2025 12 19 Stormwater Report Rev 1

Existing Conditions Proposed Conditions Difference Time 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year (Min) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) 1020 0.392 0.628 1.159 0.388 0.625 1.157 -0.004 -0.003 -0.002 1026 0.384 0.616 1.136 0.381 0.613 1.134 -0.004 -0.003 -0.002 1032 0.377 0.604 1.114 0.373 0.601 1.112 -0.004 -0.003 -0.002 1038 0.369 0.592 1.091 0.366 0.589 1.089 -0.004 -0.003 -0.002 1044 0.362 0.579 1.069 0.358 0.576 1.067 -0.004 -0.003 -0.002 1050 0.354 0.567 1.046 0.351 0.564 1.044 -0.004 -0.003 -0.002 1056 0.346 0.555 1.023 0.343 0.552 1.021 -0.003 -0.003 -0.002 1062 0.339 0.543 1.001 0.335 0.540 0.999 -0.003 -0.003 -0.002 1068 0.332 0.531 0.979 0.328 0.528 0.977 -0.003 -0.003 -0.002 1074 0.324 0.519 0.957 0.321 0.517 0.956 -0.003 -0.003 -0.002 1080 0.317 0.507 0.935 0.314 0.505 0.934 -0.003 -0.003 -0.002 1086 0.309 0.495 0.913 0.306 0.493 0.911 -0.003 -0.003 -0.002 1092 0.303 0.485 0.893 0.300 0.482 0.891 -0.003 -0.002 -0.002 1098 0.298 0.478 0.881 0.296 0.475 0.879 -0.003 -0.002 -0.002 1104 0.296 0.474 0.873 0.293 0.471 0.871 -0.003 -0.002 -0.002 1110 0.294 0.470 0.867 0.291 0.468 0.865 -0.003 -0.002 -0.002 1116 0.292 0.467 0.861 0.289 0.465 0.859 -0.003 -0.002 -0.002 1122 0.290 0.464 0.856 0.287 0.462 0.854 -0.003 -0.002 -0.002 1128 0.288 0.461 0.850 0.286 0.459 0.849 -0.003 -0.002 -0.002 1134 0.287 0.459 0.846 0.284 0.457 0.844 -0.003 -0.002 -0.002 1140 0.285 0.456 0.839 0.282 0.453 0.838 -0.003 -0.002

0.002 1134 0.287 0.459 0.846 0.284 0.457 0.844 -0.003 -0.002 -0.002 1140 0.285 0.456 0.839 0.282 0.453 0.838 -0.003 -0.002 -0.002 1146 0.283 0.452 0.834 0.280 0.450 0.832 -0.003 -0.002 -0.002 1152 0.281 0.449 0.828 0.278 0.447 0.826 -0.003 -0.002 -0.002 1158 0.279 0.447 0.823 0.276 0.444 0.821 -0.003 -0.002 -0.002 1164 0.277 0.443 0.817 0.275 0.441 0.815 -0.003 -0.002 -0.002 1170 0.275 0.440 0.811 0.273 0.438 0.809 -0.003 -0.002 -0.002 1176 0.273 0.437 0.806 0.271 0.435 0.804 -0.003 -0.002 -0.002 1182 0.272 0.434 0.800 0.269 0.432 0.799 -0.003 -0.002 -0.001 1188 0.270 0.432 0.796 0.267 0.430 0.794 -0.003 -0.002 -0.001 1194 0.268 0.428 0.789 0.265 0.426 0.788 -0.003 -0.002 -0.001 1200 0.266 0.425 0.783 0.263 0.423 0.782 -0.002 -0.002 -0.001 1206 0.264 0.422 0.778 0.262 0.420 0.776 -0.002 -0.002 -0.001 1212 0.262 0.420 0.773 0.260 0.418 0.771 -0.002 -0.002 -0.001 1218 0.260 0.416 0.767 0.258 0.414 0.765 -0.002 -0.002 -0.001 1224 0.258 0.413 0.761 0.256 0.411 0.759 -0.002 -0.002 -0.001 1230 0.257 0.410 0.755 0.254 0.408 0.754 -0.002 -0.002 -0.001 1236 0.255 0.407 0.750 0.252 0.405 0.749 -0.002 -0.002 -0.001 1242 0.253 0.405 0.745 0.251 0.403 0.744 -0.002 -0.002 -0.001 1248 0.251 0.401 0.739 0.249 0.399 0.738 -0.002 -0.002 -0.001 1254 0.249 0.398 0.733 0.247 0.396 0.732 -0.002 -0.002 -0.001 1260 0.247 0.395 0.728 0.245 0.393 0.726 -0.002 -0.002 -0.001 1266 0.245 0.392 0.722 0.243 0.390 0.720 -0.002 -0.002 -0.001 1272 0.243 0.389 0.716 0.241 0.387 0.714

