Ep. 10.61.1Tū quidem, domine, prōvidentissimē verēris,nē commissus flūminī atque ita marī lacus effluat;You fear, sir, with the greatest foresight, that the lake, if joined to the river and so to the sea, may drain away; Ep. 10.61.1sed ego in rē praesentī invēnisse videor, quem ad modum huic perīculō occurrerem.but I, on the spot, think I have found a way to meet this danger. Ep. 10.61.2Potest enim lacus fossā ūsque ad flūmen addūcī nec tamen in flūmen ēmittī, sed relictō quasi margine continērī pariter et dirimī.For the lake can be brought by a canal right up to the river and yet not let out into the river, but, by leaving a sort of bank, be both held in and kept apart. Ep. 10.61.2Sīc cōnsequēmur, ut neque aquā viduētur flūminī mīxtus et sit perinde ac sī misceātur.In this way we shall bring it about that the lake is not robbed of its water by being mixed with the river, and yet it will be just as if it were mixed. Ep. 10.61.2Erit enim facile per illam brevissimam terram, quae interiacēbit, advecta fossā onera trānspōnere in flūmen.For it will be easy to transfer loads brought along the canal across that very narrow strip of land which will lie between, into the river.
Ep. 10.61.3Quod ita fīet sī necessitās cōget, et - spērō - nōn cōget.This will be done if necessity compels, and, I hope, it will not compel. Ep. 10.61.3Est enim et lacus ipse satis altus et nunc in contrāriam partem flūmen ēmittit, quod interclūsum inde et quō volumus āversum, sine ūllō dētrīmentō lacūs tantum aquae quantum nunc portat effundet.For the lake itself is quite deep, and at present it lets a river out on the opposite side; if this is dammed there and turned where we wish, it will pour in as much water as it now carries, without any loss to the lake. Ep. 10.61.3Praetereā per id spatium, per quod fossa fodienda est, incidunt rīvī;Besides, streams cross the stretch through which the canal is to be dug; Ep. 10.61.3quī sī dīligenter colligantur, augēbunt illud quod lacus dederit.and if these are carefully gathered together, they will increase what the lake supplies. Ep. 10.61.4Enimvērō, sī placeat fossam longius dūcere et altius pressam marī aequāre nec in flūmen, sed in ipsum mare ēmittere, repercussus maris servābit et reprimet, quidquid ē lacū veniet.Again, if it should be decided to carry the canal further and, by cutting it deeper, to bring it level with the sea and let it out not into the river but into the sea itself, the back-pressure of the sea will keep in and hold back whatever comes from the lake.
Ep. 10.61.4Quōrum sī nihil nōbīs locī nātūra praestāret, expedītum tamen erat cataractīs aquae cursum temperāre.Even if the nature of the place provided us with none of these things, it would still be easy to regulate the flow of the water with sluices. Ep. 10.61.5Vērum et haec et alia multō sagācius conquīret explōrābitque lībrātor, quem plānē, domine, dēbēs mittere, ut pollicēris.But these and other things will be investigated and explored far more shrewdly by a surveyor, whom you certainly ought to send, sir, as you promise. Ep. 10.61.5Est enim rēs digna et magnitūdine tuā et cūrā.For the undertaking is worthy both of your greatness and of your care. Ep. 10.61.5Ego interim Calpurniō Macrō clārissimō virō auctōre tē scrīpsī, ut lībrātōrem quam maximē idōneum mitteret.Meanwhile, on your authority, I have written to Calpurnius Macer, a most distinguished man, to send the most suitable surveyor possible.