The Dredge by Brendan Flaherty

In Brendan Flaherty's debut novel, two estranged brothers must confront the violence of the past when they find out a pond where they played as children will be dredged.
After some traumatic teenaged years in rural Connecticut, Cale and Ambrose Casey had nothing left to say to each other. Cale ran off to Hawaii to sell luxury real estate. Ambrose stayed behind and built up his construction company. Neither thought they'd be in touch again and were glad for it-until they learned of a real estate developer's plan to drain and expand Gibbs Pond.
Nearly 30 years before, the Casey brothers buried a secret in that pond, which fell somewhere between self-defense and family preservation.
Lily Rowe, the contractor in charge of the dredging, can also trace her roots-and her trauma-to the banks of Gibbs Pond. After a childhood that saw her and her brother yanked across the country by her abusive father, it was here where she finally stayed put, even if they didn't. But as ambitious as Lily is, and as much as she wants answers of her own, her family also has secrets to protect.
Now, the haunted lives of Cale, Ambrose, and Lily collide once more as they reunite to unearth the devastation of the past.