-0.002 -0.002 -0.001 1266 0.245 0.392 0.722 0.243 0.390 0.720 -0.002 -0.002 -0.001 1272 0.243 0.389 0.716 0.241 0.387 0.714 -0.002 -0.002 -0.001 17 of 24

Existing Conditions Proposed Conditions Difference Time 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year (Min) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) 1278 0.241 0.386 0.710 0.239 0.384 0.709 -0.002 -0.002 -0.001 1284 0.240 0.383 0.705 0.237 0.381 0.704 -0.002 -0.002 -0.001 1290 0.238 0.380 0.700 0.236 0.379 0.699 -0.002 -0.002 -0.001 1296 0.236 0.377 0.694 0.234 0.375 0.693 -0.002 -0.002 -0.001 1302 0.234 0.374 0.688 0.232 0.372 0.687 -0.002 -0.002 -0.001 1308 0.232 0.371 0.682 0.230 0.369 0.681 -0.002 -0.002 -0.001 1314 0.230 0.368 0.677 0.228 0.366 0.676 -0.002 -0.002 -0.001 1320 0.229 0.365 0.672 0.227 0.364 0.671 -0.002 -0.002 -0.001 1326 0.227 0.362 0.666 0.225 0.360 0.665 -0.002 -0.002 -0.001 1332 0.225 0.359 0.660 0.223 0.357 0.659 -0.002 -0.002 -0.001 1338 0.223 0.356 0.655 0.221 0.354 0.654 -0.002 -0.002 -0.001 1344 0.221 0.352 0.648 0.219 0.351 0.647 -0.002 -0.002 -0.001 1350 0.219 0.349 0.643 0.217 0.348 0.642 -0.002 -0.002 -0.001 1356 0.217 0.346 0.637 0.215 0.345 0.636 -0.002 -0.002 -0.001 1362 0.215 0.344 0.632 0.213 0.342 0.631 -0.002 -0.002 -0.001 1368 0.213 0.341 0.627 0.211 0.339 0.626 -0.002 -0.002 -0.001 1374 0.212 0.338 0.622 0.210 0.337 0.621 -0.002 -0.002 -0.001 1380 0.210 0.335 0.616 0.208 0.333 0.615 -0.002 -0.002 -0.001 1386 0.208 0.332 0.610 0.206 0.330 0.609 -0.002 -0.002 -0.001 1392 0.206 0.329 0.605 0.204 0.327 0.604 -0.002 -0.001 -0.001 1398 0.204 0.325 0.598 0.202 0.324 0.597 -0.002 -0.001

0.001 1392 0.206 0.329 0.605 0.204 0.327 0.604 -0.002 -0.001 -0.001 1398 0.204 0.325 0.598 0.202 0.324 0.597 -0.002 -0.001 -0.001 1404 0.202 0.322 0.593 0.200 0.321 0.591 -0.002 -0.001 -0.001 1410 0.200 0.319 0.587 0.198 0.318 0.586 -0.002 -0.001 -0.001 1416 0.198 0.316 0.582 0.196 0.315 0.581 -0.002 -0.001 -0.001 1422 0.196 0.314 0.577 0.195 0.312 0.576 -0.002 -0.001 -0.001 1428 0.194 0.310 0.571 0.193 0.309 0.570 -0.002 -0.001 -0.001 1434 0.192 0.307 0.565 0.191 0.306 0.564 -0.002 -0.001 -0.001 1440 0.191 0.305 0.560 0.189 0.303 0.559 -0.002 -0.001 -0.001 1446 0.152 0.242 0.446 0.151 0.241 0.445 -0.001 -0.001 -0.001 1452 0.076 0.121 0.223 0.075 0.121 0.222 -0.001 -0.001 0.000 1458 0.025 0.040 0.074 0.025 0.040 0.074 0.000 0.000 0.000 18 of 24

