,469.49
(a) WWTP- Waste Water Treatment Facility
(b) of - acre-foot.
(c) From November 1, 2022, to January 31, 2023, the discharge data for Beaumont WWTP DP -001 was estimated based on October 2022 discharge. (d) Yucaipa Valley Water District
(e) Discharge is estimated for November 2023 using October 2023 discharge volumes.

WEST YOST

Page 2197 of 2775 ends

City of Beaumont
AMMP
Last Revised: 12-30-2024

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

6.2 Surface Water
The following subsections describe the historical surface water flows and quality for the Study Area.

6.2.1 Surface Water Flows
There are five surface water monitoring sites within and adjacent to the Study Area: CC -01, CC -03, STC-02, STC-01, and YVWD-A. Figure 6-2 shows the location of sites with the Study Area (and relative to the NDVI analysis Segments) and the available flow data from 2005 to 2023. The surface water flow measurements are collected bi-weekly for the Maximum Benefit Monitoring Program and the surface water flow measurements are grouped and plotted by Segment from upstream to downstream. The data show:
• Cooper's Creek 1 Segment — Two surface water monitoring stations (CC -01 and CC -03) are within this Segment and Cooper's Creek. Both stations are located downstream of the Beaumont WWTP DP001. An additional surface water monitoring station is located in the San Timoteo Creek and adjacent to the Cooper's Creek 1 Segment (STC-02); however, no streamflow has been observed at this station. Since 2005, surface water flows ranged from about 0 to 36 cubic feet per second (cfs). Flow in Cooper's Creek generally decreases downstream along the Segment between CC -01 and CC -03. Overall, the volume of surface water flows has increased since 2005, which is likely attributable to increased discharges from Beaumont WWTP DP001.
• San Timoteo 1 Segment — One surface water monitoring station (STC-01) is within this Segment. Since 2005, surface water flows ranged from about 0 to 51 cfs. Surface water flow at STC-01 is generally less than flow at the upstream CC -03 site. Overall, the volume of surface water flows increased at STC-01 since 2005, which could be attributable to increased discharges from Beaumont WWTP DP001.
• San Timoteo 2 Segment — One surface water monitoring station (YVWD-A) is within this Segment. Since 2005, surface water flows ranged from about 0 to 57 cfs. Surface water flow at YVWD-A is generally less than flow at the upstream STC-01 site. Overall, the volume of surface water flows increased at YVWD-A since 2005, which could be attributable to increased discharges from Beaumont WWTP DP001.

Overall, based on the available data, surface water flow generally decreases from upstream to downstream through the Study Area. Flows have increased over time at all sites. The increase in surface flows is likely due to increased discharges from Beaumont WWTP DP001. Both San Timoteo 1 and San Timoteo 2 Segments exhibit larger winter storm peak flows when compared to Cooper's Creek 1 Segment, and may be attributable to flashier flows originating in Noble and San Timoteo Creeks. There were very few instances of no -flow conditions throughout the Study Area over the period of record.

However, during drought periods (such as 2013 and 2014), there were instances of no -flow conditions in the creeks within the Study Area reaches, particularly in San Timoteo 1 and San Timoteo 2 Segments.

WEST YOST 91

Page 2198 of 2775 ends

City of Beaumont
May 2025

Beaumont WWTP DP -001
Discharge from Beaumont WWTP DP -001 (afy)
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0 6
— Beaumont WWTP DP -001 Discharge (Daily - mgd)
— 30 -Day Moving Average Beaumont WWTP DP -001 Effluent Discharge (mgd) Beaumont WWTP DP -001 Discharge (Annual - afy)
Daily Discharge (mgd)
NJ W A In
I I I !
! I I
i
1 I
1 i
i ll l1
lRk' t
llgIi
WHIM
-
I

I I I I I I I I
!1
I
i l l I l l I l l I l l
0 1 1 1 1 1 1 1 1 1 1 1
I I I iI
1 1 1 1 1 1 1 1 1 1 1 1
l i i i
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 Henry N Wochholz RWRF DP -001
4,500 —
O
U
O
T
CU
S
E
O
O
cu
Loo
u_
Q
4,000
3,500 —
3,000
2,500
2,000
1,500
1,000
500
0 IN
6 --
5 4
3 2—
,a

WEST I YOST
Water. Engineered.
— Henry N Wochholz RWRF DP -001 Discharge (Daily - mgd) — 30 -day Moving Average Henry N Wochholz RWRF DP -001 Effluent Discharge (mgd) El Henry N Wochholz RWRF DP -001 Discharge (Annual - afy) 1 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 Notes:

1. Waste Water Treatment Plant (WWTP)

2. Regional Water Recycling Facility (RWRF)

3. acre-foot per year (afy)

4. million gallons per day (mgd)

5. From November 1, 2022, to January 31, 2023, the discharge data for Beaumont WWTP DP -001 was estimated based on October 2022 discharge

6. From November 1, 2023, to November 30, 2023, the discharge data for Henry N Wochholz RWRF DP -001 was estimated based on October 2023 discharge

7. Henry N Wochholz RWRF DP -001 discharge was reported as a monthly averagetrnpdfiorn11690OQp fk2:7375 File: Figure 6-1_DailyEf laentoischarge_W WTP.grf
Daily Effluent Discharge to Cooper's Creek and San Timoteo Creek at Beaumont WWTP DP -001 and Henry N Wochholz RWRF DP -001 City of Beaumont AMMP
1986-2023
Figure 6-1

Cooper's Creek 1 Segment
60 55
50 45
40 35
30 o 25
`l 20
15 10
5 0
2005
2007
San Timoteo 1 Segment
60 55
50 45
40 35
4-
30 o 25
20 15
10 5
0 2005
2009
2011
2013
2015
2017
2019
2021
2023
2007
2009
2011
2013
San Timoteo 2 Segment
60 55
50 45
40 35
30 0 25
2015
2017
A v t
2019
2021
2023
20 =
15 10
5 0
2005

WESTIYOST
Water. Engineered.
—r'n .�,'�.✓�,r''�, ✓rte t ham' 1,�J"\AptyL
`w,
2007 2009 2011 2013 2015 2017 2019 2021 2023
Author: AK
Date: 20241212
File: Figure 6-2_SWL_3_Segments.grf
Upper Cooper's Creek 1 Segment
Surface Water Flow (cfs)'-2
CC -01
CC -03
San Timoteo 1 Segment
Surface Water Flow (cfs)1,2
STC-01
San Timoteo 2 Segment
Surface Water Flow (cfs)t-2
YVWD-A
YVWD-A
Henry N
Wochholz
RWRF
DP 001
San J;
STC-01
CTh
Cooper's Creek 1 Segment
San Timoteo 1 Segment
San Timoteo 2 Segment
Surface Water Station
Notes:

1. cfs = cubic feet per second

2. No surface water flow data for STC-02
Yucaipa Creek
STC-02
CC -03
CC -01
Coop
Beaumont C)=eek
WWTP DP 001
0 0.5 1
I I
2 Miles
A
Surface Water Flows at Select
Surface Water Monitoring Locations
City of Beaumont AMMP

Page 2200 of 2775 ends

Figure 6-2

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

6.2.2 Surface Water Quality
Surface water quality data is collected at the same five surface water sites in the Study Area (CC -01, CC -03, STC-02, STC-01, and YVWD-A) as part of the Maximum Benefit Monitoring Program and is generally available since 2003. Surface water samples are collected bi-weekly, when flows are present. Figures 6-3 and 6-4 show the time history of nitrate (as -nitrogen) and total dissolved solids (TDS) concentrations for each surface water site, and the two active WWTP discharges. The surface water quality data are plotted by NDVI analysis Segment from upstream to downstream in the Study Area.

6.2.2.1 Nitrate as Nitrogen
Review of the surface water nitrate data shown in Figure 6-3 indicates the following for each Study Area Segment:
• Cooper's Creek 1 Segment — Overall, the nitrate concentration at CC -01 and CC -03 mimic the concentrations of the discharge from Beaumont WWTP DP001. The Beaumont WWTP concentrations range from non -detect to 18 mg/L and have a long-term average of

4.2 mg/L. Nitrate concentrations at CC -01 and CC -03 are generally less than the WWTP concentrations and have a long-term average of 2.8 and 3.0 mg/L, respectively. There appears to be a seasonal trend in nitrate concentrations and occasionally over the period of record there are increases in the nitrate concentration at the WWTP, CC -01, and CC -02. The available data for STC-02 show nitrate concentrations ranged from non -detect to 5.4 mg/L and averaged 1.0 mg/L.
• San Timoteo 1 Segment — STC-01 is the sole surface water monitoring location along this Segment. Nitrate concentrations at STC-01 range from non -detect to 11 mg/L and have a long-term average of 1.5 mg/L. The nitrate concentrations are less than those observed in upstream Segment Cooper's Creek 1, but generally follow the same trends. • San Timoteo 2 Segment — The surface water monitoring station YVWD-A is just upstream of the YVWD Henry N Wochholz RWRF DP001, both of which are at the downstream end point of this Segment. Generally, nitrate concentrations at YVWD-A are lower than the Henry N Wochholz RWRF discharge. Nitrate concentrations at YVWD-A range from non -detect to 9.7 mg/L and have a long-term average of 1.4 mg/L, while nitrate concentration for the Henry N Wochholz RWRF discharge range from non -detect to

27.7 mg/L and have a long-term average of 4.9 mg/L. Nitrate concentrations were much higher in the effluent of the Henry N. Wochholz RWRF DP001 prior to the implementation of a new denitrification process at the plant in 2009, and averaged 15 mg/L at that time. Since 2009, nitrate concentrations at Henry N. Wochholz RWRF averaged 2.6 mg/L.

Overall, nitrate concentrations at the surface water monitoring locations decrease from upstream to downstream and follow the trends of the Beaumont WWTP discharge.

WEST YOST 94

Page 2201 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek 1 Segment
30 25
20 E
m 15
10 5
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 + Beaumont WWTP DP 001 • CC -01 CC -03 I STC-02
Note: Beaumont WWTP nitrate data starting in 2017 is total inorganic nitrogen (TIN) concentrations and likely over estimate nitrate -nitrogen San Timoteo 1 Segment
30 25
20 15
10 5
Nitrate (mg/L)
2002 2004
STC-01
2006 2008 2010 2012 2014 2016 2018 2020
2022
2024
San Timoteo 2 Segment
30 25
5 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 + Henry N Wochholz RWRF DP 001 • YVWD-A
w

WEST I YOST
Water. Engineered.

Legend
• Nitrate concentration in groundwater (variable shapes)

YVW D -A
Henry N
Wochholz
RWRF DP 001
▪ Cooper's Creek 1 Segment
▪ San Timoteo 1 Segment
San Timoteo 2 Segment
Yucaipa Creek
Coope ,
Beaumont sn'eek
WWTP DP 001
0 0.5 1 2 Miles
Notes:

1. Nitrate is reported as Nitrate -Nitrogen

2. milligrams per liter (mg/L)

3. Beaumont WWTP nitrate data starting in 2017 is represented as total inorganic nitrogen (TIN)

4. Henry N. Wochholz RWRF data is represented as monthly averages Nitrate -Nitrogen Concentrations in Surface Water
City of Beaumont AMMP
Author: AK
Date: 20241212
File: Figure 6-3_Nitrate Timeseries_SW WQ.grt

Page 2202 of 2775 ends

Figure 6-3

Cooper's Creek 1 Segment
900
800
700
600
500
0 400
H 300
200
100
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 Beaumont WWTP DP 001 N, CC -01 CC -03 / STC-02
San Timoteo 1 Segment
900
800
700
L 600 -
500
0 400 -
H 300 -
200 -
100
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 STC-01
San Timoteo 2 Segment
900
800
700
600
500
0 400
F- 300
200
100
w
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 + Henry N Wochholz RWRF DP 001 YVWD-A

WEST I YOST
Water. Engineered.

Legend
• TDS concentration in groundwater (variable shapes)
YVWD-A
Henry N
Wochholz
RWRF DP 001
STC-01
San 77;22
Cooper's Creek 1 Segment
San Timoteo 1 Segment
San Timoteo 2 Segment
Notes:

1. Total Dissolved Solids (TDS)

2. milligrams per liter (mg/L)
Yucaipa Creek
0 0.5 1
I �
STC-02
CC -03
CC -01
Coope
Beaumont r'rCYeek
WWTP DP 001
2 Miles
TDS Concentrations in Surface Water
City of Beaumont AMMP
Author: AK
Date: 20241212
File: Figure 6-4_TDS TimeSeries_SW W4grf

Page 2203 of 2775 ends

Figure 6-4

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT

6.2.2.2 Total Dissolved Solids (TDS)
Review of the surface water TDS data shown in Figure 6-4 indicates the following for each Study Area Segment:
• Cooper's Creek 1 Segment — The Beaumont WWTP DP001 discharges into Cooper's Creek in the upstream portion of this Segment, and surface water stations CC -01 and CC -03 are downstream of the discharge. Overall, the TDS concentration at CC -01 and CC -03 mimic the concentrations of the discharge from Beaumont WWTP DP001. The WWTP concentrations range from 160 to 700 mg/L and have a long-term average of 455 mg/L. TDS concentrations at CC -01 and CC -03 are less and have long-term averages of 416 and 422 mg/L, respectively.