TABLE 10 DA-1 EXISTING VS. PROPOSED RUNOFF RATES - FUTURE PROJECTED RAINFALL Existing Conditions Proposed Conditions Difference Time 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year (Min) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) 0 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 6 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 12 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 18 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 24 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 30 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 36 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 42 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 48 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 54 0.000 0.000 0.002 0.000 0.000 0.002 0.000 0.000 0.000 60 0.000 0.000 0.002 0.000 0.000 0.002 0.000 0.000 0.000 66 0.000 0.001 0.002 0.000 0.001 0.002 0.000 0.000 0.000 72 0.000 0.001 0.003 0.000 0.001 0.003 0.000 0.000 0.000 78 0.000 0.001 0.003 0.000 0.001 0.003 0.000 0.000 0.000 84 0.000 0.001 0.003 0.000 0.001 0.003 0.000 0.000 0.000 90 0.000 0.001 0.003 0.000 0.001 0.003 0.000 0.000 0.000 96 0.000 0.001 0.004 0.000 0.001 0.004 0.000 0.000 0.000 102 0.000 0.001 0.004 0.000 0.001 0.004 0.000 0.000 0.000 108 0.001 0.001 0.004 0.001 0.001 0.004 0.000 0.000 0.000 114 0.001 0.002 0.004 0.001 0.002 0.004 0.000 0.000 0.000 120 0.001 0.002 0.004 0.001 0.002 0.004 0.000 0.000 0.000 126 0.001 0.002

0.002 0.004 0.001 0.002 0.004 0.000 0.000 0.000 120 0.001 0.002 0.004 0.001 0.002 0.004 0.000 0.000 0.000 126 0.001 0.002 0.004 0.001 0.002 0.004 0.000 0.000 0.000 132 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 138 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 144 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 150 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 156 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 162 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 168 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 174 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 180 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 186 0.001 0.002 0.005 0.001 0.002 0.005 0.000 0.000 0.000 192 0.001 0.003 0.005 0.001 0.003 0.005 0.000 0.000 0.000 198 0.001 0.003 0.006 0.001 0.003 0.006 0.000 0.000 0.000 204 0.001 0.003 0.006 0.001 0.003 0.006 0.000 0.000 0.000 210 0.001 0.003 0.006 0.001 0.003 0.006 0.000 0.000 0.000 216 0.001 0.003 0.006 0.001 0.003 0.006 0.000 0.000 0.000 222 0.002 0.003 0.006 0.002 0.003 0.006 0.000 0.000 0.000 228 0.002 0.003 0.007 0.002 0.003 0.007 0.000 0.000 0.000 234 0.002 0.003 0.007 0.002 0.003 0.007 0.000 0.000 0.000 240 0.002 0.003 0.007 0.002 0.003 0.007 0.000 0.000 0.000 19 of 24