Since 2023, when the Beaumont WWTP began full implementation of the RO system, the TDS concentrations decreased from an average of about 450 mg/L to an average of about 240 mg/L. A reduction in the TDS concentrations is also reflected in the downstream sites at CC -01 and CC -03 after 2023.

STC-02 is located in San Timoteo Creek tributary to Cooper's Creek and is often dry and only sampled after storm events. The available data for STC-02 show TDS concentrations ranged from 170 mg/L to 420 mg/L and averaged 255 mg/L. This site is not influenced by the Beaumont WWTP because it is on a different stream system. • San Timoteo 1 Segment — STC-01 is the sole surface water monitoring location along this Segment. TDS concentrations at STC-01 range from 220 mg/L to 750 mg/L and have a long- term average of 457 mg/L. Concentrations in this segment are slightly higher than the TDS concentrations observed in upstream Segment Cooper's Creek 1. Since 2023, the TDS concentrations at STC-01 decreased from an average of about 460 mg/L to an average of about 320 mg/L, in response to the decrease in TDS concentration from the Beaumont WWTP.
• San Timoteo 2 Segment — The surface water monitoring station YVWD-A is just upstream of the YVWD Henry N Wochholz RWRF DP001, both of which are at the downstream end point of this Segment. Generally, TDS concentrations at YVWD-A are higher than the two upstream segments and the Henry N Wochholz RWRF discharge. TDS concentrations at YVWD-A range from 220 mg/L to 750 mg/L and have a long-term average of 457 mg/L. TDS concentrations of the Henry N Wochholz RWRF discharge range from 230 mg/L to 640 mg/L and have a long-term average of 412 mg/L. TDS concentrations were higher in the effluent of the Henry N. Wochholz RWRF DP001 prior to the installation of a RO treatment system that began operating in 2016. Since 2016, TDS concentrations at Henry N. Wochholz RWRF averaged 290 mg/L.

Overall, TDS concentrations slightly increase as you move downstream from the Beaumont WWTP discharge in Cooper's Creek to YVWD-A in San Timoteo Creek just above the Henry N. Wochholz RWRF DP001. Additionally, concentrations in the Cooper's Creek surface water appear to follow the trends of the Beaumont WWTP DP001 TDS concentrations.

WEST YOST 97

Page 2204 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

6.3 Groundwater Levels
The following subsections describe historical groundwater levels and quality in the vicinity of the Study Area.

6.3.1 Groundwater Elevation Time Series
Figure 6-5 is a time series plot of groundwater levels (as elevation) for select monitoring, domestic, and agricultural wells in the Study Area. Figure 6-5 includes a map of the location of the wells within the NDVI analysis Segments and plots the data by Segment from upstream to downstream. The 11 wells included in Figure 6-5 were selected because they have a long historical record, are within the Study Area, and are in close proximity to the creeks. The groundwater level measurements are collected as part of the Maximum Benefit Monitoring Program. Most of the wells have data between 2005 and 2022, while some have a longer period of record dating back as far as the mid -1990's. Since 2015, the monitoring frequency at all the wells is semi-annual. Prior to 2015, water level measurements were more frequent at most of the wells, with either monthly manual measurements or high -frequency transducer readings (e.g. 1 -hour to 15 -minute intervals). The groundwater elevation data are summarized below. • Cooper's Creek 1 Segment — Since 2005, static groundwater levels at wells OBMW-1, OBMW-2, Ranch Well, Heartland Well, and 335645117024201 ranged from approximately 2,070 to 2,437 feet NAVD88.1° Groundwater elevations are higher in wells OBMW-1 and OBMW-2 than the Ranch Well indicating a groundwater flow gradient towards the creek.

Groundwater elevations are about 100 and 200 feet (ft) lower at the Heartland Well and 335645117024201 compared to Ranch Well indicating a groundwater flow gradient parallel to Cooper's Creek along profile. Groundwater elevations at the Heartland Well show pumping levels can decline up to 300 ft however static groundwater levels have remained relatively stable over the period of record. Overall, groundwater levels remained about the same at OBMW-1, OBMW-2, 335645117024201, and Heartland Well, and increased about 20 ft at Ranch Well. The larger increase in groundwater levels at the Ranch Well could be attributable to a decrease in groundwater pumping at this well. • San Timoteo Creek 1 Segment — Over the available period of record since 1994, groundwater levels at #427, Agri -Empire and #428, Agri -Empire #2 remained stable, ranging from approximately 2,124 to 2,125 ft NAVD88. These wells are screened in the lower aquifer and exhibit artesian conditions— hence groundwater is observed to be at or just below the top of casing. Although these wells are included in this analysis, they are not representative of shallow groundwater conditions along the creeks and a data gap exists for shallow groundwater levels within San Timoteo Creek 1 Segment.
• San Timoteo Creek 2 Segment — Over the available period of record since 2006, static groundwater levels at wells Fishermen's Retreat 2, ONE, "1," and YVWD GWMW-4 wells ranged from approximately 1,689 to 1,938 ft NAVD88. Groundwater elevations are higher in YVWD GMWM-4 compared to "1" indicating a groundwater flow gradient toward the creek.

Groundwater elevations are lower in YVWD GWMW-4 compared to Fishermen's Retreat 2 indicating a groundwater flow gradient along the channel and moving downstream. Overall, groundwater levels remained about the same at ONE, and decreased by about 5 ft at YVWD 1° Elevation data is referenced to the North American Vertical Datum of 1988 (NAVD88) in feet.

WEST YOST 98

Page 2205 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
GWMW-4, by about 8 ft at "1," and by about 34 ft at Fishermen's Retreat 2.11 The decrease in water level at Fishermen's Retreat 2 could be attributable to increased pumping and less frequent measurements that are not representative of static conditions.

Generally, groundwater elevations are highest in the Cooper's Creek Segment and decrease along Cooper's and San Timoteo Creeks, indicating a groundwater gradient moving downstream. Groundwater elevations have generally remained stable over the period of record with some wells slightly increasing and others slightly decreasing. Wells in proximity of Cooper's and San Timoteo Creeks exhibit slight responses to storm surface water flows with groundwater levels slightly increasing following storms.

Ranch Well, Heartland Well, Fishermen's Retreat 2, and One wells all exhibit large ranges in groundwater elevations due to static and pumping depth to water measurements. A data gap exists within San Timoteo 1 Segment for groundwater elevations in the shallow unconfined aquifer.

6.3.2 Groundwater Flow System
Figure 6-6 is a groundwater elevation contour map for spring 2022 which illustrates the current groundwater flow system in the Study Area. To develop the contours, groundwater elevations measured at selected wells in the spring of 2022 were plotted and interpolated across the Study Area to generate a potentiometric surface of the shallow water table. As discussed above, historical groundwater elevations have not fluctuated to a great extent over time. Therefore, the spring 2022 groundwater elevation contour map is representative of the flow system for the period of record of available data back to about 2005.

The consistency of groundwater elevations over time, and thus the flow system, is illustrated on Figure 6-5, which is a time history chart of elevations at 11 wells in the Study Area. The groundwater elevation contour map indicates that the direction of groundwater flow through the Study Area is towards the northwest and along the Cooper's and San Timoteo Creek channels from upstream to downstream.

6.3.3 Depth to Groundwater
Figure 6-6 shows the Spring 2022 depth to groundwater measurement at each of the wells in the Study Area used to prepare groundwater elevation contours.12 Depth to groundwater measurements ranged from approximately 23 feet below ground surface (ft bgs) to 123 ft bgs within the Study Area.

Depth to groundwater was evaluated both perpendicular to and along the stream channels. Depths to groundwater along contour lines that are perpendicular to the stream channel indicate that groundwater is shallower near the stream channel and deepens with distance away from the Study Area. For example, at the Ranch Well, which is immediately adjacent to the stream, depth to water is about 23 ft bgs as compared to the OBMW wells away from the stream channel with depths to water of about 90 to 120 ft bgs. Another example pair of wells at the opposite end of the Study Area is YVWD GWMW-4 and well "1."
11 It should be noted that the reported difference in elevation at Fishermen's Retreat 2 is around 78 ft over the period of record, however the groundwater elevations between 2019 and 2022 likely do not represent static water levels.

Based on historical trends, we estimated a static level for spring 2022 to be approximately 1900 feet NAVD88. 12 Depth to water contours were not developed because they would be estimated using the available 10 -meter USGS digital elevation model (DEM) of the ground surface. A 10 -meter resolution does not provide a high enough resolution needed of the ground surface elevation for these narrow areas along the creek in the Study Area WEST YOST 99

Page 2206 of 2775 ends

City of Beaumont
May 2025

Groundwater Elevation (ft NAVD88)
Cooper's Creek 1 Segment
2,450
2,400
c 2,350
$ 2,300
0 2,250
cu 2,200
W
L
a,
0 c
0 C7
2,150
2,100
2,050
2,000
T T r _
1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 San Timoteo 1 Segment
2,450
^ 2,400
Co
co
2,350
$ 2,300
0 2,250
CC
v 2,200
a; 2,150
CC
c 2,100
2 2,050
2,000
1994
F
F
F
F
F
F
P
F
F
F
F
F
1996
San Timoteo 2 Segment
2,000
1,950
1,900
1,850
1,800
1,750
1,700
1,650
1,600
1,550
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
r
1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 WEST I YOST Author: AKDate: 20241212
Water. Engineered. File: Figure 6-5_GWL_3_Segments_r2.grf Cooper's Creek 1 Segment
Groundwater Elevations at Wells (Perforated Interval Depth) OBMW-1 (142.8-162.8 ft-bgs)
OBMW-2 (97.6-117.6 ft-bgs)
Ranch Well (n/a)
335645117024201 (n/a)
Heartland Well (160-540 ft-bgs)
San Timoteo 1 Segment
Groundwater Elevations at Wells (Perforated Interval Depth) #427, Agri -Empire (n/a)
#428, Agri -Empire #2 (n/a)
San Timoteo 2 Segment
Groundwater Elevations at Wells (Perforated Interval Depth) Fishermen's Retreat 2 (70-615 ft-bgs)
One (110-590 ft-bgs)
1 (140-245 ft-bgs)
YVWD GWMW-4 (65-80 ft-bgs)
Notes:

1. Feet below ground surface (ft-bgs)

1. Wells listed in order of decreasing elevation downstream

3. #427, Agri -Empire and #428, Agri -Empire #2 are screened in the deeper confined aquifer and exhibit artesian conditions
YVWD GWMW-4
ONE
Henry N Wochholz
RWRF DP 001
Yucaipa Creek
Fishermen's Retreat 2
San 7y
p
#427, Agri -Empire 335645117024201
O' Heartland Well
OBMW-2 OBMW-1
#428, Agri -Empire #2
-*
Cooper's Creek 1 Segment
San Timoteo 1 Segment
San Timoteo 2 Segment
Groundwater Monitoring
Well
Ranch Well Coop
Beaumont s'(7-eek
WWTP DP 001
0 0.5 1
l 1
2 Miles
NA
Groundwater Elevations at Select
Well Locations

Page 2207 of 2775 ends

Figure 6-5

YVWn1GWMW-4
17151;38
(23.26)
al O ONE
! I
o
) coo f o 1870.53
'" ^i CO/ 0/ o (3613)/
1718.85
(129.93)
i
Prepared by:

Prepared for:

WEST I YOST
335645117024201
2221.05
(26.86)
2 2.000 4,000
Heartland Well
2282.97
(29.7)
Miles

Page 2208 of 2775 ends

OBMW-4
2420.63
OBMW-3 (122.98)
2434.98
(89.65)
Ranch Well
2416.05
(22.59)
2 2443.11
(101.1)
OBM W-1
2421.78
(118.9)
Beaumont
WWTP DP 001
City of Beaumont
Adaptive Management and _-- 'A.NN
Mitigation Plan (AMMPJ BEAUM0N1
OBMW-1 Well Identification
2421.78 Groundwater elevation (ft)
(118.9) \ Depth to Water (ft bgs)
2420 -
20 -ft Estimated Groundwater
Elevation- Spring 2022
• WWTP Discharge Point (active)
♦ Contouring Well
Study Area
San Timoteo GMZ
Beaumont GMZ
Riparian Zone
Geology
Water -Bearing Sediments
Unconsolidated to Semi -
J consolidated Quaternary Alluvium
Consolidated and Semi -Consolidated
Formations
San Timoteo Formation
Undifferentiated Pre -Tertiary
Igneous and Metamorphic
Crystalline Rocks
Notes:

1. Riparian Zone was drawn using tree line.

2. GMZ - groundwater management zone

3. WWTP - wastewater treatment plant

4. Spring 2022 groundwater elevation and depth to water for Fishermen's Retreat 2 well was estimated.

5. Elevation data is referenced to the North American Vertical Datum of 1988 (NAVD 88).
0 Ontario
Corona
naheim
Santa Ana
San Bernardino
National Forest
Riversr710
O
Mpnifpp
i .114.43 f
San Gorgoni
Pass
Groundwater Elevation
Spring 2022
City of Beaumont AMMP
Figure 6-6

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
Along the stream channels, Ranch Well, Heartland Well, 335645117024201, ONE, and YVWD GWMW-4 wells all exhibit shallow depth to waters (within 40 feet of ground surface). Fishermen's Retreat 2 well exhibits a slightly deeper depth to groundwater even though it is adjacent to the San Timoteo Creek. This is an estimated value and all recent data collected suggests that depth to groundwater measurements have been influenced by nearby pumping activities. Based on the monitoring sites, depth to groundwater appears to be shallowest near the outfalls of the Beaumont WWTP DP001 and Henry N. Wochholz RWRF DP001.