Existing Conditions Proposed Conditions Difference Time 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year 2-Year 10-Year 100-Year (Min) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) 246 0.002 0.003 0.008 0.002 0.003 0.008 0.000 0.000 0.000 252 0.002 0.003 0.008 0.002 0.003 0.008 0.000 0.000 0.000 258 0.002 0.003 0.008 0.002 0.003 0.008 0.000 0.000 0.000 264 0.002 0.003 0.009 0.002 0.003 0.009 0.000 0.000 0.000 270 0.002 0.003 0.009 0.002 0.003 0.009 0.000 0.000 0.000 276 0.002 0.003 0.010 0.002 0.003 0.010 0.000 0.000 0.000 282 0.002 0.003 0.010 0.002 0.003 0.010 0.000 0.000 0.000 288 0.002 0.003 0.010 0.002 0.003 0.010 0.000 0.000 0.000 294 0.002 0.003 0.011 0.002 0.003 0.011 0.000 0.000 0.000 300 0.002 0.003 0.011 0.002 0.003 0.011 0.000 0.000 0.000 306 0.002 0.003 0.011 0.002 0.003 0.011 0.000 0.000 0.000 312 0.002 0.004 0.012 0.002 0.004 0.012 0.000 0.000 0.000 318 0.002 0.004 0.012 0.002 0.004 0.012 0.000 0.000 0.000 324 0.002 0.004 0.013 0.002 0.004 0.013 0.000 0.000 0.000 330 0.002 0.004 0.013 0.002 0.004 0.013 0.000 0.000 0.000 336 0.002 0.004 0.013 0.002 0.004 0.013 0.000 0.000 0.000 342 0.002 0.004 0.014 0.002 0.004 0.014 0.000 0.000 0.000 348 0.002 0.004 0.014 0.002 0.004 0.014 0.000 0.000 0.000 354 0.002 0.004 0.014 0.002 0.004 0.014 0.000 0.000 0.000 360 0.002 0.004 0.015 0.002 0.004 0.015 0.000 0.000 0.000 366 0.002 0.004 0.015 0.002 0.004 0.015 0.000 0.000 0.000 372 0.002

0.004 0.015 0.002 0.004 0.015 0.000 0.000 0.000 366 0.002 0.004 0.015 0.002 0.004 0.015 0.000 0.000 0.000 372 0.002 0.004 0.016 0.002 0.004 0.016 0.000 0.000 0.000 378 0.002 0.005 0.016 0.002 0.005 0.016 0.000 0.000 0.000 384 0.002 0.005 0.017 0.002 0.005 0.017 0.000 0.000 0.000 390 0.003 0.005 0.018 0.003 0.005 0.018 0.000 0.000 0.000 396 0.003 0.006 0.018 0.003 0.006 0.018 0.000 0.000 0.000 402 0.003 0.006 0.019 0.003 0.006 0.019 0.000 0.000 0.000 408 0.003 0.006 0.020 0.003 0.006 0.020 0.000 0.000 0.000 414 0.003 0.006 0.021 0.003 0.006 0.021 0.000 0.000 0.000 420 0.003 0.007 0.021 0.003 0.007 0.021 0.000 0.000 0.000 426 0.003 0.007 0.022 0.003 0.007 0.022 0.000 0.000 0.000 432 0.003 0.007 0.023 0.003 0.007 0.023 0.000 0.000 0.000 438 0.003 0.008 0.024 0.003 0.008 0.024 0.000 0.000 0.000 444 0.003 0.008 0.025 0.003 0.008 0.025 0.000 0.000 0.000 450 0.003 0.008 0.025 0.003 0.008 0.025 0.000 0.000 0.000 456 0.003 0.009 0.026 0.003 0.009 0.026 0.000 0.000 0.000 462 0.003 0.009 0.027 0.003 0.009 0.027 0.000 0.000 0.000 468 0.003 0.010 0.028 0.003 0.010 0.028 0.000 0.000 0.000 474 0.004 0.010 0.029 0.004 0.010 0.029 0.000 0.000 0.000 480 0.004 0.010 0.030 0.004 0.010 0.030 0.000 0.000 0.000 486 0.004 0.011 0.031 0.004 0.011 0.031 0.000 0.000 0.000 492 0.004 0.011 0.031 0.004 0.011 0.031 0.000 0.000 0.000 498 0.004 0.012 0.032 0.004 0.012 0.032 0.000 0.000 0.000

0.011 0.031 0.004 0.011 0.031 0.000 0.000 0.000 498 0.004 0.012 0.032 0.004 0.012 0.032 0.000 0.000 0.000 20 of 24