6.4 Groundwater Quality
Groundwater quality data is collected at wells throughout the Study Area as part of the Maximum Benefit Monitoring Program. Water quality monitoring is performed at wells at a minimum frequency of once every three years. Twelve wells were selected to characterize groundwater quality in this Report because they have a long historical record, are within the Study Area, and close proximity to the creeks. These wells are a mix of agriculture, monitoring, and domestic wells. Figures 6-7 and 6-8 show the location of the wells relative to the Study Area and NDVI analysis Segments, and time -histories of the nitrate and TDS concentrations for each well, by Segment. Also shown in the time history charts are the nitrate and TDS concentrations of the Beaumont WWTP and Henry N Wochholz RWRF discharges. The period of record of available data is generally from 2005 to 2022, but data is available at some sites as far back as 2001.

6.4.1 Nitrate
Review of the nitrate data on Figure 6-7 indicates the following for each Study Area Segment:
• Cooper's Creek 1 Segment —Since 2005, nitrate concentrations ranged from 0.48 mg/L to 17 mg/L at the wells along this Segment. Generally, nitrate concentrations are higher at the wells upstream (OBMW-1, OBMW-2, and Ranch Well) than the downstream well (Heartland Well). No nitrate data is available for 335645117024201. Over the historical period of record, nitrate concentrations increased at Ranch Well and OBMW-2, decreased at OBMW-1, and remained about the same at Heartland Well. Nitrate concentrations were generally lower than the Beaumont WWTP discharge long-term average concentration of

4.2 mg/L at all wells with the exception of Heartland Well. • San Timoteo Creek 1 Segment — Since 2005, nitrate concentrations ranged from non -detect to 3.4 mg/L at the wells along this Segment. Generally, nitrate concentrations are lower when compared to the upstream segment and are higher in the upstream wells (San Tim -2B/1 and San Tim -2B/2) than the downstream well (SanTim-1). Over the historical period, nitrate concentrations decreased at San Tim -2B/1 and SanTim-1 and remained about the same at San Tim -2B/2. Nitrate concentrations at all wells were generally lower than the Beaumont WWTP discharge long-term average concentration of 4.2 mg/L. • San Timoteo Creek 2 Segment —Since 2005, nitrate concentrations ranged from non -detect to 47 mg/L at the wells along this Segment. Generally, nitrate concentrations are lower than the upstream segments with the exception of well "1." Concentrations are highest farther from the channel (well "1") compared to those closer (Fishermen's Retreat 2, ONE, and YVWD GWMW-4). No noticeable trends are apparent within this Segment. With the exception of well "1," nitrate concentrations at all wells were generally lower than the Beaumont WWTP discharge long-term average concentration of 4.2 mg/L.

WEST YOST
102

Page 2209 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek 1 Segment
Nitrate (mg/L)
50 45
40 35
30 25
20 15
10 5
••••/••�
•/
••••/•/•••
// /••
S/•
4frittlit
++
!ft
.....good.444_
440*

2002
2004 2006 2008 2010 2012 2014 2016 2018 2020
Beaumont WWTP DP 001
Ranch Well
Heartland Well • OBMW-1 OBMW-2
Note: Beaumont WWTP nitrate data starting in 2017 is total inorganic nitrogen (TIN) concentrations and likely over estimate nitrate -nitrogen San Timoteo 1 Segment
50 45
40 35
30 25
20 15
10 5
F1
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022
San Tim -1 / San Tim -2B/1 — San Tim -2B/2
Nitrate (mg/L)
2022
San Timoteo 2 Segment
Nitrate (mg/L)
50 45
40 35
30 25
20 15
10 5
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 + Henry N Wochholz RWRF DP 001 1 A Fishermen's Retreat 2 A YVWD GWMW-4 One
W
2024
Legend
• Nitrate concentration in groundwater (variable shapes) Henry
N Wochholz

RWRF DP
001
2024
•
• • • •
•
44+
+
+„+
+
4 ohadof+4AdoAbtookimii
. +A..1-44+40+44-#.

WEST I YOST
Water. Engineered.

YVWD GWMW-4
/ONE
f
San 77
Yucaipa Creek
Fishermen's Retreat 2
SanTim-1
San Tim -2B/1
o
San Tim -2B/2
▪ Cooper's Creek 1 Segment
- San Timoteo 1 Segment
San Timoteo 2 Segment
0 0.5 1
335645117024201
Heartland Well
.o
Ranch Well
Beaumont
WWTP DP 001
2 Miles
OBMW-1
OBMW-2
CYeek
Notes:

1. Nitrate is reported as Nitrate -Nitrogen

2. milligrams per liter (mg/L)

3. Beaumont WWTP nitrate data starting in 2017 is represented as total inorganic nitrogen (TIN)

4. Henry N. Wochholz RWRF data is represented as monthly averages Nitrate -Nitrogen Concentrations in Groundwater
City of Beaumont AMMP
Author:AK
Date: 20241212
File: Figure 6•7_Nitrate TimeSeries_GWW4grf

Page 2210 of 2775 ends

Figure 6-7

Cooper's Creek 1 Segment
1,400
1,200
1,000
J p
E 800
600
400
200
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 Beaumont WWTP DP 001
• Ranch Well
San Timoteo 1 Segment
1,400
1,200
1,000
J
iT
E
to
I-
800
600
400
200
Heartland Well • OBMW-1
335645117024201
OBMW-2
i
it
1 ■Daiiki •
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 San Tim -1 • San Tim -2B/1 San Tim -2B/2
San Timoteo 2 Segment
1,400
1,200
1,000
J
F
800
600
400
200
w
00 _
I1
, AAAA
+F
+
2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 + Henry N Wochholz RWRF DP 001 1 ♦ Fishermen's Retreat 2 A YVWD GWMW-4 • One
WEST / YOST Author: AK
Legend
• TDS concentration in groundwater (variable shapes)
Henry
N Wochholz

RWRF DP
001
YVWD GWMW-4
ONE
1 San T,
Yucaipa Creek
Fishermen's Retreat 2
o
San Tim -2B/2
Cooper's Creek 1 Segment
ji San Timoteo 1 Segment
San Timoteo 2 Segment
Notes:

1. Total Dissolved Solids (TDS)

2. milligrams per liter (mg/L)
SanTim-1
San Tim -2B/1
0 0.5 1
335645117024201
Heartland Well
OBMW-1
a�—OBMW-2
Coo
Ranch Well
Beaumont
WWTP DP 001
2 Miles
TDS Concentrations in Groundwater
City of Beaumont AMMP
Water. Engineered. Fineered. Fi e:zoze6-8le: Figure -8_TDS TimeSeries_GWWQ.grf

Page 2211 of 2775 ends

Figure 6-8

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
Generally, nitrate concentrations are lower at monitoring locations adjacent to the creek channels and higher away from the channels. The exception to this is Ranch Well (located adjacent to Cooper's Creek 1 Segment and near the channel). Concentrations here consistently are higher than the Beaumont WWTP discharge long-term average concentration and upgradient wells (OBMW-1 and OBMW-2). The source of this localized nitrate is likely from agricultural practices at the site of the well. Well "1" also exhibits high concentrations of nitrate, which is also likely due to agricultural practices near the well site. Low nitrate surface water recharge of the aquifers via the stream bed is likely the cause for the observed gradient in nitrate concentrations in groundwater with proximity to the creeks.

6.4.2 Total Dissolved Solids
Review of the TDS data on Figure 6-8 indicates the following for each Study Area Segment:
• Cooper's Creek 1 Segment — Since 2001, TDS concentrations ranged from 190 mg/L to 900 mg/L at the wells along this Segment. Generally, TDS concentrations are higher at the wells upstream (OBMW-1, OBMW-2, and Ranch Well) than the downstream well (Heartland Well). Only one TDS sample result is available for downstream well 335645117024201. Over the historical period, TDS concentrations increased at Ranch Well, decreased at OBMW-1, and remained about the same at OBMW-2 and Heartland Well. TDS concentrations were generally higher than the Beaumont WWTP discharge long term average concentration of 455 mg/L, with the exception of Heartland Well, which was generally lower. • San Timoteo 1 Segment —Since 2010, TDS concentrations ranged from 180 mg/L to 474 mg/L at the wells along this Segment. Generally, TDS concentrations are lower when compared to the upstream segment and higher at the downstream well within this Segment (SanTim-1) compared to the upstream wells (SanTim-2B/1 and SanTim-2B/2). Over the historical period of record, TDS concentrations remained relatively stable at the wells within the San Timoteo 1 Segment and were generally lower than the Beaumont WWTP discharge long term average concentration of 455 mg/L.
• San Timoteo 2 Segment — Since 2007, TDS concentrations ranged from 360 mg/L to 1,100 mg/L at the wells along this Segment. Generally, TDS concentrations are higher than the San Timoteo 1 Segment and comparable to Cooper's Creek 1 Segment. Within the Segment, TDS concentrations are higher at the middle and downstream wells (One and YVWD GWMW-4) and lower at the upstream well (Fishermen's Retreat 2). Well "1" is located off the channel of the creek and exhibits the highest concentrations within the three Segments. Over the historical period of record TDS concentrations remained relatively stable at the wells within the San Timoteo 2 Segment and were generally higher than the Beaumont WWTP discharge long term average concentration of 455 mg/L, with the exception of Fishermen's Retreat 2 which was generally below.

Generally, TDS concentrations are lower at monitoring locations adjacent to the creek channels and higher away from the channels. This is likely due to low-TDS surface water recharging the shallow groundwater via the stream bed. The exception to this is Ranch Well, which is located adjacent to Cooper's Creek 1 Segment and near the channel. Concentrations at Ranch Well are consistently high and likely due to a local agricultural source. Well "1" exhibits the highest concentrations of TDS in all three segments which is located off the channel and adjacent to San Timoteo 2. As discussed above, local agricultural is likely the cause of the high TDS at well "1."

WEST YOST
105

Page 2212 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

7.0 FACTORS THAT IMPACT RIPARIAN HABITAT
This section describes the physical factors that have potential to impact the health and extent of the riparian habitat in the Study Area, and how historical changes in these factors over time relate to observed changes in NDVI. For the AMMP, it will be important to understand the relationship of these physical factors to reductions in Beaumont WWTP discharge to Cooper's Creek to demonstrate if and how reduced discharge is affecting the riparian habitat. The following factors that can impact the Study Area riparian habitat and analyzed for this Report include:

1. Surface water flows

2. Groundwater levels

3. Hydrological impacts to biological resources

4. Other climate factors

5. Wildfires

6. Invasive species and pests
This section also identifies any datasets related to these factors that are unavailable or sparse and that if collected through the AMMP could improve the characterization of the factors that are potentially influencing any observed changes in riparian habitat extent and health over time.

7.1 Surface Water Flows
Contributing sources to surface water flow of the Study Area creeks include wastewater discharges, precipitation runoff (storm flows), and potentially rising groundwater. As discussed in Sections 2 and 6, absent wastewater discharges, the creeks in the Study Area would be ephemeral. Thus, a reduction in Beaumont WWTP discharges to Cooper's Creek will likely result in lower surface water flows in Cooper's Creek and San Timoteo Creek.

To evaluate the historical relationship of surface water flow and riparian habitat health, precipitation, surface water flow, and Beaumont WWTP discharge were compared to the historical NDVI. Figures 7-1 through 7-3 are time series charts that compare the following datasets for each NDVI analysis Segment defined in Section 5 of this Report (Cooper's Creek 1, San Timoteo 1, and San Timoteo 2) for the period of 1984 to 2023 (where available):
• Annual precipitation totals (inches) for the San Timoteo Watershed (described in Section

2.3.1). Also shown is the long-term average precipitation and CDFM based on the entire 128 -year period of record available from the PRISM dataset of 1895 to 2023. • Annual (afy) and daily (mgd) Beaumont WWTP discharge at DP001 to Cooper's Creek (described in Section 6.1). Annual records are available since 1989 and daily records since 2006.
• Bi-weekly surface water flow measurements (cfs) collected for the Maximum Benefit Monitoring Program (described in Section 6.2.1). Note that this dataset is not available until 2005, after the volume of Beaumont WWTP discharges began to increase at a high rate. • Average Growing Season NDVI (described in Section 5.3) for the Focus Areas within each Segment
The analysis of the data is described below for each Segment.

WEST YOST 106

Page 2213 of 2775 ends

City of Beaumont
May 2025

E
O
4-
00 rci
U
U
V7
Beaumont WWTP
c▪ o
Precipitation (inches)
Surface Water Flow (cfs)
45 40
35 30
25 20
15 10
5 0
45 40
35 30
25 20
15 10
5 0
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000

0.8 0.7

0.6 0.5
z

0.4 0.3

0.2 0.1
f
_ _ -
\. -
1 I
mi l l i
I I I
I1
I I 1 I -I
I I1
11141114 vt""14104441441#1004
III
I
i ll
_. woman
1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 2021 2023 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 2021 2023

WEST YOST
Water. Engineered.

Author: AK
Date: 20241212
File: Figure 7-1_ Discharge_ GWLs_StudyArea-A_v2.grf

Page 2214 of 2775 ends

110
Precipitation (inches)
90 Cumulative Departure From the Mean Precipitation (CDFM) 70 Annual Precipitation
Average Annual Precipitation for Water Years 1895-2023
50 LL (19.3 inches)
CC
30 10 Surface Water Flow
CC -01 (cfs)
-10 — CC -03 (cfs)
Beaumont WWTP DP -001 Daily Discharge (Daily - cfs)
Beaumont WWTP DP -001 Discharge (Annual - mgd)

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1
Average Growing Season NDVI
(Mann -Kendall Trend Result for 1984-2023; 1984-2003; 2004-2023) t FA01 (increasing; increasing; increasing)
FA02 (increasing; no trend; increasing)
a FA03 (increasing; increasing; increasing)
FA04 (increasing; no trend; increasing)
t FA05 (increasing; no trend; increasing)
FA06 (increasing; no trend; increasing)
�— Cooper's Creek 1 (increasing; increasing; increasing) FA06
- Cooper's Creek
1 Segment
S
Focus Areas
Surface Water
Monitoring
Location
Beaumont
WWTP DP 001
FA05
CC -03
COOPe,,
''C/-ee k
0 0.25 0.5
I
FA04
CC -01 FA02
‘ FA01
FA03 Beaumont
WWTP DP 001
N
1 Miles
A
Precipitation, Surface Water Flow,
and WWTP Discharge versus NDVI
Cooper's Creek 1 Segment for 1983-2023
City of Beaumont AMMP
Figure 7-1

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT

7.1.1 Cooper's Creek 1 Segment
Based on the interpretations previously described in Sections 2, 5, and 6, and integrated together in Figure 7-1, the relationship of surface flows and Beaumont WWTP discharges in the Cooper's Creek 1 Segment appears as follows:
• Since the start of the available record in 2005, surface flow at CC -01 generally mimics the daily discharge at Beaumont DP001 and increases as discharge increases from the plant. It is important to note that the bi-weekly measurements are an instantaneous measurement in time, whereas the DP001 data is the average flow rate over a 24 -hour period. Thus, differences between the two sites could be attributable to daily fluctuations in discharge rates. Peak deviations from the discharge rate occur during precipitation events. • Since the start of the available record in 2013, surface flow at CC -03 generally mimics the daily discharge at DP001 and CC -01 and also shows peak deviations from the discharge rate occur during precipitation events. The flow is generally less than at CC -01 indicating that the reach from CC -01 to CC -03 is a losing reach, such that flow is being lost as infiltration to groundwater and/or riparian vegetation uptake.
• Based on the available surface water flow data, it is not possible to determine how much the surface flow increased due to the post -2004 increase in Beaumont WWTP discharges. • The CDFM illustrates that there has been a long-term dry period in the Study Area that has persisted since about 1999 as shown by the downward trending CDFM. The dryness of the climate does not appear to have an impact on surface flows given they have remained relatively consistent with the DP001 discharges. Thus, indicating that the Beaumont WWTP discharge is the primary driver of year-round surface flow in the Study Area and not precipitation.
• All NDVI Focus Areas have statistically increasing trends over the entire 1984 to 2023 period of record. However, only two of the sites show a statistically increasing trend for the 1984 to 2003 period: FA01 and FA03. The remaining four areas—FA02, FA04, FA05, and FA05—had "no trend" in this early half of the data record, indicating stable NDVI estimates from 1984 to 2003. This suggests that Beaumont WWTP flows only began to significantly improve riparian habitat extent beyond the immediate vicinity of DP001 at the post -2004 increased discharge rates.
• Since 2004, the NDVI of all Focus Areas had a statistically increasing trend. These increases occurred at the same time that the discharge from Beaumont WWTP was increasing. The largest increase in NDVI within this time period was at FA03, which is located immediately downstream of the Beaumont WWTP DP001, indicating a direct relationship between Beaumont WWTP discharges and riparian habitat health and extent as measured by NDVI. • The two Focus Areas with the greatest increase in NDVI since 1984 are FA03 and FA06. Both had an NDVI of less than 0.3 in 1984 and increased to a maximum of about 0.60 and 0.70, respectively, around 2015/2026. While it is clear that the Beaumont WWTP is the direct cause of the significantly increased NDVI at FA03, there may be other factors supporting riparian habitat at FA06, such as increased surface flow resulting from urban development.

However, absent historical records of surface water flow prior to 2005, it is difficult to make any conclusion about the relative impact each factor could have had on surface flow and thus riparian health at FA06.

WEST YOST
108

Page 2215 of 2775 ends

City of Beaumont
May 2025

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report

BEAUMONT
• FA05 was the only Focus Area to have robust and consistent riparian habitat health with an NDVI ranging from about 0.6 to 0.7 prior to about 2007. All other sites were below 0.5 prior to 2007. This suggests that Beaumont WWTP flows are not the primary source of water supporting riparian habitat at FA05.
• The Beaumont WWTP annual discharge decreased by approximately 500 of over the 2020 to 2023 period. There was no concurrent decrease in NDVI at the Focus Areas over this period, except for a decrease of less than 0.05 at FA03 and FA05 from 2022 and 2023. Though it may take more time for an impact to the riparian health to manifest, the data initially suggest that the recent decreases in discharge did not negatively impact riparian habitat health in the Study Area.

The observed responses of the riparian habitat health in Cooper's Creek 1 Segment indicate there is a positive relationship between riparian habitat health and increased surface water flows, and more specifically to Beaumont WWTP discharges that appear to be the main contributor of flow in the Study Area.

7.1.2 San Timoteo 1 Segment
Based on the interpretations previously described in Sections 2, 5, 6, 7.1.1., and integrated together on Figure 7-2, the relationship of surface flows and Beaumont WWTP discharges in the San Timoteo 1 Segment appears as follows:
• Since the start of the available record in 2005, surface water flow at STC-01 generally mimics the daily discharge at Beaumont WWTP DP001 and the upstream surface water monitoring locations (CC -01 and CC -03). The streamflow record shows peak deviations from the discharge rate occur during precipitation events, as well as additional 'trough' deviations from inter -storm periods. The flow is generally less than the upstream stations, indicating that the reach between CC -03 and STC-01 is a losing reach, such that flow is being lost to infiltration and/or riparian vegetation uptake.
• Based on the available surface water flow data, it is not possible to determine how much the surface water flow increased due to the post -2004 increased in Beaumont WWTP discharges. • The CDFM illustrates that there has been a long-term dry period in the Study Area that has persisted since about 1999 as shown by the downward trending CDFM. They dryness of the climate does not appear to have an impact on surface flows given they have remained relatively consistent with the DP001 discharges. Thus, indicating that the Beaumont WWTP discharge is the primary driver of year-round surface flow in the Study Area and not precipitation.
• All NDVI Focus Areas have statistically increasing trends over the entire 1984 to 2023 period of record. However, only one of the sites showed an increasing trend for the 1984 to 2003 period: FA08. The remaining Focus Area, FA07, had "no trend" in this early half of the data record, indicating stable NDVI estimates from 1984 to 2003. This suggests that Beaumont WWTP flows only began to improve riparian habitat extent beyond the immediate vicinity of DP001 at the post -2004 increased discharge rates.
• Since 2004, the NDVI of the upstream Focus Area (FA07) had a statistically increasing trend, while the downstream Focus Area (FA08) had "no trend." The trends occurred while the discharge from Beaumont WWTP was increasing.

WEST YOST
109

Page 2216 of 2775 ends

City of Beaumont
May 2025

Precipitation (inches)
Surface Water Flow (cfs)
45 40
35 30
25 20
15 10
5 0
45 40
35 30
25 20
15 10
5 0
4,500
a-
4,000
o 3,500
v 3,000
o co 2,500
N g 2,000
m 1,500
1,000

0.8 0.7

0.6 0.5
z

0.4 0.3

0.2 0.1
w
-
f
1 I I I
I
A
I I -I
I !■I
I I I1 1
I
I I I 1 1
1 ii 1
I-1
1 1 1 1-1
I I-1 1-
wilitittovorc itthiriii.

I
i ll
_. Emma 1
1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 2021 2023 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 2021 2023 110
90 70
50 30
10 -10

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1
CDFM (inches)
Precipitation (inches)
Cumulative Departure From the Mean Precipitation (CDFM) Annual Precipitation
Average Annual Precipitation for Water Years 1895-2023
(19.3 inches)
Surface Water Flow
STC-01 (cfs)
Beaumont WWTP DP -001 Daily Discharge (Daily - cfs)
Beaumont WWTP DP -001 Discharge (Annual - mgd)
Average Growing Season NDVI
(Mann -Kendall Trend Result for 1984-2023; 1984-2003; 2004-2023) t FA07 (increasing; no trend; increasing)
—0— FA08 (increasing; increasing; no trend)
—•— San Timoteo 1 (increasing; no trend; increasing)
STC-01
S
San Timoteo 1
Segment
Focus Areas
Surface Water
Monitoring Location
0 0.25 0.5
Precipitation, Surface Water Flow,
and WWTP Discharge versus NDVI
San Timoteo 1 Segment for 1983-2023
City of Beaumont AMMP

WESTI YOST
Water. Engineered.

Author: AK
Date: 20241216
File: Figure 7-2 Discharge GWLs StudvArea-B v2.grf

Page 2217 of 2775 ends

Figure 7-2

Cooper's Creek and San Timoteo Creek Habitat
Characterization and Sustainability Report BEAUMONT
• Increases in NDVI at both Focus Areas (FA07 and FA08) since 1984 are generally lower when compared to Cooper's Creek 1 Segment. Both had an NDVI of less than 0.6 in 1984 and increased to about 0.70 and 0.69, respectively, by 2023. Because of the higher initial value of NDVI and lower response to Beaumont WWTP discharges, there may be other factors supporting riparian habitat at these Focus Areas, such as increased surface flow resulting from urban development. However, absent historical records of surface water flow prior to 2005, it is difficult to make any conclusion about the relative impact each factor could have had on surface flow and thus riparian health at FA07 and FA08. • The Beaumont WWTP annual discharge decreased by approximately 500 of over the 2020 to 2023 period. There was no concurrent decrease in NDVI at the Focus Areas over this period.

Though it may take more time for an impact to the riparian health to manifest, the data initially suggest that the recent decreases in discharge did not negatively impact riparian habitat health in the Study Area.

The observed responses of the riparian habitat health in San Timoteo 1 Segment indicate there is a positive relationship between riparian habitat health and increased surface water flows, and more specifically to Beaumont WWTP discharges that appear to be the main contributor of flow in the Study Area. However, the response in this Segment is noticeably less than that of Cooper's Creek 1, indicating less of an influence from Beaumont WWTP discharges.

7.1.3 San Timoteo 2 Segment
Figure 7-3 has the added dataset of the Henry N. Wochholz RWRF discharge that occurs at the downstream end of the Segment. Based on the interpretations previously described in Sections 2, 5, 6,

7.1.1, and integrated together in Figure 7-3, the relationship of surface flows and Beaumont WWTP discharges in the San Timoteo 1 Segment appears as follows:
• Since the start of the available record in 2005, surface water flow at YVWD-A generally mimics the daily discharge at Beaumont WWTP DP001 and the upstream surface water monitoring locations (STC-01, CC -01, and CC -03). The streamflow record shows peak deviations from the discharge rate occur during precipitation events, as well as additional 'trough' deviations from inter -storm periods. The flow is generally less than the upstream stations, indicating that the reach between STC-01 and YVWD-A is a losing reach, such that flow is being lost to infiltration and/or riparian vegetation uptake. • Based on the available surface water flow data, it is not possible to determine how much the surface water flow increased due to the post -2004 increased in Beaumont WWTP discharges. • The CDFM illustrates that there has been a long-term dry period in the Study Area that has persisted since about 1999 as shown by the downward trending CDFM. They dryness of the climate does not appear to have an impact on surface flows given they have remained relatively consistent with the DP001 discharges. Thus, indicating that the Beaumont WWTP discharge is the primary driver of year-round surface flow in the Study Area and not precipitation. • All NDVI Focus Areas had statistically increasing trends over the entire 1984 to 2023 period of record. However, only one of the sites showed an increasing trend for the 1984 to 2003 period: FA10. The remaining focus area, FA09, had a decreasing trend in this early half of the data record, indicating decreasing NDVI estimates from 1984 to 2003. This suggests that Beaumont WWTP flows only began to improve riparian habitat extent beyond the immediate vicinity of DP001 at the post -2004 increased discharge rates.

WEST YOST
111

Page 2218 of 2775 ends

Beaumont City CouncilJune 17, 2025

Beaumont City Council
June 17, 2025